Unggahan File di ASP.NET Core Blazor

Pengguna kontainer Inversion of Control (IoC) Autofac

Jika Anda menggunakan Autofac Inversion of Control (IoC) container alih-alih kontainer injeksi dependensi ASP.NET Core bawaan, atur DisableImplicitFromServicesParameters ke true dalam opsi hub penangan sirkuit sisi server. Untuk informasi selengkapnya, lihat FileUpload: Tidak menerima data apa pun dalam waktu yang dialokasikan (dotnet/aspnetcore #38842).

Untuk browser berbasis Chromium (misalnya, Google Chrome dan Microsoft Edge) yang menggunakan protokol HTTP/2, HTTPS, dan CORS, dukungan klien sisi Blazor menggunakan Streams API untuk memungkinkan pengunggahan file besar dengan streaming permintaan .

Tanpa browser Chromium, protokol HTTP/2, atau HTTPS, pada bagian klien Blazor membaca byte file ke dalam satu array buffer JavaScript saat memindahkan data dari JavaScript ke C#, yang terbatas pada 2 GB atau sesuai memori perangkat yang tersedia. Unggahan file besar mungkin gagal untuk unggahan sisi klien menggunakan komponen InputFile.

Sisi klien Blazor membaca byte dari file ke dalam sebuah buffer array JavaScript tunggal saat mentransfer data dari JavaScript ke C#, yang dibatasi hingga 2 GB atau sesuai dengan memori perangkat yang tersedia. Unggahan file besar mungkin gagal ketika diunggah dari sisi klien menggunakan komponen InputFile. Kami merekomendasikan mengadopsi streaming permintaan dengan ASP.NET Core 9.0 atau versi lebih baru.

@page "/file-upload-1"
@using System 
@using System.IO
@using Microsoft.AspNetCore.Hosting
@inject ILogger<FileUpload1> Logger
@inject IWebHostEnvironment Environment

<PageTitle>File Upload 1</PageTitle>

<h1>File Upload Example 1</h1>

<p>
    <label>
        Max file size:
        <input type="number" @bind="maxFileSize" />
    </label>
</p>

<p>
    <label>
        Max allowed files:
        <input type="number" @bind="maxAllowedFiles" />
    </label>
</p>

<p>
    <label>
        Upload up to @maxAllowedFiles of up to @maxFileSize bytes:
        <InputFile OnChange="LoadFiles" multiple />
    </label>
</p>

@if (isLoading)
{
    <p>Uploading...</p>
}
else
{
    <ul>
        @foreach (var file in loadedFiles)
        {
            <li>
                <ul>
                    <li>Name: @file.Name</li>
                    <li>Last modified: @file.LastModified.ToString()</li>
                    <li>Size (bytes): @file.Size</li>
                    <li>Content type: @file.ContentType</li>
                </ul>
            </li>
        }
    </ul>
}

@code {
    private List<IBrowserFile> loadedFiles = [];
    private long maxFileSize = 1024 * 15;
    private int maxAllowedFiles = 3;
    private bool isLoading;

    private async Task LoadFiles(InputFileChangeEventArgs e)
    {
        isLoading = true;
        loadedFiles.Clear();

        foreach (var file in e.GetMultipleFiles(maxAllowedFiles))
        {
            try
            {
                var trustedFileName = Path.GetRandomFileName();
                var path = Path.Combine(Environment.ContentRootPath,
                    Environment.EnvironmentName, "unsafe_uploads",
                    trustedFileName);

                await using FileStream fs = new(path, FileMode.Create);
                await file.OpenReadStream(maxFileSize).CopyToAsync(fs);

                loadedFiles.Add(file);

                Logger.LogInformation(
                    "Unsafe Filename: {UnsafeFilename} File saved: {Filename}",
                    file.Name, trustedFileName);
            }
            catch (Exception ex)
            {
                Logger.LogError("File: {Filename} Error: {Error}", 
                    file.Name, ex.Message);
            }
        }

        isLoading = false;
    }
}

@page "/file-upload-1"
@using System 
@using System.IO
@using Microsoft.AspNetCore.Hosting
@using Microsoft.Extensions.Logging
@inject ILogger<FileUpload1> Logger
@inject IWebHostEnvironment Environment

<h3>Upload Files</h3>

<p>
    <label>
        Max file size:
        <input type="number" @bind="maxFileSize" />
    </label>
</p>

<p>
    <label>
        Max allowed files:
        <input type="number" @bind="maxAllowedFiles" />
    </label>
</p>

<p>
    <label>
        Upload up to @maxAllowedFiles of up to @maxFileSize bytes:
        <InputFile OnChange="LoadFiles" multiple />
    </label>
</p>

@if (isLoading)
{
    <p>Uploading...</p>
}
else
{
    <ul>
        @foreach (var file in loadedFiles)
        {
            <li>
                <ul>
                    <li>Name: @file.Name</li>
                    <li>Last modified: @file.LastModified.ToString()</li>
                    <li>Size (bytes): @file.Size</li>
                    <li>Content type: @file.ContentType</li>
                </ul>
            </li>
        }
    </ul>
}

@code {
    private List<IBrowserFile> loadedFiles = new();
    private long maxFileSize = 1024 * 15;
    private int maxAllowedFiles = 3;
    private bool isLoading;

    private async Task LoadFiles(InputFileChangeEventArgs e)
    {
        isLoading = true;
        loadedFiles.Clear();

        foreach (var file in e.GetMultipleFiles(maxAllowedFiles))
        {
            try
            {
                loadedFiles.Add(file);

                var trustedFileNameForFileStorage = Path.GetRandomFileName();
                var path = Path.Combine(Environment.ContentRootPath,
                        Environment.EnvironmentName, "unsafe_uploads",
                        trustedFileNameForFileStorage);

                await using FileStream fs = new(path, FileMode.Create);
                await file.OpenReadStream(maxFileSize).CopyToAsync(fs);
            }
            catch (Exception ex)
            {
                Logger.LogError("File: {Filename} Error: {Error}", 
                    file.Name, ex.Message);
            }
        }

        isLoading = false;
    }
}

@page "/file-upload-1"
@using System 
@using System.IO
@using Microsoft.AspNetCore.Hosting
@using Microsoft.Extensions.Logging
@inject ILogger<FileUpload1> Logger
@inject IWebHostEnvironment Environment

<h3>Upload Files</h3>

<p>
    <label>
        Max file size:
        <input type="number" @bind="maxFileSize" />
    </label>
</p>

<p>
    <label>
        Max allowed files:
        <input type="number" @bind="maxAllowedFiles" />
    </label>
</p>

<p>
    <label>
        Upload up to @maxAllowedFiles of up to @maxFileSize bytes:
        <InputFile OnChange="LoadFiles" multiple />
    </label>
</p>

@if (isLoading)
{
    <p>Uploading...</p>
}
else
{
    <ul>
        @foreach (var file in loadedFiles)
        {
            <li>
                <ul>
                    <li>Name: @file.Name</li>
                    <li>Last modified: @file.LastModified.ToString()</li>
                    <li>Size (bytes): @file.Size</li>
                    <li>Content type: @file.ContentType</li>
                </ul>
            </li>
        }
    </ul>
}

@code {
    private List<IBrowserFile> loadedFiles = new();
    private long maxFileSize = 1024 * 15;
    private int maxAllowedFiles = 3;
    private bool isLoading;

    private async Task LoadFiles(InputFileChangeEventArgs e)
    {
        isLoading = true;
        loadedFiles.Clear();

        foreach (var file in e.GetMultipleFiles(maxAllowedFiles))
        {
            try
            {
                loadedFiles.Add(file);

                var trustedFileNameForFileStorage = Path.GetRandomFileName();
                var path = Path.Combine(Environment.ContentRootPath,
                        Environment.EnvironmentName, "unsafe_uploads",
                        trustedFileNameForFileStorage);

                await using FileStream fs = new(path, FileMode.Create);
                await file.OpenReadStream(maxFileSize).CopyToAsync(fs);
            }
            catch (Exception ex)
            {
                Logger.LogError("File: {Filename} Error: {Error}", 
                    file.Name, ex.Message);
            }
        }

        isLoading = false;
    }
}

@page "/file-upload-1"
@using System 
@using System.IO
@using Microsoft.AspNetCore.Hosting
@using Microsoft.Extensions.Logging
@inject ILogger<FileUpload1> Logger
@inject IWebHostEnvironment Environment

<h3>Upload Files</h3>

<p>
    <label>
        Max file size:
        <input type="number" @bind="maxFileSize" />
    </label>
</p>

<p>
    <label>
        Max allowed files:
        <input type="number" @bind="maxAllowedFiles" />
    </label>
</p>

<p>
    <label>
        Upload up to @maxAllowedFiles of up to @maxFileSize bytes:
        <InputFile OnChange="LoadFiles" multiple />
    </label>
</p>

@if (isLoading)
{
    <p>Uploading...</p>
}
else
{
    <ul>
        @foreach (var file in loadedFiles)
        {
            <li>
                <ul>
                    <li>Name: @file.Name</li>
                    <li>Last modified: @file.LastModified.ToString()</li>
                    <li>Size (bytes): @file.Size</li>
                    <li>Content type: @file.ContentType</li>
                </ul>
            </li>
        }
    </ul>
}

