Q35767: HOWTO: Obtain an Application’s Instance Handle

Article: Q35767
Product(s): Microsoft Windows Software Development Kit
Version(s): WINDOWS:3.0,3.1
Operating System(s): 
Keyword(s): kb16bitonly kbSDKPlatform kbGrpDSUser kbWndw
Last Modified: 06-NOV-1999

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The information in this article applies to:

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

Many Windows API functions require an application's instance handle as a
parameter. This article describes three methods that an application can use to
obtain its instance handle.

MORE INFORMATION
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Depending on the situation, an application might use any of the following three
methods to obtain its instance handle:

1. The hInstance parameter to the WinMain procedure is the application's
  instance handle. The application can save this value in a global variable,
  making it available throughout the application.

2. The lParam parameter of the WM_CREATE message points to a CREATESTRUCT data
  structure, and the hInstance field of this structure is the application's
  instance handle. During the processing of the WM_CREATE message a window
  procedure can save this value in a static variable, as follows:

     hInst = ((LPCREATESTRUCT)lParam)->hInstance;

  This variable would then be available during all subsequent calls to the
  window procedure.

3. Given a window handle for one of its windows, an application can obtain its
  instance handle by calling the GetWindowWord function:

     GetWindowWord(hWnd, GWW_HINSTANCE)

Additional query words:

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

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