Using UnregisterClass When Removing Custom Control Class

Last reviewed: November 2, 1995
Article ID: Q67248

The information in this article applies to:

Microsoft Windows Software Development Kit (SDK) versions 3.0 and 3.1

Microsoft Win32 Application Programming Interface (API) included with:

    - Microsoft Windows NT versions 3.5 and 3.51
    - Microsoft Windows 95 version 4.0

In the Microsoft Windows environment, when no running application requires a custom control class, the class should be removed from memory to free the system resources it uses.

If an application registers a control class for temporary use, the application should use the UnregisterClass function when the control is no longer needed. If the application is terminated, Windows automatically removes any classes that the application registered; therefore, explicit use of UnregisterClass is not required. However, pairing calls to the RegisterClass and UnregisterClass functions is a good programming practice.

Additional reference words: 3.00 3.10 3.50 3.51 4.00 95
KBCategory: kbui
KBSubcategory: UsrCtl

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Last reviewed: November 2, 1995
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