@code {
    private List<IBrowserFile> loadedFiles = new();
    private long maxFileSize = 1024 * 15;
    private int maxAllowedFiles = 3;
    private bool isLoading;

    private async Task LoadFiles(InputFileChangeEventArgs e)
    {
        isLoading = true;
        loadedFiles.Clear();

        foreach (var file in e.GetMultipleFiles(maxAllowedFiles))
        {
            try
            {
                loadedFiles.Add(file);

                var trustedFileNameForFileStorage = Path.GetRandomFileName();
                var path = Path.Combine(Environment.ContentRootPath,
                        Environment.EnvironmentName, "unsafe_uploads",
                        trustedFileNameForFileStorage);

                await using FileStream fs = new(path, FileMode.Create);
                await file.OpenReadStream(maxFileSize).CopyToAsync(fs);
            }
            catch (Exception ex)
            {
                Logger.LogError("File: {Filename} Error: {Error}", 
                    file.Name, ex.Message);
            }
        }

        isLoading = false;
    }
}

@page "/file-upload-1"
@inject ILogger<FileUpload1> Logger

<PageTitle>File Upload 1</PageTitle>

<h1>File Upload Example 1</h1>

<p>
    <label>
        Max file size:
        <input type="number" @bind="maxFileSize" />
    </label>
</p>

<p>
    <label>
        Max allowed files:
        <input type="number" @bind="maxAllowedFiles" />
    </label>
</p>

<p>
    <label>
        Upload up to @maxAllowedFiles of up to @maxFileSize bytes:
        <InputFile OnChange="LoadFiles" multiple />
    </label>
</p>

@if (isLoading)
{
    <p>Uploading...</p>
}
else
{
    <ul>
        @foreach (var file in loadedFiles)
        {
            <li>
                <ul>
                    <li>Name: @file.Name</li>
                    <li>Last modified: @file.LastModified.ToString()</li>
                    <li>Size (bytes): @file.Size</li>
                    <li>Content type: @file.ContentType</li>
                </ul>
            </li>
        }
    </ul>
}

@code {
    private List<IBrowserFile> loadedFiles = [];
    private long maxFileSize = 1024 * 15;
    private int maxAllowedFiles = 3;
    private bool isLoading;

    private void LoadFiles(InputFileChangeEventArgs e)
    {
        isLoading = true;
        loadedFiles.Clear();

        foreach (var file in e.GetMultipleFiles(maxAllowedFiles))
        {
            try
            {
                loadedFiles.Add(file);
            }
            catch (Exception ex)
            {
                Logger.LogError("File: {FileName} Error: {Error}", 
                    file.Name, ex.Message);
            }
        }

        isLoading = false;
    }
}

@page "/file-upload-1"
@using Microsoft.Extensions.Logging
@inject ILogger<FileUpload1> Logger

<h3>Upload Files</h3>

<p>
    <label>
        Max file size:
        <input type="number" @bind="maxFileSize" />
    </label>
</p>

<p>
    <label>
        Max allowed files:
        <input type="number" @bind="maxAllowedFiles" />
    </label>
</p>

<p>
    <label>
        Upload up to @maxAllowedFiles of up to @maxFileSize bytes:
        <InputFile OnChange="LoadFiles" multiple />
    </label>
</p>

@if (isLoading)
{
    <p>Uploading...</p>
}
else
{
    <ul>
        @foreach (var file in loadedFiles)
        {
            <li>
                <ul>
                    <li>Name: @file.Name</li>
                    <li>Last modified: @file.LastModified.ToString()</li>
                    <li>Size (bytes): @file.Size</li>
                    <li>Content type: @file.ContentType</li>
                </ul>
            </li>
        }
    </ul>
}

@code {
    private List<IBrowserFile> loadedFiles = new();
    private long maxFileSize = 1024 * 15;
    private int maxAllowedFiles = 3;
    private bool isLoading;

    private void LoadFiles(InputFileChangeEventArgs e)
    {
        isLoading = true;
        loadedFiles.Clear();

        foreach (var file in e.GetMultipleFiles(maxAllowedFiles))
        {
            try
            {
                loadedFiles.Add(file);
            }
            catch (Exception ex)
            {
                Logger.LogError("File: {FileName} Error: {Error}", 
                    file.Name, ex.Message);
            }
        }

        isLoading = false;
    }
}

@page "/file-upload-1"
@using Microsoft.Extensions.Logging
@inject ILogger<FileUpload1> Logger

<h3>Upload Files</h3>

<p>
    <label>
        Max file size:
        <input type="number" @bind="maxFileSize" />
    </label>
</p>

<p>
    <label>
        Max allowed files:
        <input type="number" @bind="maxAllowedFiles" />
    </label>
</p>

<p>
    <label>
        Upload up to @maxAllowedFiles of up to @maxFileSize bytes:
        <InputFile OnChange="LoadFiles" multiple />
    </label>
</p>

@if (isLoading)
{
    <p>Uploading...</p>
}
else
{
    <ul>
        @foreach (var file in loadedFiles)
        {
            <li>
                <ul>
                    <li>Name: @file.Name</li>
                    <li>Last modified: @file.LastModified.ToString()</li>
                    <li>Size (bytes): @file.Size</li>
                    <li>Content type: @file.ContentType</li>
                </ul>
            </li>
        }
    </ul>
}

@code {
    private List<IBrowserFile> loadedFiles = new();
    private long maxFileSize = 1024 * 15;
    private int maxAllowedFiles = 3;
    private bool isLoading;

    private void LoadFiles(InputFileChangeEventArgs e)
    {
        isLoading = true;
        loadedFiles.Clear();

        foreach (var file in e.GetMultipleFiles(maxAllowedFiles))
        {
            try
            {
                loadedFiles.Add(file);
            }
            catch (Exception ex)
            {
                Logger.LogError("File: {Filename} Error: {Error}", 
                    file.Name, ex.Message);
            }
        }

        isLoading = false;
    }
}

@page "/file-upload-1"
@using Microsoft.Extensions.Logging
@inject ILogger<FileUpload1> Logger

<h3>Upload Files</h3>

<p>
    <label>
        Max file size:
        <input type="number" @bind="maxFileSize" />
    </label>
</p>

<p>
    <label>
        Max allowed files:
        <input type="number" @bind="maxAllowedFiles" />
    </label>
</p>

<p>
    <label>
        Upload up to @maxAllowedFiles of up to @maxFileSize bytes:
        <InputFile OnChange="LoadFiles" multiple />
    </label>
</p>

@if (isLoading)
{
    <p>Uploading...</p>
}
else
{
    <ul>
        @foreach (var file in loadedFiles)
        {
            <li>
                <ul>
                    <li>Name: @file.Name</li>
                    <li>Last modified: @file.LastModified.ToString()</li>
                    <li>Size (bytes): @file.Size</li>
                    <li>Content type: @file.ContentType</li>
                </ul>
            </li>
        }
    </ul>
}

@code {
    private List<IBrowserFile> loadedFiles = new();
    private long maxFileSize = 1024 * 15;
    private int maxAllowedFiles = 3;
    private bool isLoading;

    private void LoadFiles(InputFileChangeEventArgs e)
    {
        isLoading = true;
        loadedFiles.Clear();

        foreach (var file in e.GetMultipleFiles(maxAllowedFiles))
        {
            try
            {
                loadedFiles.Add(file);
            }
            catch (Exception ex)
            {
                Logger.LogError("File: {Filename} Error: {Error}", 
                    file.Name, ex.Message);
            }
        }

        isLoading = false;
    }
}

using Microsoft.AspNetCore.Components.Forms;
using System.Diagnostics.CodeAnalysis;

namespace BlazorSample;

internal sealed class LazyBrowserFileStream(IBrowserFile file, int maxAllowedSize) 
    : Stream
{
    private readonly IBrowserFile file = file;
    private readonly int maxAllowedSize = maxAllowedSize;
    private Stream? underlyingStream;
    private bool isDisposed;

    public override bool CanRead => true;

    public override bool CanSeek => false;

    public override bool CanWrite => false;

    public override long Length => file.Size;

    public override long Position
    {
        get => underlyingStream?.Position ?? 0;
        set => throw new NotSupportedException();
    }

    public override void Flush() => underlyingStream?.Flush();

    public override Task<int> ReadAsync(byte[] buffer, int offset, int count, 
        CancellationToken cancellationToken)
    {
        EnsureStreamIsOpen();

        return underlyingStream.ReadAsync(buffer, offset, count, cancellationToken);
    }

    public override ValueTask<int> ReadAsync(Memory<byte> buffer, 
        CancellationToken cancellationToken = default)
    {
        EnsureStreamIsOpen();
        return underlyingStream.ReadAsync(buffer, cancellationToken);
    }

