DOCUMENT:Q66246  04-DEC-1999  [win16sdk]
TITLE   :SAMPLE: Twins.exe Uses RegisterWindowMessage for Interapp Comm.
PRODUCT :Microsoft Windows Software Development Kit
PROD/VER:WINDOWS:3.0,3.1
OPER/SYS:
KEYWORDS:kbfile kbsample kb16bitonly kbGrpDSUser kbOSWin310 kbWndw kbWndwMsg

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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
=======

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().

MORE INFORMATION
================

The following file is available for download from the Microsoft Download
Center:

   Twins.exe
   (http://download.microsoft.com/download/platformsdk/sample79/3.1/W31/EN-US/Twins.exe)

For additional information about how to download Microsoft Support files, click
the article number below to view the article in the Microsoft Knowledge Base:

   Q119591 How to Obtain Microsoft Support Files from Online Services

Microsoft used the most current virus detection software available on the date of
posting to scan this file for viruses. Once posted, the file is housed on secure
servers that prevent any unauthorized changes to the file.

Additional query words:

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Keywords          : kbfile kbsample kb16bitonly kbGrpDSUser kbOSWin310 kbWndw kbWndwMsg 
Technology        : kbAudDeveloper kbWin3xSearch kbSDKSearch kbWinSDKSearch kbWinSDK300 kbWinSDK310
Version           : WINDOWS:3.0,3.1

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