SAMPLE: Using RegisterWindowMessage for Interapp Communication

 Last reviewed: February 15, 1996
Article ID: Q66246
The information in this article applies to:
  • Microsoft Windows Software Development Kit (SDK) for Windows versions 3.0 and 3.1

The RegisterWindowMessage() function associates a unique message number with a given message name. This message number is guaranteed to be unique throughout the system but may change between Windows sessions. The new message is typically used for communication between two cooperating applications.

Using RegisterWindowMessage() is an alternative to using DDE to communicate between two or more applications. This technique is most useful if the information to be passed between applications can be contained in the wParam and/or lParam parameter of the message.

A sample application is available that demonstrates how to implement communication between two cooperating applications, using RegisterWindowMessage().

Download TWINS.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 TWINS.EXE (size: 24241 bytes)
  • Internet (anonymous FTP) 

          ftp ftp.microsoft.com
      Change to the \SOFTLIB\MSLFILES directory
      Get TWINS.EXE (size: 24241 bytes)

Additional reference words: 3.00 3.10 softlib TWINS.EXE
KBCategory: kbprg kbfile
KBSubcategory: UsrMsg

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Last reviewed: February 15, 1996
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