    [MemberNotNull(nameof(underlyingStream))]
    private void EnsureStreamIsOpen() => 
        underlyingStream ??= file.OpenReadStream(maxAllowedSize);

    protected override void Dispose(bool disposing)
    {
        if (isDisposed)
        {
            return;
        }

        underlyingStream?.Dispose();
        isDisposed = true;

        base.Dispose(disposing);
    }

    public override int Read(byte[] buffer, int offset, int count)
        => throw new NotSupportedException();

    public override long Seek(long offset, SeekOrigin origin)
        => throw new NotSupportedException();

    public override void SetLength(long value)
        => throw new NotSupportedException();

    public override void Write(byte[] buffer, int offset, int count)
        => throw new NotSupportedException();
}

using Microsoft.AspNetCore.Components.Forms;
using System.Diagnostics.CodeAnalysis;

namespace BlazorSample;

internal sealed class LazyBrowserFileStream : Stream
{
    private readonly IBrowserFile file;
    private readonly int maxAllowedSize;
    private Stream? underlyingStream;
    private bool isDisposed;

    public override bool CanRead => true;

    public override bool CanSeek => false;

    public override bool CanWrite => false;

    public override long Length => file.Size;

    public override long Position
    {
        get => underlyingStream?.Position ?? 0;
        set => throw new NotSupportedException();
    }

    public LazyBrowserFileStream(IBrowserFile file, int maxAllowedSize)
    {
        this.file = file;
        this.maxAllowedSize = maxAllowedSize;
    }

    public override void Flush()
    {
        underlyingStream?.Flush();
    }

    public override Task<int> ReadAsync(byte[] buffer, int offset, int count, 
        CancellationToken cancellationToken)
    {
        EnsureStreamIsOpen();

        return underlyingStream.ReadAsync(buffer, offset, count, cancellationToken);
    }

    public override ValueTask<int> ReadAsync(Memory<byte> buffer, 
        CancellationToken cancellationToken = default)
    {
        EnsureStreamIsOpen();
        return underlyingStream.ReadAsync(buffer, cancellationToken);
    }

    [MemberNotNull(nameof(underlyingStream))]
    private void EnsureStreamIsOpen()
    {
        underlyingStream ??= file.OpenReadStream(maxAllowedSize);
    }

    protected override void Dispose(bool disposing)
    {
        if (isDisposed)
        {
            return;
        }

        underlyingStream?.Dispose();
        isDisposed = true;

        base.Dispose(disposing);
    }

    public override int Read(byte[] buffer, int offset, int count)
        => throw new NotSupportedException();

    public override long Seek(long offset, SeekOrigin origin)
        => throw new NotSupportedException();

    public override void SetLength(long value)
        => throw new NotSupportedException();

    public override void Write(byte[] buffer, int offset, int count)
        => throw new NotSupportedException();
}

using Microsoft.AspNetCore.Components.Forms;
using System.Diagnostics.CodeAnalysis;

namespace BlazorSample;

internal sealed class LazyBrowserFileStream : Stream
{
    private readonly IBrowserFile file;
    private readonly int maxAllowedSize;
    private Stream? underlyingStream;
    private bool isDisposed;

    public override bool CanRead => true;

    public override bool CanSeek => false;

    public override bool CanWrite => false;

    public override long Length => file.Size;

    public override long Position
    {
        get => underlyingStream?.Position ?? 0;
        set => throw new NotSupportedException();
    }

    public LazyBrowserFileStream(IBrowserFile file, int maxAllowedSize)
    {
        this.file = file;
        this.maxAllowedSize = maxAllowedSize;
    }

    public override void Flush()
    {
        underlyingStream?.Flush();
    }

    public override Task<int> ReadAsync(byte[] buffer, int offset, int count, 
        CancellationToken cancellationToken)
    {
        EnsureStreamIsOpen();

        return underlyingStream.ReadAsync(buffer, offset, count, cancellationToken);
    }

    public override ValueTask<int> ReadAsync(Memory<byte> buffer, 
        CancellationToken cancellationToken = default)
    {
        EnsureStreamIsOpen();
        return underlyingStream.ReadAsync(buffer, cancellationToken);
    }

    [MemberNotNull(nameof(underlyingStream))]
    private void EnsureStreamIsOpen()
    {
        underlyingStream ??= file.OpenReadStream(maxAllowedSize);
    }

    protected override void Dispose(bool disposing)
    {
        if (isDisposed)
        {
            return;
        }

        underlyingStream?.Dispose();
        isDisposed = true;

        base.Dispose(disposing);
    }

    public override int Read(byte[] buffer, int offset, int count)
        => throw new NotSupportedException();

    public override long Seek(long offset, SeekOrigin origin)
        => throw new NotSupportedException();

    public override void SetLength(long value)
        => throw new NotSupportedException();

    public override void Write(byte[] buffer, int offset, int count)
        => throw new NotSupportedException();
}

using System;
using System.Diagnostics.CodeAnalysis;
using System.IO;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Components.Forms;

namespace BlazorSample;

internal sealed class LazyBrowserFileStream : Stream
{
    private readonly IBrowserFile file;
    private readonly int maxAllowedSize;
    private Stream underlyingStream;
    private bool isDisposed;

    public override bool CanRead => true;

    public override bool CanSeek => false;

    public override bool CanWrite => false;

    public override long Length => file.Size;

    public override long Position
    {
        get => underlyingStream?.Position ?? 0;
        set => throw new NotSupportedException();
    }

    public LazyBrowserFileStream(IBrowserFile file, int maxAllowedSize)
    {
        this.file = file;
        this.maxAllowedSize = maxAllowedSize;
    }

    public override void Flush()
    {
        underlyingStream?.Flush();
    }

    public override Task<int> ReadAsync(byte[] buffer, int offset, int count, 
        CancellationToken cancellationToken)
    {
        EnsureStreamIsOpen();

        return underlyingStream.ReadAsync(buffer, offset, count, cancellationToken);
    }

    public override ValueTask<int> ReadAsync(Memory<byte> buffer, 
        CancellationToken cancellationToken = default)
    {
        EnsureStreamIsOpen();
        return underlyingStream.ReadAsync(buffer, cancellationToken);
    }

    [MemberNotNull(nameof(underlyingStream))]
    private void EnsureStreamIsOpen()
    {
        underlyingStream ??= file.OpenReadStream(maxAllowedSize);
    }

    protected override void Dispose(bool disposing)
    {
        if (isDisposed)
        {
            return;
        }

        underlyingStream?.Dispose();
        isDisposed = true;

        base.Dispose(disposing);
    }

    public override int Read(byte[] buffer, int offset, int count)
        => throw new NotSupportedException();

    public override long Seek(long offset, SeekOrigin origin)
        => throw new NotSupportedException();

    public override void SetLength(long value)
        => throw new NotSupportedException();

    public override void Write(byte[] buffer, int offset, int count)
        => throw new NotSupportedException();
}

@page "/file-upload-2"
@using System.Net.Http.Headers
@using System.Text.Json
@inject IHttpClientFactory ClientFactory
@inject ILogger<FileUpload2> Logger

<PageTitle>File Upload 2</PageTitle>

<h1>File Upload Example 2</h1>

<p>
    This example requires a backend server API to function. For more information, 
    see the <em>Upload files to a server</em> section 
    of the <em>ASP.NET Core Blazor file uploads</em> article.
</p>

<p>
    <label>
        Upload up to @maxAllowedFiles files:
        <InputFile OnChange="OnInputFileChange" multiple />
    </label>
</p>

@if (files.Any())
{
    <div class="card">
        <div class="card-body">
            <ul>
                @foreach (var file in files)
                {
                    <li>
                        File: @file.Name
                        <br>
                        @if (FileUpload(uploadResults, file.Name, Logger,
                           out var result))
                        {
                            <span>
                                Stored File Name: @result.StoredFileName
                            </span>
                        }
                        else
                        {
                            <span>
                                There was an error uploading the file
                                (Error: @result.ErrorCode).
                            </span>
                        }
                    </li>
                }
            </ul>
        </div>
    </div>
}

@code {
    private List<File> files = [];
    private List<UploadResult> uploadResults = [];
    private int maxAllowedFiles = 3;
    private bool shouldRender;

    protected override bool ShouldRender() => shouldRender;

    private async Task OnInputFileChange(InputFileChangeEventArgs e)
    {
        shouldRender = false;
        int maxFileSize = 1024 * 15;
        var upload = false;

        using var content = new MultipartFormDataContent();

        foreach (var file in e.GetMultipleFiles(maxAllowedFiles))
        {
            if (uploadResults.SingleOrDefault(
                f => f.FileName == file.Name) is null)
            {
                try
                {
                    files.Add(new() { Name = file.Name });

                    var stream = new LazyBrowserFileStream(file, maxFileSize);
                    var fileContent = new StreamContent(stream);

                    fileContent.Headers.ContentType = 
                        new MediaTypeHeaderValue(file.ContentType);

                    content.Add(
                        content: fileContent,
                        name: "\"files\"",
                        fileName: file.Name);

                    upload = true;
                }
                catch (Exception ex)
                {
                    Logger.LogInformation(
                        "{FileName} not uploaded (Err: 6): {Message}", 
                        file.Name, ex.Message);

                    uploadResults.Add(
                        new()
                        {
                            FileName = file.Name, 
                            ErrorCode = 6, 
                            Uploaded = false
                        });
                }
            }
        }

        if (upload)
        {
            var client = ClientFactory.CreateClient();

            var response = 
                await client.PostAsync("https://localhost:5001/Filesave", 
                content);

            if (response.IsSuccessStatusCode)
            {
                var options = new JsonSerializerOptions
                {
                    PropertyNameCaseInsensitive = true,
                };

                using var responseStream =
                    await response.Content.ReadAsStreamAsync();

                var newUploadResults = await JsonSerializer
                    .DeserializeAsync<IList<UploadResult>>(responseStream, options);

                if (newUploadResults is not null)
                {
                    uploadResults = uploadResults.Concat(newUploadResults).ToList();
                }
            }
        }

        shouldRender = true;
    }

    private static bool FileUpload(IList<UploadResult> uploadResults,
        string? fileName, ILogger<FileUpload2> logger, out UploadResult result)
    {
        result = uploadResults.SingleOrDefault(f => f.FileName == fileName) ?? new();

        if (!result.Uploaded)
        {
            logger.LogInformation("{FileName} not uploaded (Err: 5)", fileName);
            result.ErrorCode = 5;
        }

        return result.Uploaded;
    }

    private class File
    {
        public string? Name { get; set; }
    }
}

@page "/file-upload-2"
@using System.Net.Http.Headers
@using System.Text.Json
@inject IHttpClientFactory ClientFactory
@inject ILogger<FileUpload2> Logger

