Q50741: Failure to Load Resources When All File Handles Are Used

Article: Q50741
Product(s): Microsoft Windows Software Development Kit
Version(s): WINDOWS:3.0,3.1
Operating System(s): 
Keyword(s): kb16bitonly
Last Modified: 06-NOV-1999

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The information in this article applies to:

- Microsoft Windows Software Development Kit (SDK) versions 3.0, 3.1 
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SUMMARY
=======

A Windows-based application should not use all available file handles. Doing so
may prevent Windows from being able to load the application's resources.

When Windows has to open the application's .EXE file to retrieve a resource (such
as the icon's bitmap), it uses one of the application's file handles. If the
application has used all available file handles, Windows cannot load the
resource.

For example, suppose LoadIcon() was called previously to obtain an icon handle
successfully, and the icon is being used as a window's icon. The rendering of
the icon will fail if the application is using all the file handles. For
example, if the window is to be minimized, the icon will be displayed as a black
block on the screen.

NOTE: LoadIcon() loads in the logical information of the icon; the bitmap of the
icon is not loaded until it is going to be used.

Under MS-DOS, an application has 20 file handles when it begins executing. Five
of these handles (that is, STDIN, STDOUT, STDPRN, STDERR, and STDAUX) are
automatically opened for use by the operating system. This leaves a total of 15
file handles available for an application. If a Windows-based application needs
more file handles open at any given time, it can use the SetHandleCount() API.

Additional query words: 3.00 3.10 no32bit

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Keywords          : kb16bitonly 
Technology        : kbAudDeveloper kbWin3xSearch kbSDKSearch kbWinSDKSearch kbWinSDK300 kbWinSDK310
Version           : WINDOWS:3.0,3.1

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