SetMessageExtraInfo function (Windows)

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SetMessageExtraInfo function

Applies to: desktop apps only

Sets the extra message information for the current thread. Extra message information is an application- or driver-defined value associated with the current thread's message queue. An application can use the GetMessageExtraInfo function to retrieve a thread's extra message information.

Syntax

LPARAM WINAPI SetMessageExtraInfo(
  __in  LPARAM lParam
);

Parameters

lParam [in]

Type: LPARAM

The value to be associated with the current thread.

Return value

Type:

Type: LPARAM

The return value is the previous value associated with the current thread.

Requirements

Minimum supported client

Windows 2000 Professional

Minimum supported server

Windows 2000 Server

Header

Winuser.h (include Windows.h)

Library

User32.lib

DLL

User32.dll

See also

Reference
GetMessageExtraInfo
Conceptual
Messages and Message Queues

 

 

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Build date: 2/3/2012

Community Content

Thomas Lee
Questionable Minimum Supported Client/Server
Question: According to Raymond Chen [http://blogs.msdn.com/b/oldnewthing/archive/2010/11/29/10097548.aspx] the function was added in 1990. So either it took 10 years for that source file to become a part of a release build, or the Minimum Supported Client/Server values stated here are incorrect (W2k is listed).

Added: Looking at Winuser.h it is defined for WINVER >= 0x0400, so that means it's NT/98

Answer: Microsoft are now deliberately lying about the "Minimum Supported Client/Server" on every single page of the MSDN documentation! Even functions introduced in 1983 that go all the way back to Windows 1.0 will still say "Windows 2000 Professional" as the minimum requirement. So "Windows 2000 Professional" actually means "Introduced in Windows 2000 or earlier". Lying so openly is just one of the many good reasons people dislike Microsoft.

Medinoc
Return value documentation is missing (corrected)
The Return Value section of this documentation page is empty.