<h1>File Upload Example 2</h1>

<p>
    This example requires a backend server API to function. For more information, 
    see the <em>Upload files to a server</em> section 
    of the <em>ASP.NET Core Blazor file uploads</em> article.
</p>

<p>
    <label>
        Upload up to @maxAllowedFiles files:
        <InputFile OnChange="OnInputFileChange" multiple />
    </label>
</p>

@if (files.Count > 0)
{
    <div class="card">
        <div class="card-body">
            <ul>
                @foreach (var file in files)
                {
                    <li>
                        File: @file.Name
                        <br>
                        @if (FileUpload(uploadResults, file.Name, Logger,
                           out var result))
                        {
                            <span>
                                Stored File Name: @result.StoredFileName
                            </span>
                        }
                        else
                        {
                            <span>
                                There was an error uploading the file
                                (Error: @result.ErrorCode).
                            </span>
                        }
                    </li>
                }
            </ul>
        </div>
    </div>
}

@code {
    private List<File> files = new();
    private List<UploadResult> uploadResults = new();
    private int maxAllowedFiles = 3;
    private bool shouldRender;

    protected override bool ShouldRender() => shouldRender;

    private async Task OnInputFileChange(InputFileChangeEventArgs e)
    {
        shouldRender = false;
        int maxFileSize = 1024 * 15;
        var upload = false;

        using var content = new MultipartFormDataContent();

        foreach (var file in e.GetMultipleFiles(maxAllowedFiles))
        {
            if (uploadResults.SingleOrDefault(
                f => f.FileName == file.Name) is null)
            {
                try
                {
                    files.Add(new() { Name = file.Name });

                    var stream = new LazyBrowserFileStream(file, maxFileSize);
                    var fileContent = new StreamContent(stream);
                    fileContent.Headers.ContentType = 
                        new MediaTypeHeaderValue(file.ContentType);

                    content.Add(
                        content: fileContent,
                        name: "\"files\"",
                        fileName: file.Name);

                    upload = true;
                }
                catch (Exception ex)
                {
                    Logger.LogInformation(
                        "{FileName} not uploaded (Err: 6): {Message}", 
                        file.Name, ex.Message);

                    uploadResults.Add(
                        new()
                        {
                            FileName = file.Name, 
                            ErrorCode = 6, 
                            Uploaded = false
                        });
                }
            }
        }

        if (upload)
        {
            var client = ClientFactory.CreateClient();

            var response = 
                await client.PostAsync("https://localhost:5001/Filesave", 
                content);

            if (response.IsSuccessStatusCode)
            {
                var options = new JsonSerializerOptions
                {
                    PropertyNameCaseInsensitive = true,
                };

                using var responseStream =
                    await response.Content.ReadAsStreamAsync();

                var newUploadResults = await JsonSerializer
                    .DeserializeAsync<IList<UploadResult>>(responseStream, options);

                if (newUploadResults is not null)
                {
                    uploadResults = uploadResults.Concat(newUploadResults).ToList();
                }
            }
        }

        shouldRender = true;
    }

    private static bool FileUpload(IList<UploadResult> uploadResults,
        string? fileName, ILogger<FileUpload2> logger, out UploadResult result)
    {
        result = uploadResults.SingleOrDefault(f => f.FileName == fileName) ?? new();

        if (!result.Uploaded)
        {
            logger.LogInformation("{FileName} not uploaded (Err: 5)", fileName);
            result.ErrorCode = 5;
        }

        return result.Uploaded;
    }

    private class File
    {
        public string? Name { get; set; }
    }
}

@page "/file-upload-2"
@using System.Net.Http.Headers
@using System.Text.Json
@inject IHttpClientFactory ClientFactory
@inject ILogger<FileUpload2> Logger

<h1>File Upload Example 2</h1>

<p>
    This example requires a backend server API to function. For more information, 
    see the <em>Upload files to a server</em> section 
    of the <em>ASP.NET Core Blazor file uploads</em> article.
</p>

<p>
    <label>
        Upload up to @maxAllowedFiles files:
        <InputFile OnChange="OnInputFileChange" multiple />
    </label>
</p>

@if (files.Count > 0)
{
    <div class="card">
        <div class="card-body">
            <ul>
                @foreach (var file in files)
                {
                    <li>
                        File: @file.Name
                        <br>
                        @if (FileUpload(uploadResults, file.Name, Logger,
                           out var result))
                        {
                            <span>
                                Stored File Name: @result.StoredFileName
                            </span>
                        }
                        else
                        {
                            <span>
                                There was an error uploading the file
                                (Error: @result.ErrorCode).
                            </span>
                        }
                    </li>
                }
            </ul>
        </div>
    </div>
}

@code {
    private List<File> files = new();
    private List<UploadResult> uploadResults = new();
    private int maxAllowedFiles = 3;
    private bool shouldRender;

    protected override bool ShouldRender() => shouldRender;

    private async Task OnInputFileChange(InputFileChangeEventArgs e)
    {
        shouldRender = false;
        int maxFileSize = 1024 * 15;
        var upload = false;

        using var content = new MultipartFormDataContent();

        foreach (var file in e.GetMultipleFiles(maxAllowedFiles))
        {
            if (uploadResults.SingleOrDefault(
                f => f.FileName == file.Name) is null)
            {
                try
                {
                    files.Add(new() { Name = file.Name });

                    var stream = new LazyBrowserFileStream(file, maxFileSize);
                    var fileContent = new StreamContent(stream);
                    fileContent.Headers.ContentType = 
                        new MediaTypeHeaderValue(file.ContentType);

                    content.Add(
                        content: fileContent,
                        name: "\"files\"",
                        fileName: file.Name);

                    upload = true;
                }
                catch (Exception ex)
                {
                    Logger.LogInformation(
                        "{FileName} not uploaded (Err: 6): {Message}", 
                        file.Name, ex.Message);

                    uploadResults.Add(
                        new()
                        {
                            FileName = file.Name, 
                            ErrorCode = 6, 
                            Uploaded = false
                        });
                }
            }
        }

        if (upload)
        {
            var client = ClientFactory.CreateClient();

            var response = 
                await client.PostAsync("https://localhost:5001/Filesave", 
                content);

            if (response.IsSuccessStatusCode)
            {
                var options = new JsonSerializerOptions
                {
                    PropertyNameCaseInsensitive = true,
                };

                using var responseStream =
                    await response.Content.ReadAsStreamAsync();

                var newUploadResults = await JsonSerializer
                    .DeserializeAsync<IList<UploadResult>>(responseStream, options);

                if (newUploadResults is not null)
                {
                    uploadResults = uploadResults.Concat(newUploadResults).ToList();
                }
            }
        }

        shouldRender = true;
    }

    private static bool FileUpload(IList<UploadResult> uploadResults,
        string? fileName, ILogger<FileUpload2> logger, out UploadResult result)
    {
        result = uploadResults.SingleOrDefault(f => f.FileName == fileName) ?? new();

        if (!result.Uploaded)
        {
            logger.LogInformation("{FileName} not uploaded (Err: 5)", fileName);
            result.ErrorCode = 5;
        }

        return result.Uploaded;
    }

    private class File
    {
        public string? Name { get; set; }
    }
}

@page "/file-upload-2"
@using System.Net.Http.Headers
@using System.Text.Json
@using Microsoft.Extensions.Logging
@inject IHttpClientFactory ClientFactory
@inject ILogger<FileUpload2> Logger

<h1>File Upload Example 2</h1>

<p>
    This example requires a backend server API to function. For more information, 
    see the <em>Upload files to a server</em> section 
    of the <em>ASP.NET Core Blazor file uploads</em> article.
</p>

<p>
    <label>
        Upload up to @maxAllowedFiles files:
        <InputFile OnChange="OnInputFileChange" multiple />
    </label>
</p>

@if (files.Count > 0)
{
    <div class="card">
        <div class="card-body">
            <ul>
                @foreach (var file in files)
                {
                    <li>
                        File: @file.Name
                        <br>
                        @if (FileUpload(uploadResults, file.Name, Logger,
                           out var result))
                        {
                            <span>
                                Stored File Name: @result.StoredFileName
                            </span>
                        }
                        else
                        {
                            <span>
                                There was an error uploading the file
                                (Error: @result.ErrorCode).
                            </span>
                        }
                    </li>
                }
            </ul>
        </div>
    </div>
}

