DWM_BLURBEHIND structure (dwmapi.h)

Specifies Desktop Window Manager (DWM) blur-behind properties. Used by the DwmEnableBlurBehindWindow function.

typedef struct _DWM_BLURBEHIND {
  DWORD dwFlags;
  BOOL  fEnable;
  HRGN  hRgnBlur;
  BOOL  fTransitionOnMaximized;
} DWM_BLURBEHIND, *PDWM_BLURBEHIND;

dwFlags

A bitwise combination of DWM Blur Behind constant values that indicates which of the members of this structure have been set.

fEnable

TRUE to register the window handle to DWM blur behind; FALSE to unregister the window handle from DWM blur behind.

hRgnBlur

The region within the client area where the blur behind will be applied. A NULL value will apply the blur behind the entire client area.

fTransitionOnMaximized

TRUE if the window's colorization should transition to match the maximized windows; otherwise, FALSE.