Microsoft KB Archive/270624

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BUG: Layered Windows Disappear During Calls to the LockWindowUpdate Function

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Q270624

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The information in this article applies to:


 * Microsoft Win32 Software Development Kit (SDK), on platform(s):
 * the operating system: Microsoft Windows 2000

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SYMPTOMS
Windows that have the WS_EX_LAYERED extended style disappear when the LockWindowUpdate function is called.

RESOLUTION
To prevent this behavior, the WS_EX_LAYERED style must be removed before calling LockWindowUpdate, then reapplied after window updating has been restored.

STATUS
Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article.

MORE INFORMATION
The WS_EX_LAYERED extended style is used to create a layered or transparent window. Layered windows can make use of alpha blending effects and do not need to be rectangular.

Additional query words:

Keywords : kbOSWin2000 kbGrpDSUser kbWndw kbDSupport

Issue type : kbbug

Technology : kbWin32SDKSearch kbAudDeveloper kbSDKSearch kbWin32sSearch