@code {
    private List<File> files = new();
    private List<UploadResult> uploadResults = new();
    private int maxAllowedFiles = 3;
    private bool shouldRender;

    protected override bool ShouldRender() => shouldRender;

    private async Task OnInputFileChange(InputFileChangeEventArgs e)
    {
        shouldRender = false;
        int maxFileSize = 1024 * 15;
        var upload = false;

        using var content = new MultipartFormDataContent();

        foreach (var file in e.GetMultipleFiles(maxAllowedFiles))
        {
            if (uploadResults.SingleOrDefault(
                f => f.FileName == file.Name) is null)
            {
                try
                {
                    files.Add(new() { Name = file.Name });

                    var stream = new LazyBrowserFileStream(file, maxFileSize);
                    var fileContent = new StreamContent(stream);
                    fileContent.Headers.ContentType = 
                        new MediaTypeHeaderValue(file.ContentType);

                    content.Add(
                        content: fileContent,
                        name: "\"files\"",
                        fileName: file.Name);

                    upload = true;
                }
                catch (Exception ex)
                {
                    Logger.LogInformation(
                        "{FileName} not uploaded (Err: 6): {Message}", 
                        file.Name, ex.Message);

                    uploadResults.Add(
                        new()
                        {
                            FileName = file.Name, 
                            ErrorCode = 6, 
                            Uploaded = false
                        });
                }
            }
        }

        if (upload)
        {
            var client = ClientFactory.CreateClient();

            var response = 
                await client.PostAsync("https://localhost:5001/Filesave", 
                content);

            if (response.IsSuccessStatusCode)
            {
                var options = new JsonSerializerOptions
                {
                    PropertyNameCaseInsensitive = true,
                };

                using var responseStream =
                    await response.Content.ReadAsStreamAsync();

                var newUploadResults = await JsonSerializer
                    .DeserializeAsync<IList<UploadResult>>(responseStream, options);

                if (newUploadResults is not null)
                {
                    uploadResults = uploadResults.Concat(newUploadResults).ToList();
                }
            }
        }

        shouldRender = true;
    }

    private static bool FileUpload(IList<UploadResult> uploadResults,
        string fileName, ILogger<FileUpload2> logger, out UploadResult result)
    {
        result = uploadResults.SingleOrDefault(f => f.FileName == fileName) ?? new();

        if (!result.Uploaded)
        {
            logger.LogInformation("{FileName} not uploaded (Err: 5)", fileName);
            result.ErrorCode = 5;
        }

        return result.Uploaded;
    }

    private class File
    {
        public string Name { get; set; }
    }
}

Jika komponen membatasi pengunggahan file ke satu file pada satu waktu atau jika komponen hanya mengadopsi penyajian sisi klien (CSR, InteractiveWebAssembly), komponen dapat menghindari penggunaan LazyBrowserFileStream dan menggunakan Stream. Berikut ini menunjukkan perubahan untuk FileUpload2 komponen:

- var stream = new LazyBrowserFileStream(file, maxFileSize);
- var fileContent = new StreamContent(stream);
+ var fileContent = new StreamContent(file.OpenReadStream(maxFileSize));

LazyBrowserFileStream Hapus kelas (LazyBrowserFileStream.cs), karena tidak digunakan.

Jika komponen membatasi pengunggahan file ke satu file sekaligus, komponen dapat menghindari penggunaan LazyBrowserFileStream dan menggunakan Stream. Berikut ini menunjukkan perubahan untuk FileUpload2 komponen:

- var stream = new LazyBrowserFileStream(file, maxFileSize);
- var fileContent = new StreamContent(stream);
+ var fileContent = new StreamContent(file.OpenReadStream(maxFileSize));

LazyBrowserFileStream Hapus kelas (LazyBrowserFileStream.cs), karena tidak digunakan.

Contoh ini mengadopsi streaming permintaan untuk browser berbasis Chromium (misalnya, Google Chrome atau Microsoft Edge) dengan protokol HTTP/2 dan HTTPS. Jika streaming permintaan tidak dapat digunakan, Blazor secara bertahap beralih ke Fetch API tanpa menggunakan streaming permintaan. Untuk informasi selengkapnya, lihat bagian batas baca dan unggahan ukuran file .

Dalam proyek server Blazor Web App, tambahkan IHttpClientFactory dan layanan terkait dalam file Program proyek:

builder.Services.AddHttpClient();

Layanan HttpClient harus ditambahkan ke proyek server karena komponen sisi klien sudah di-prarender di server. Jika Anda menonaktifkan pra-rendering untuk komponen berikut, Anda tidak perlu menyediakan layanan HttpClient dalam proyek server dan tidak perlu menambahkan baris tersebut ke proyek server.

Untuk informasi selengkapnya tentang menambahkan HttpClient layanan ke aplikasi ASP.NET Core, lihat Membuat permintaan HTTP menggunakan IHttpClientFactory di ASP.NET Core.

Proyek klien (.Client) dari Blazor Web App juga harus mendaftarkan sebuah HttpClient untuk permintaan HTTP POST ke pengontrol API web di backend. Konfirmasi atau tambahkan yang berikut ini ke file proyek Program klien:

builder.Services.AddScoped(sp => 
    new HttpClient { BaseAddress = new Uri(builder.HostEnvironment.BaseAddress) });

Contoh sebelumnya mengatur alamat dasar dengan builder.HostEnvironment.BaseAddress (IWebAssemblyHostEnvironment.BaseAddress), yang mendapatkan alamat dasar untuk aplikasi dan biasanya berasal dari <base> nilai tag href di halaman host. Jika Anda memanggil API web eksternal, atur URI ke alamat dasar API web.

Aplikasi Blazor WebAssembly mandiri yang mengunggah file ke API web di server terpisah menggunakan bernama HttpClient atau mengonfigurasi pendaftaran layanan HttpClient bawaan untuk mengarahkan ke titik akhir API web. Dalam contoh berikut di mana API web dihosting secara lokal di port 5001, alamat dasar https://localhost:5001:

builder.Services.AddScoped(sp => 
    new HttpClient { BaseAddress = new Uri("https://localhost:5001") });

Dalam Blazor Web App, tambahkan namespace Microsoft.AspNetCore.Components.WebAssembly.Http ke direktif komponen:

@using Microsoft.AspNetCore.Components.WebAssembly.Http

@page "/file-upload-2"
@using System.Linq
@using System.Net.Http.Headers
@using System.Net
@inject HttpClient Http
@inject ILogger<FileUpload2> Logger

<PageTitle>File Upload 2</PageTitle>

<h1>File Upload Example 2</h1>

<p>
    <label>
        Upload up to @maxAllowedFiles files:
        <InputFile OnChange="OnInputFileChange" multiple />
    </label>
</p>

@if (files.Count > 0)
{
    <div class="card">
        <div class="card-body">
            <ul>
                @foreach (var file in files)
                {
                    <li>
                        File: @file.Name
                        <br>
                        @if (FileUpload(uploadResults, file.Name, Logger,
                       out var result))
                        {
                            <span>
                                Stored File Name: @result.StoredFileName
                            </span>
                        }
                        else
                        {
                            <span>
                                There was an error uploading the file
                                (Error: @result.ErrorCode).
                            </span>
                        }
                    </li>
                }
            </ul>
        </div>
    </div>
}

@code {
    private List<File> files = new();
    private List<UploadResult> uploadResults = new();
    private int maxAllowedFiles = 3;
    private bool shouldRender;

    protected override bool ShouldRender() => shouldRender;

    private async Task OnInputFileChange(InputFileChangeEventArgs e)
    {
        shouldRender = false;
        long maxFileSize = 1024 * 15;
        var upload = false;

        using var content = new MultipartFormDataContent();

        foreach (var file in e.GetMultipleFiles(maxAllowedFiles))
        {
            if (uploadResults.SingleOrDefault(
                f => f.FileName == file.Name) is null)
            {
                try
                {
                    files.Add(new() { Name = file.Name });

                    var fileContent = new StreamContent(file.OpenReadStream(maxFileSize));

                    fileContent.Headers.ContentType =
                        new MediaTypeHeaderValue(file.ContentType);

                    content.Add(
                        content: fileContent,
                        name: "\"files\"",
                        fileName: file.Name);

                    upload = true;
                }
                catch (Exception ex)
                {
                    Logger.LogInformation(
                        "{FileName} not uploaded (Err: 6): {Message}",
                        file.Name, ex.Message);

                    uploadResults.Add(
                        new()
                        {
                            FileName = file.Name,
                            ErrorCode = 6,
                            Uploaded = false
                        });
                }
            }
        }

        if (upload)
        {
            var request = new HttpRequestMessage(HttpMethod.Post, "/Filesave");
            request.SetBrowserRequestStreamingEnabled(true);
            request.Content = content;

            var response = await Http.SendAsync(request);

            var newUploadResults = await response.Content
                .ReadFromJsonAsync<IList<UploadResult>>();

            if (newUploadResults is not null)
            {
                uploadResults = uploadResults.Concat(newUploadResults).ToList();
            }
        }

        shouldRender = true;
    }

    private static bool FileUpload(IList<UploadResult> uploadResults,
        string? fileName, ILogger<FileUpload2> logger, out UploadResult result)
    {
        result = uploadResults.SingleOrDefault(f => f.FileName == fileName) ?? new();

        if (!result.Uploaded)
        {
            logger.LogInformation("{FileName} not uploaded (Err: 5)", fileName);
            result.ErrorCode = 5;
        }

        return result.Uploaded;
    }

    private class File
    {
        public string? Name { get; set; }
    }
}

@page "/file-upload-2"
@using System.Linq
@using System.Net.Http.Headers
@inject HttpClient Http
@inject ILogger<FileUpload2> Logger

