XmlWriter.WriteBase64(Byte[], Int32, Int32) 方法

public:
 abstract void WriteBase64(cli::array <System::Byte> ^ buffer, int index, int count);

public abstract void WriteBase64(byte[] buffer, int index, int count);

abstract member WriteBase64 : byte[] * int * int -> unit

Public MustOverride Sub WriteBase64 (buffer As Byte(), index As Integer, count As Integer)

下列範例會 WriteBase64 使用 方法來寫入 Base64 資料。 資料 Base64 會內嵌在 元素 <image> 內。

public static void Base64EncodeImageFile() {

  int bufferSize = 1000;
  byte[] buffer = new byte[bufferSize];
  int readBytes = 0;
    
  using (XmlWriter writer = XmlWriter.Create("output.xml")) {

       FileStream inputFile = new FileStream(@"C:\artFiles\sunset.jpg",
                                                                    FileMode.OpenOrCreate, FileAccess.Read, FileShare.Read);
       writer.WriteStartDocument();
       writer.WriteStartElement("image");
       BinaryReader br = new BinaryReader(inputFile);
       Console.WriteLine("\r\nWriting Base64 data...");

       do {
          readBytes = br.Read(buffer, 0, bufferSize);
          writer.WriteBase64(buffer, 0, readBytes);
       } while (bufferSize <= readBytes);
       br.Close();
        
    writer.WriteEndElement();// </image>
    writer.WriteEndDocument();
  }
}

Public Shared Sub Base64EncodeImageFile() 
    
    Dim bufferSize As Integer = 1000
    Dim buffer(bufferSize) As Byte
    Dim readBytes As Integer = 0
    
    Using writer As XmlWriter = XmlWriter.Create("output.xml")

            Dim inputFile As New FileStream("C:\artFiles\sunset.jpg", FileMode.OpenOrCreate, FileAccess.Read, FileShare.Read)
            writer.WriteStartDocument()
            writer.WriteStartElement("image")
            Dim br As New BinaryReader(inputFile)
            Console.WriteLine(vbCr + vbLf + "Writing Base64 data...")
            
            Do
                readBytes = br.Read(buffer, 0, bufferSize)
                writer.WriteBase64(buffer, 0, readBytes)
            Loop While bufferSize <= readBytes
            br.Close()
        
        writer.WriteEndElement() ' </image>
        writer.WriteEndDocument()

    End Using
 
End Sub

例如，位元組緩衝區可能包含 GIF 影像的二進位內容。 這顯然不是有效的 XML。 編碼 Base64 是設計來代表由 65 個 US-ASCII 字元組成的文字格式的任意位元組序列 ([A-Za-z0-9+/=]) ，其中每個字元都會編碼 6 位的二進位資料。 如需詳細資訊，請參閱要求批註網站中的 RFC) 1521 (批註要求。

如需這個方法的非同步版本，請參閱 WriteBase64Async 。