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DWM_SYSTEMBACKDROP_TYPE enumeration (dwmapi.h)

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Flags for specifying the system-drawn backdrop material of a window, including behind the non-client area.

Syntax

typedef enum DWM_SYSTEMBACKDROP_TYPE {
  DWMSBT_AUTO,
  DWMSBT_NONE,
  DWMSBT_MAINWINDOW,
  DWMSBT_TRANSIENTWINDOW,
  DWMSBT_TABBEDWINDOW
} ;

Constants

 
DWMSBT_AUTO
The default. Let the Desktop Window Manager (DWM) automatically decide the system-drawn backdrop material for this window. This applies the backdrop material just behind the default Win32 title bar. This behavior attempts to preserve maximum backwards compatibility. For this reason, the DWM might also decide to draw no backdrop material at all based on internal heuristics.

If drawing the backdrop material behind the entire window is required, choose one of the other more specific values of this enum as appropriate.
DWMSBT_NONE
Don't draw any system backdrop.
DWMSBT_MAINWINDOW
Draw the backdrop material effect corresponding to a long-lived window behind the entire window bounds.

For Windows 11, this corresponds to Mica in its default variant. The material effect might change with future Windows releases. For more info about Mica, see Mica.
DWMSBT_TRANSIENTWINDOW
Draw the backdrop material effect corresponding to a transient window behind the entire window bounds.

For Windows 11, this corresponds to Desktop Acrylic, also known as Background Acrylic, in its brightest variant. The material effect might change with future Windows releases. For more info about Desktop Acrylic, see Acrylic.
DWMSBT_TABBEDWINDOW
Draw the backdrop material effect corresponding to a window with a tabbed title bar behind the entire window bounds.

For Windows 11, this corresponds to Mica in its alternate variant (Mica Alt). The material might change with future releases of Windows. For more info about Mica Alt, see Layering with Mica Alt.

Requirements

Requirement Value
Minimum supported client Windows 11 Build 22621
Header dwmapi.h