<PageTitle>File Upload 2</PageTitle>

<h1>File Upload Example 2</h1>

<p>
    <label>
        Upload up to @maxAllowedFiles files:
        <InputFile OnChange="OnInputFileChange" multiple />
    </label>
</p>

@if (files.Count > 0)
{
    <div class="card">
        <div class="card-body">
            <ul>
                @foreach (var file in files)
                {
                    <li>
                        File: @file.Name
                        <br>
                        @if (FileUpload(uploadResults, file.Name, Logger,
                           out var result))
                        {
                            <span>
                                Stored File Name: @result.StoredFileName
                            </span>
                        }
                        else
                        {
                            <span>
                                There was an error uploading the file
                                (Error: @result.ErrorCode).
                            </span>
                        }
                    </li>
                }
            </ul>
        </div>
    </div>
}

@code {
    private List<File> files = [];
    private List<UploadResult> uploadResults = [];
    private int maxAllowedFiles = 3;
    private bool shouldRender;

    protected override bool ShouldRender() => shouldRender;

    private async Task OnInputFileChange(InputFileChangeEventArgs e)
    {
        shouldRender = false;
        long maxFileSize = 1024 * 15;
        var upload = false;

        using var content = new MultipartFormDataContent();

        foreach (var file in e.GetMultipleFiles(maxAllowedFiles))
        {
            if (uploadResults.SingleOrDefault(
                f => f.FileName == file.Name) is null)
            {
                try
                {
                    files.Add(new() { Name = file.Name });

                    var fileContent = new StreamContent(file.OpenReadStream(maxFileSize));

                    fileContent.Headers.ContentType = 
                        new MediaTypeHeaderValue(file.ContentType);

                    content.Add(
                        content: fileContent,
                        name: "\"files\"",
                        fileName: file.Name);

                    upload = true;
                }
                catch (Exception ex)
                {
                    Logger.LogInformation(
                        "{FileName} not uploaded (Err: 6): {Message}", 
                        file.Name, ex.Message);

                    uploadResults.Add(
                        new()
                        {
                            FileName = file.Name, 
                            ErrorCode = 6, 
                            Uploaded = false
                        });
                }
            }
        }

        if (upload)
        {
            var response = await Http.PostAsync("/Filesave", content);

            var newUploadResults = await response.Content
                .ReadFromJsonAsync<IList<UploadResult>>();

            if (newUploadResults is not null)
            {
                uploadResults = uploadResults.Concat(newUploadResults).ToList();
            }
        }

        shouldRender = true;
    }

    private static bool FileUpload(IList<UploadResult> uploadResults,
        string? fileName, ILogger<FileUpload2> logger, out UploadResult result)
    {
        result = uploadResults.SingleOrDefault(f => f.FileName == fileName) ?? new();

        if (!result.Uploaded)
        {
            logger.LogInformation("{FileName} not uploaded (Err: 5)", fileName);
            result.ErrorCode = 5;
        }

        return result.Uploaded;
    }

    private class File
    {
        public string? Name { get; set; }
    }
}

@page "/file-upload-2"
@using System.Linq
@using System.Net.Http.Headers
@using Microsoft.Extensions.Logging
@inject HttpClient Http
@inject ILogger<FileUpload2> Logger

<h1>Upload Files</h1>

<p>
    <label>
        Upload up to @maxAllowedFiles files:
        <InputFile OnChange="OnInputFileChange" multiple />
    </label>
</p>

@if (files.Count > 0)
{
    <div class="card">
        <div class="card-body">
            <ul>
                @foreach (var file in files)
                {
                    <li>
                        File: @file.Name
                        <br>
                        @if (FileUpload(uploadResults, file.Name, Logger,
                           out var result))
                        {
                            <span>
                                Stored File Name: @result.StoredFileName
                            </span>
                        }
                        else
                        {
                            <span>
                                There was an error uploading the file
                                (Error: @result.ErrorCode).
                            </span>
                        }
                    </li>
                }
            </ul>
        </div>
    </div>
}

@code {
    private List<File> files = new();
    private List<UploadResult> uploadResults = new();
    private int maxAllowedFiles = 3;
    private bool shouldRender;

    protected override bool ShouldRender() => shouldRender;

    private async Task OnInputFileChange(InputFileChangeEventArgs e)
    {
        shouldRender = false;
        long maxFileSize = 1024 * 15;
        var upload = false;

        using var content = new MultipartFormDataContent();

        foreach (var file in e.GetMultipleFiles(maxAllowedFiles))
        {
            if (uploadResults.SingleOrDefault(
                f => f.FileName == file.Name) is null)
            {
                try
                {
                    files.Add(new() { Name = file.Name });

                    var fileContent = new StreamContent(file.OpenReadStream(maxFileSize));

                    fileContent.Headers.ContentType = 
                        new MediaTypeHeaderValue(file.ContentType);

                    content.Add(
                        content: fileContent,
                        name: "\"files\"",
                        fileName: file.Name);

                    upload = true;
                }
                catch (Exception ex)
                {
                    Logger.LogInformation(
                        "{FileName} not uploaded (Err: 6): {Message}", 
                        file.Name, ex.Message);

                    uploadResults.Add(
                        new()
                        {
                            FileName = file.Name, 
                            ErrorCode = 6, 
                            Uploaded = false
                        });
                }
            }
        }

        if (upload)
        {
            var response = await Http.PostAsync("/Filesave", content);

            var newUploadResults = await response.Content
                .ReadFromJsonAsync<IList<UploadResult>>();

            if (newUploadResults is not null)
            {
                uploadResults = uploadResults.Concat(newUploadResults).ToList();
            }
        }

        shouldRender = true;
    }

    private static bool FileUpload(IList<UploadResult> uploadResults,
        string? fileName, ILogger<FileUpload2> logger, out UploadResult result)
    {
        result = uploadResults.SingleOrDefault(f => f.FileName == fileName) ?? new();

        if (!result.Uploaded)
        {
            logger.LogInformation("{FileName} not uploaded (Err: 5)", fileName);
            result.ErrorCode = 5;
        }

        return result.Uploaded;
    }

    private class File
    {
        public string? Name { get; set; }
    }
}

@page "/file-upload-2"
@using System.Linq
@using System.Net.Http.Headers
@using Microsoft.Extensions.Logging
@inject HttpClient Http
@inject ILogger<FileUpload2> Logger

<h1>Upload Files</h1>

<p>
    <label>
        Upload up to @maxAllowedFiles files:
        <InputFile OnChange="OnInputFileChange" multiple />
    </label>
</p>

@if (files.Count > 0)
{
    <div class="card">
        <div class="card-body">
            <ul>
                @foreach (var file in files)
                {
                    <li>
                        File: @file.Name
                        <br>
                        @if (FileUpload(uploadResults, file.Name, Logger,
                           out var result))
                        {
                            <span>
                                Stored File Name: @result.StoredFileName
                            </span>
                        }
                        else
                        {
                            <span>
                                There was an error uploading the file
                                (Error: @result.ErrorCode).
                            </span>
                        }
                    </li>
                }
            </ul>
        </div>
    </div>
}

@code {
    private List<File> files = new();
    private List<UploadResult> uploadResults = new();
    private int maxAllowedFiles = 3;
    private bool shouldRender;

    protected override bool ShouldRender() => shouldRender;

    private async Task OnInputFileChange(InputFileChangeEventArgs e)
    {
        shouldRender = false;
        long maxFileSize = 1024 * 15;
        var upload = false;

        using var content = new MultipartFormDataContent();

        foreach (var file in e.GetMultipleFiles(maxAllowedFiles))
        {
            if (uploadResults.SingleOrDefault(
                f => f.FileName == file.Name) is null)
            {
                try
                {
                    files.Add(new() { Name = file.Name });

                    var fileContent = new StreamContent(file.OpenReadStream(maxFileSize));

                    fileContent.Headers.ContentType = 
                        new MediaTypeHeaderValue(file.ContentType);

                    content.Add(
                        content: fileContent,
                        name: "\"files\"",
                        fileName: file.Name);

                    upload = true;
                }
                catch (Exception ex)
                {
                    Logger.LogInformation(
                        "{FileName} not uploaded (Err: 6): {Message}", 
                        file.Name, ex.Message);

                    uploadResults.Add(
                        new()
                        {
                            FileName = file.Name, 
                            ErrorCode = 6, 
                            Uploaded = false
                        });
                }
            }
        }

        if (upload)
        {
            var response = await Http.PostAsync("/Filesave", content);

            var newUploadResults = await response.Content
                .ReadFromJsonAsync<IList<UploadResult>>();

            if (newUploadResults is not null)
            {
                uploadResults = uploadResults.Concat(newUploadResults).ToList();
            }
        }

        shouldRender = true;
    }

    private static bool FileUpload(IList<UploadResult> uploadResults,
        string? fileName, ILogger<FileUpload2> logger, out UploadResult result)
    {
        result = uploadResults.SingleOrDefault(f => f.FileName == fileName) ?? new();

        if (!result.Uploaded)
        {
            logger.LogInformation("{FileName} not uploaded (Err: 5)", fileName);
            result.ErrorCode = 5;
        }

        return result.Uploaded;
    }

    private class File
    {
        public string? Name { get; set; }
    }
}

@page "/file-upload-2"
@using System.Linq
@using System.Net.Http.Headers
@using Microsoft.Extensions.Logging
@inject HttpClient Http
@inject ILogger<FileUpload2> Logger

