SetMessageExtraInfo function (winuser.h)

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 SetMessageExtraInfo(
  [in] LPARAM lParam
);

Parameters

[in] lParam

Type: LPARAM

The value to be associated with the current thread.

Return value

Type: LPARAM

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

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Target Platform	Windows
Header	winuser.h (include Windows.h)
Library	User32.lib
DLL	User32.dll
API set	ext-ms-win-ntuser-message-l1-1-0 (introduced in Windows 8)

See also

Conceptual

GetMessageExtraInfo

Messages and Message Queues

Reference