WH_CALLWNDPROC, WH_GETMESSAGE Hooks Sample Code

 Last reviewed: February 15, 1996
Article ID: Q81332
The information in this article applies to:
  • Microsoft Windows Software Development Kit (SDK) for Windows version 3.1

HOOKALL2 is a file in the Microsoft Software Library that demonstrates using the WH_GETMESSAGE and WH_CALLWNDPROC hooks in Windows 3.1. HOOKALL2 contains the code for a dynamic-link library (DLL) with functions that set and remove the hooks, as well as the hook filter functions. The DLL uses the new hook functions provided by Windows 3.1: SetWindowsHookEx, UnhookWindowsHookEx, and CallNextHookEx. HOOKALL2 also contains code for a TESTHOOK application that tests the DLL.

HOOKALL2 updates the HOOKALL sample to use the features provided by Windows 3.1. For more information about HOOKALL, query on the following words in the Microsoft Knowledge Base: 

   hookall
Download HOOKALL2.EXE, a self-extracting file, from the Microsoft Software Library (MSL) on the following services:
  • Microsoft Download Service (MSDL) 

          Dial (206) 936-6735 to connect to MSDL
      Download HOOKALL2.EXE (size: 26821 bytes)
  • Internet (anonymous FTP) 

          ftp ftp.microsoft.com
      Change to the \SOFTLIB\MSLFILES directory
      Get HOOKALL2.EXE (size: 26821 bytes)

With the exception of WM_LBUTTONDOWN messages, the hook filter functions pass all messages directly to the next hook function in the hook chain. When they receive a WM_LBUTTONDOWN message, the filter functions draw a rectangle of random size and color in the TESTHOOK application's client area. One corner of the rectangle is at the point where the user pressed the mouse button.

Additional reference words: 3.10 softlib HOOKALL2.EXE
KBCategory: kbprg kbfile
KBSubcategory: UsrHks

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Last reviewed: February 15, 1996
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