DWMWINDOWATTRIBUTE Enumeration

Flags used by the DwmGetWindowAttribute and DwmSetWindowAttribute functions to specify window attributes for Desktop Window Manager (DWM) non-client rendering. For programming guidance, and code examples, see Controlling non-client region rendering.

Syntax

typedef enum DWMWINDOWATTRIBUTE {
  DWMWA_NCRENDERING_ENABLED,
  DWMWA_NCRENDERING_POLICY,
  DWMWA_TRANSITIONS_FORCEDISABLED,
  DWMWA_ALLOW_NCPAINT,
  DWMWA_CAPTION_BUTTON_BOUNDS,
  DWMWA_NONCLIENT_RTL_LAYOUT,
  DWMWA_FORCE_ICONIC_REPRESENTATION,
  DWMWA_FLIP3D_POLICY,
  DWMWA_EXTENDED_FRAME_BOUNDS,
  DWMWA_HAS_ICONIC_BITMAP,
  DWMWA_DISALLOW_PEEK,
  DWMWA_EXCLUDED_FROM_PEEK,
  DWMWA_CLOAK,
  DWMWA_CLOAKED,
  DWMWA_FREEZE_REPRESENTATION,
  DWMWA_LAST
} ;

Constants

DWMWA_NCRENDERING_ENABLED Use with DwmGetWindowAttribute. Discovers whether non-client rendering is enabled. The retrieved value is of type BOOL. TRUE if non-client rendering is enabled; otherwise, FALSE.
DWMWA_NCRENDERING_POLICY Use with DwmSetWindowAttribute. Sets the non-client rendering policy. The pvAttribute parameter points to a value from the DWMNCRENDERINGPOLICY enumeration.
DWMWA_TRANSITIONS_FORCEDISABLED Use with DwmSetWindowAttribute. Enables or forcibly disables DWM transitions. The pvAttribute parameter points to a value of type BOOL. TRUE to disable transitions, or FALSE to enable transitions.
DWMWA_ALLOW_NCPAINT Use with DwmSetWindowAttribute. Enables content rendered in the non-client area to be visible on the frame drawn by DWM. The pvAttribute parameter points to a value of type BOOL. TRUE to enable content rendered in the non-client area to be visible on the frame; otherwise, FALSE.
DWMWA_CAPTION_BUTTON_BOUNDS Use with DwmGetWindowAttribute. Retrieves the bounds of the caption button area in the window-relative space. The retrieved value is of type RECT. If the window is minimized or otherwise not visible to the user, then the value of the **RECT** retrieved is undefined. You should check whether the retrieved **RECT** contains a boundary that you can work with, and if it doesn't then you can conclude that the window is minimized or otherwise not visible.
DWMWA_NONCLIENT_RTL_LAYOUT Use with DwmSetWindowAttribute. Specifies whether non-client content is right-to-left (RTL) mirrored. The pvAttribute parameter points to a value of type BOOL. TRUE if the non-client content is right-to-left (RTL) mirrored; otherwise, FALSE.
DWMWA_FORCE_ICONIC_REPRESENTATION Use with DwmSetWindowAttribute. Forces the window to display an iconic thumbnail or peek representation (a static bitmap), even if a live or snapshot representation of the window is available. This value is normally set during a window's creation, and not changed throughout the window's lifetime. Some scenarios, however, might require the value to change over time. The pvAttribute parameter points to a value of type BOOL. TRUE to require a iconic thumbnail or peek representation; otherwise, FALSE.
DWMWA_FLIP3D_POLICY Use with DwmSetWindowAttribute. Sets how Flip3D treats the window. The pvAttribute parameter points to a value from the DWMFLIP3DWINDOWPOLICY enumeration.
DWMWA_EXTENDED_FRAME_BOUNDS Use with DwmGetWindowAttribute. Retrieves the extended frame bounds rectangle in screen space. The retrieved value is of type RECT.
DWMWA_HAS_ICONIC_BITMAP Use with DwmSetWindowAttribute. The window will provide a bitmap for use by DWM as an iconic thumbnail or peek representation (a static bitmap) for the window. DWMWA_HAS_ICONIC_BITMAP can be specified with DWMWA_FORCE_ICONIC_REPRESENTATION. DWMWA_HAS_ICONIC_BITMAP normally is set during a window's creation and not changed throughout the window's lifetime. Some scenarios, however, might require the value to change over time. The pvAttribute parameter points to a value of type BOOL. TRUE to inform DWM that the window will provide an iconic thumbnail or peek representation; otherwise, FALSE.

Windows Vista and earlier: This value is not supported.

DWMWA_DISALLOW_PEEK Use with DwmSetWindowAttribute. Do not show peek preview for the window. The peek view shows a full-sized preview of the window when the mouse hovers over the window's thumbnail in the taskbar. If this attribute is set, hovering the mouse pointer over the window's thumbnail dismisses peek (in case another window in the group has a peek preview showing). The pvAttribute parameter points to a value of type BOOL. TRUE to prevent peek functionality, or FALSE to allow it.

Windows Vista and earlier: This value is not supported.

DWMWA_EXCLUDED_FROM_PEEK Use with DwmSetWindowAttribute. Prevents a window from fading to a glass sheet when peek is invoked. The pvAttribute parameter points to a value of type BOOL. TRUE to prevent the window from fading during another window's peek, or FALSE for normal behavior.

Windows Vista and earlier: This value is not supported.

DWMWA_CLOAK Use with DwmSetWindowAttribute. Cloaks the window such that it is not visible to the user. The window is still composed by DWM.

Using with DirectComposition: Use the DWMWA_CLOAK flag to cloak the layered child window when animating a representation of the window's content via a DirectComposition visual that has been associated with the layered child window. For more details on this usage case, see How to animate the bitmap of a layered child window.

Windows 7 and earlier: This value is not supported.

DWMWA_CLOAKED Use with DwmGetWindowAttribute. If the window is cloaked, provides one of the following values explaining why.
Name Value Meaning
DWM_CLOAKED_APP 0x0000001 The window was cloaked by its owner application.
DWM_CLOAKED_SHELL 0x0000002 The window was cloaked by the Shell.
DWM_CLOAKED_INHERITED 0x0000004 The cloak value was inherited from its owner window.
  Windows 7 and earlier: This value is not supported.
DWMWA_FREEZE_REPRESENTATION Use with DwmSetWindowAttribute. Freeze the window's thumbnail image with its current visuals. Do no further live updates on the thumbnail image to match the window's contents.

Windows 7 and earlier: This value is not supported.

DWMWA_LAST The maximum recognized DWMWINDOWATTRIBUTE value, used for validation purposes.

Requirements

   
Minimum supported client Windows Vista [desktop apps only]
Minimum supported server Windows Server 2008 [desktop apps only]
Header dwmapi.h

See Also