<h1>Upload Files</h1>

<p>
    <label>
        Upload up to @maxAllowedFiles files:
        <InputFile OnChange="OnInputFileChange" multiple />
    </label>
</p>

@if (files.Count > 0)
{
    <div class="card">
        <div class="card-body">
            <ul>
                @foreach (var file in files)
                {
                    <li>
                        File: @file.Name
                        <br>
                        @if (FileUpload(uploadResults, file.Name, Logger,
                           out var result))
                        {
                            <span>
                                Stored File Name: @result.StoredFileName
                            </span>
                        }
                        else
                        {
                            <span>
                                There was an error uploading the file
                                (Error: @result.ErrorCode).
                            </span>
                        }
                    </li>
                }
            </ul>
        </div>
    </div>
}

@code {
    private List<File> files = new();
    private List<UploadResult> uploadResults = new();
    private int maxAllowedFiles = 3;
    private bool shouldRender;

    protected override bool ShouldRender() => shouldRender;

    private async Task OnInputFileChange(InputFileChangeEventArgs e)
    {
        shouldRender = false;
        long maxFileSize = 1024 * 15;
        var upload = false;

        using var content = new MultipartFormDataContent();

        foreach (var file in e.GetMultipleFiles(maxAllowedFiles))
        {
            if (uploadResults.SingleOrDefault(
                f => f.FileName == file.Name) is null)
            {
                try
                {
                    files.Add(new() { Name = file.Name });

                    var fileContent = new StreamContent(file.OpenReadStream(maxFileSize));

                    fileContent.Headers.ContentType = 
                        new MediaTypeHeaderValue(file.ContentType);

                    content.Add(
                        content: fileContent,
                        name: "\"files\"",
                        fileName: file.Name);

                    upload = true;
                }
                catch (Exception ex)
                {
                    Logger.LogInformation(
                        "{FileName} not uploaded (Err: 6): {Message}", 
                        file.Name, ex.Message);

                    uploadResults.Add(
                        new()
                        {
                            FileName = file.Name, 
                            ErrorCode = 6, 
                            Uploaded = false
                        });
                }
            }
        }

        if (upload)
        {
            var response = await Http.PostAsync("/Filesave", content);

            var newUploadResults = await response.Content
                .ReadFromJsonAsync<IList<UploadResult>>();

            uploadResults = uploadResults.Concat(newUploadResults).ToList();
        }

        shouldRender = true;
    }

    private static bool FileUpload(IList<UploadResult> uploadResults,
        string fileName, ILogger<FileUpload2> logger, out UploadResult result)
    {
        result = uploadResults.SingleOrDefault(f => f.FileName == fileName);

        if (result is null)
        {
            logger.LogInformation("{FileName} not uploaded (Err: 5)", fileName);
            result = new();
            result.ErrorCode = 5;
        }

        return result.Uploaded;
    }

    private class File
    {
        public string Name { get; set; }
    }
}

Konfigurasi Permintaan Lintas Asal (CORS) di server diperlukan untuk meminta streaming ketika server dihosting di asal yang berbeda, dan permintaan preflight selalu dibuat oleh klien. Dalam konfigurasi layanan file Program server (proyek server Blazor Web App atau API web server backend dari aplikasi Blazor WebAssembly), kebijakan CORS default berikut cocok untuk pengujian dengan contoh dalam artikel ini. Klien membuat permintaan lokal dari port 5003. Ubah nomor port agar sesuai dengan port aplikasi klien yang Anda gunakan:

Konfigurasikan Permintaan Lintas Asal (CORS) di server. Dalam konfigurasi layanan file Program server (proyek server Blazor Web App atau API web server backend dari aplikasi Blazor WebAssembly), kebijakan CORS default berikut cocok untuk pengujian dengan contoh dalam artikel ini. Klien membuat permintaan lokal dari port 5003. Ubah nomor port agar sesuai dengan port aplikasi klien yang Anda gunakan:

Konfigurasikan Permintaan Lintas Asal (CORS) di server. Dalam konfigurasi layanan pada file Program API web server backend, kebijakan CORS default berikut cocok untuk pengujian dengan contoh dalam artikel ini. Klien membuat permintaan lokal dari port 5003. Ubah nomor port agar sesuai dengan port aplikasi klien yang Anda gunakan:

Konfigurasikan ukuran isi permintaan maksimum server dan batas panjang isi multipisah jika batasan membatasi ukuran unggahan.

Untuk server Kestrel, atur MaxRequestBodySize (default: 30.000.000 byte) dan FormOptions.MultipartBodyLengthLimit (default: 134.217.728 byte). Atur variabel maxFileSize dalam komponen dan pengontrol ke nilai yang sama.

Dalam konfigurasi Kestrel file Program berikut (proyek server Blazor Web App atau API web server backend dari aplikasi Blazor WebAssembly), tempat penampung {LIMIT} adalah batas dalam byte:

using Microsoft.AspNetCore.Http.Features;

...

builder.WebHost.ConfigureKestrel(serverOptions =>
{
    serverOptions.Limits.MaxRequestBodySize = {LIMIT};
});

builder.Services.Configure<FormOptions>(options =>
{
    options.MultipartBodyLengthLimit = {LIMIT};
});

@page "/file-upload-3"
@inject ILogger<FileUpload3> Logger
@inject IWebHostEnvironment Environment

<PageTitle>File Upload 3</PageTitle>

<h1>File Upload Example 3</h1>

<p>
    <label>
        Max file size:
        <input type="number" @bind="maxFileSize" />
    </label>
</p>

<p>
    <label>
        Max allowed files:
        <input type="number" @bind="maxAllowedFiles" />
    </label>
</p>

<p>
    <label>
        Upload up to @maxAllowedFiles of up to @maxFileSize bytes:
        <InputFile OnChange="LoadFiles" multiple />
    </label>
</p>

@if (isLoading)
{
    <p>Progress: @string.Format("{0:P0}", progressPercent)</p>
}
else
{
    <ul>
        @foreach (var file in loadedFiles)
        {
            <li>
                <ul>
                    <li>Name: @file.Name</li>
                    <li>Last modified: @file.LastModified.ToString()</li>
                    <li>Size (bytes): @file.Size</li>
                    <li>Content type: @file.ContentType</li>
                </ul>
            </li>
        }
    </ul>
}

@code {
    private List<IBrowserFile> loadedFiles = [];
    private long maxFileSize = 1024 * 15;
    private int maxAllowedFiles = 3;
    private bool isLoading;
    private decimal progressPercent;

    private async Task LoadFiles(InputFileChangeEventArgs e)
    {
        isLoading = true;
        loadedFiles.Clear();
        progressPercent = 0;

        foreach (var file in e.GetMultipleFiles(maxAllowedFiles))
        {
            try
            {
                var trustedFileName = Path.GetRandomFileName();
                var path = Path.Combine(Environment.ContentRootPath,
                    Environment.EnvironmentName, "unsafe_uploads", trustedFileName);

                await using FileStream writeStream = new(path, FileMode.Create);
                using var readStream = file.OpenReadStream(maxFileSize);
                var bytesRead = 0;
                var totalRead = 0;
                var buffer = new byte[1024 * 10];

                while ((bytesRead = await readStream.ReadAsync(buffer)) != 0)
                {
                    totalRead += bytesRead;
                    await writeStream.WriteAsync(buffer, 0, bytesRead);
                    progressPercent = Decimal.Divide(totalRead, file.Size);
                    StateHasChanged();
                }

                loadedFiles.Add(file);

                Logger.LogInformation(
                    "Unsafe Filename: {UnsafeFilename} File saved: {Filename}",
                    file.Name, trustedFileName);
            }
            catch (Exception ex)
            {
                Logger.LogError("File: {FileName} Error: {Error}", 
                    file.Name, ex.Message);
            }
        }

        isLoading = false;
    }
}

@page "/file-upload-3"
@using System 
@using System.IO
@using Microsoft.AspNetCore.Hosting
@using Microsoft.Extensions.Logging
@inject ILogger<FileUpload3> Logger
@inject IWebHostEnvironment Environment

<h3>Upload Files</h3>

<p>
    <label>
        Max file size:
        <input type="number" @bind="maxFileSize" />
    </label>
</p>

<p>
    <label>
        Max allowed files:
        <input type="number" @bind="maxAllowedFiles" />
    </label>
</p>

<p>
    <label>
        Upload up to @maxAllowedFiles of up to @maxFileSize bytes:
        <InputFile OnChange="LoadFiles" multiple />
    </label>
</p>

@if (isLoading)
{
    <p>Progress: @string.Format("{0:P0}", progressPercent)</p>
}
else
{
    <ul>
        @foreach (var file in loadedFiles)
        {
            <li>
                <ul>
                    <li>Name: @file.Name</li>
                    <li>Last modified: @file.LastModified.ToString()</li>
                    <li>Size (bytes): @file.Size</li>
                    <li>Content type: @file.ContentType</li>
                </ul>
            </li>
        }
    </ul>
}

