BUG: Layered Windows Disappear During Calls to the LockWindowUpdate() Function (270624)


The information in this article applies to:

  • Microsoft Platform Software Development Kit (SDK) 1.0, when used with:
    • the operating system: Microsoft Windows 2000
This article was previously published under Q270624

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 that this is a bug in the Microsoft products that are 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.
Modification Type:MinorLast Reviewed:7/11/2005
Keywords:kbbug kbWndw KB270624
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