SHSendMessageBroadcastA function (shlwapi.h)

Article
11/20/2024

[This function is available through Windows XP and Windows Server 2003. It might be altered or unavailable in subsequent versions of Windows.]

Sends a message to all top-level windows in the system.

Syntax

LRESULT SHSendMessageBroadcastA(
  [in] UINT   uMsg,
  [in] WPARAM wParam,
  [in] LPARAM lParam
);

Parameters

[in] uMsg

Type: UINT

The message to send.

[in] wParam

Type: WPARAM

Additional message-specific information.

[in] lParam

Type: LPARAM

Additional message-specific information.

Return value

Type: LRESULT

The return value is not meaningful.

Remarks

SHSendMessageBroadcast is equivalent to SendMessage with HWND_BROADCAST. To avoid causing the Shell to become unresponsive in the case where there could be a window in the system that is not responding to messages, use SHSendMessageBroadcast.

SHSendMessageBroadcast is not exported by name. SHSendMessageBroadcastA is exported from Shlwapi.dll as ordinal 432. SHSendMessageBroadcastW is exported from Shlwapi.dll as ordinal 433.

Note

The shlwapi.h header defines SHSendMessageBroadcast as an alias that automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that is not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.

Requirements

Requirement	Value
Minimum supported client	Windows XP [desktop apps only]
Minimum supported server	Windows Server 2003 [desktop apps only]
Target Platform	Windows
Header	shlwapi.h
DLL	Shlwapi.dll (version 5.0 or later)

Share via