@code {
    private List<IBrowserFile> loadedFiles = new();
    private long maxFileSize = 1024 * 15;
    private int maxAllowedFiles = 3;
    private bool isLoading;
    private decimal progressPercent;

    private async Task LoadFiles(InputFileChangeEventArgs e)
    {
        isLoading = true;
        loadedFiles.Clear();
        progressPercent = 0;

        foreach (var file in e.GetMultipleFiles(maxAllowedFiles))
        {
            try
            {
                var trustedFileName = Path.GetRandomFileName();
                var path = Path.Combine(Environment.ContentRootPath,
                    Environment.EnvironmentName, "unsafe_uploads", trustedFileName);

                await using FileStream writeStream = new(path, FileMode.Create);
                using var readStream = file.OpenReadStream(maxFileSize);
                var bytesRead = 0;
                var totalRead = 0;
                var buffer = new byte[1024 * 10];

                while ((bytesRead = await readStream.ReadAsync(buffer)) != 0)
                {
                    totalRead += bytesRead;

                    await writeStream.WriteAsync(buffer, 0, bytesRead);

                    progressPercent = Decimal.Divide(totalRead, file.Size);

                    StateHasChanged();
                }

                loadedFiles.Add(file);
            }
            catch (Exception ex)
            {
                Logger.LogError("File: {FileName} Error: {Error}", 
                    file.Name, ex.Message);
            }
        }

        isLoading = false;
    }
}

@page "/file-upload-3"
@using System 
@using System.IO
@using Microsoft.AspNetCore.Hosting
@using Microsoft.Extensions.Logging
@inject ILogger<FileUpload3> Logger
@inject IWebHostEnvironment Environment

<h3>Upload Files</h3>

<p>
    <label>
        Max file size:
        <input type="number" @bind="maxFileSize" />
    </label>
</p>

<p>
    <label>
        Max allowed files:
        <input type="number" @bind="maxAllowedFiles" />
    </label>
</p>

<p>
    <label>
        Upload up to @maxAllowedFiles of up to @maxFileSize bytes:
        <InputFile OnChange="LoadFiles" multiple />
    </label>
</p>

@if (isLoading)
{
    <p>Progress: @string.Format("{0:P0}", progressPercent)</p>
}
else
{
    <ul>
        @foreach (var file in loadedFiles)
        {
            <li>
                <ul>
                    <li>Name: @file.Name</li>
                    <li>Last modified: @file.LastModified.ToString()</li>
                    <li>Size (bytes): @file.Size</li>
                    <li>Content type: @file.ContentType</li>
                </ul>
            </li>
        }
    </ul>
}

@code {
    private List<IBrowserFile> loadedFiles = new();
    private long maxFileSize = 1024 * 15;
    private int maxAllowedFiles = 3;
    private bool isLoading;
    private decimal progressPercent;

    private async Task LoadFiles(InputFileChangeEventArgs e)
    {
        isLoading = true;
        loadedFiles.Clear();
        progressPercent = 0;

        foreach (var file in e.GetMultipleFiles(maxAllowedFiles))
        {
            try
            {
                var trustedFileName = Path.GetRandomFileName();
                var path = Path.Combine(Environment.ContentRootPath,
                    Environment.EnvironmentName, "unsafe_uploads", trustedFileName);

                await using FileStream writeStream = new(path, FileMode.Create);
                using var readStream = file.OpenReadStream(maxFileSize);
                var bytesRead = 0;
                var totalRead = 0;
                var buffer = new byte[1024 * 10];

                while ((bytesRead = await readStream.ReadAsync(buffer)) != 0)
                {
                    totalRead += bytesRead;

                    await writeStream.WriteAsync(buffer, 0, bytesRead);

                    progressPercent = Decimal.Divide(totalRead, file.Size);

                    StateHasChanged();
                }

                loadedFiles.Add(file);
            }
            catch (Exception ex)
            {
                Logger.LogError("File: {Filename} Error: {Error}", 
                    file.Name, ex.Message);
            }
        }

        isLoading = false;
    }
}

@page "/file-upload-3"
@using System 
@using System.IO
@using Microsoft.AspNetCore.Hosting
@using Microsoft.Extensions.Logging
@inject ILogger<FileUpload3> Logger
@inject IWebHostEnvironment Environment

<h3>Upload Files</h3>

<p>
    <label>
        Max file size:
        <input type="number" @bind="maxFileSize" />
    </label>
</p>

<p>
    <label>
        Max allowed files:
        <input type="number" @bind="maxAllowedFiles" />
    </label>
</p>

<p>
    <label>
        Upload up to @maxAllowedFiles of up to @maxFileSize bytes:
        <InputFile OnChange="LoadFiles" multiple />
    </label>
</p>

@if (isLoading)
{
    <p>Progress: @string.Format("{0:P0}", progressPercent)</p>
}
else
{
    <ul>
        @foreach (var file in loadedFiles)
        {
            <li>
                <ul>
                    <li>Name: @file.Name</li>
                    <li>Last modified: @file.LastModified.ToString()</li>
                    <li>Size (bytes): @file.Size</li>
                    <li>Content type: @file.ContentType</li>
                </ul>
            </li>
        }
    </ul>
}

@code {
    private List<IBrowserFile> loadedFiles = new();
    private long maxFileSize = 1024 * 15;
    private int maxAllowedFiles = 3;
    private bool isLoading;
    private decimal progressPercent;

    private async Task LoadFiles(InputFileChangeEventArgs e)
    {
        isLoading = true;
        loadedFiles.Clear();
        progressPercent = 0;

        foreach (var file in e.GetMultipleFiles(maxAllowedFiles))
        {
            try
            {
                var trustedFileName = Path.GetRandomFileName();
                var path = Path.Combine(Environment.ContentRootPath,
                    Environment.EnvironmentName, "unsafe_uploads", trustedFileName);

                await using FileStream writeStream = new(path, FileMode.Create);
                using var readStream = file.OpenReadStream(maxFileSize);
                var bytesRead = 0;
                var totalRead = 0;
                var buffer = new byte[1024 * 10];

                while ((bytesRead = await readStream.ReadAsync(buffer)) != 0)
                {
                    totalRead += bytesRead;

                    await writeStream.WriteAsync(buffer, 0, bytesRead);

                    progressPercent = Decimal.Divide(totalRead, file.Size);

                    StateHasChanged();
                }

                loadedFiles.Add(file);
            }
            catch (Exception ex)
            {
                Logger.LogError("File: {Filename} Error: {Error}", 
                    file.Name, ex.Message);
            }
        }

        isLoading = false;
    }
}

RemoteBrowserFileStreamOptions memungkinkan konfigurasi karakteristik pengunggahan file.

Unggah pratinjau gambar

Untuk pratinjau gambar saat mengunggah, mulailah dengan menambahkan sebuah komponen InputFile dengan referensi komponen dan penangan OnChange.

<InputFile @ref="inputFile" OnChange="ShowPreview" />

Tambahkan elemen gambar dengan elemen referensi , yang berfungsi sebagai tempat penampung untuk pratinjau gambar:

<img @ref="previewImageElem" />

Tambahkan referensi terkait:

@code {
    private InputFile? inputFile;
    private ElementReference previewImageElem;
}

Di JavaScript, tambahkan fungsi yang disebut dengan HTML input dan img elemen yang melakukan hal berikut:

• Mengekstrak file terpilih.
• Membuat URL objek dengan createObjectURL.
• Mengatur pendengar acara untuk mencabut URL objek dengan revokeObjectURL setelah gambar dimuat, agar memori tidak bocor.
• img Mengatur sumber elemen untuk menampilkan gambar.

window.previewImage = (inputElem, imgElem) => {
  const url = URL.createObjectURL(inputElem.files[0]);
  imgElem.addEventListener('load', () => URL.revokeObjectURL(url), { once: true });
  imgElem.src = url;
}

Terakhir, gunakan IJSRuntime yang disuntikkan untuk menambahkan handler OnChange yang memanggil fungsi JavaScript.

@inject IJSRuntime JS

...

@code {
    ...

    private async Task ShowPreview() => await JS.InvokeVoidAsync(
        "previewImage", inputFile!.Element, previewImageElem);
}

Contoh sebelumnya adalah untuk mengunggah satu gambar. Pendekatan dapat diperluas untuk mendukung multiple gambar.

Komponen berikut FileUpload4 menunjukkan contoh lengkapnya.

FileUpload4.razor:

@page "/file-upload-4"
@inject IJSRuntime JS

<h1>File Upload Example</h1>

<InputFile @ref="inputFile" OnChange="ShowPreview" />

<img style="max-width:200px;max-height:200px" @ref="previewImageElem" />

@code {
    private InputFile? inputFile;
    private ElementReference previewImageElem;

    private async Task ShowPreview() => await JS.InvokeVoidAsync(
        "previewImage", inputFile!.Element, previewImageElem);
}

@page "/file-upload-4"
@inject IJSRuntime JS

<h1>File Upload Example</h1>

<InputFile @ref="inputFile" OnChange="ShowPreview" />

<img style="max-width:200px;max-height:200px" @ref="previewImageElem" />

@code {
    private InputFile? inputFile;
    private ElementReference previewImageElem;

    private async Task ShowPreview() => await JS.InvokeVoidAsync(
        "previewImage", inputFile!.Element, previewImageElem);
}

• unduhan file ASP.NET Core Blazor
• Mengunggah file di ASP.NET Core
• Ikhtisar Formulir ASP.NET CoreBlazor
• Blazor repositori contoh GitHub (dotnet/blazor-samples) (cara mengunduh)

• Mengunggah file di ASP.NET Core
• Ikhtisar formulir ASP.NET CoreBlazor
• Blazor repositori GitHub sampel (dotnet/blazor-samples) (cara mengunduh)