Function name: BroadcastSystemMessage

Defined in : User32

Requirements : Windows NT 4.0 or later; Windows 95 or later

Declaration:

Declare Function BroadcastSystemMessage Lib "user32" Alias "BroadcastSystemMessage" (ByVal dw As Long, pdw As Long, ByVal un As Long, ByVal wParam As Long, ByVal lParam As Long) As Long

Parameters:

* dwFlags Option flags. Can be a combination of the following values: BSF_FLUSHDISK Flush the disk after each recipient processes the message. BSF_FORCEIFHUNG Continue to broadcast the message, even if the time-out period elapses or one of the recipients is hung.. BSF_IGNORECURRENTTASK Do not send the message to windows that belong to the current task. This prevents an application from receiving its own message. BSF_NOHANG Force a hung application to time out. If one of the recipients times out, do not continue broadcasting the message. BSF_NOTIMEOUTIFNOTHUNG Wait for a response to the message, as long as the recipient is not hung. Do not time out. BSF_POSTMESSAGE Post the message. Do not use in combination with BSF_QUERY. BSF_QUERY Send the message to one recipient at a time, sending to a subsequent recipient only if the current recipient returns TRUE. * lpdwRecipients Pointer to a variable that contains and receives information about the recipients of the message. The variable can be a combination of the following values: BSM_ALLCOMPONENTS Broadcast to all system components. BSM_ALLDESKTOPS Windows NT only: Broadcast to all desktops. Requires the SE_TCB_NAME privilege. BSM_APPLICATIONS Broadcast to applications. BSM_INSTALLABLEDRIVERS Windows 95: Broadcast to installable drivers. Windows NT: This value is not meaningful. BSM_NETDRIVER Windows 95: Broadcast to Windows-based network drivers. Windows NT: This value is not meaningful. BSM_VXDS Windows 95: Broadcast to all system-level device drivers. Windows NT: This value is not meaningful. When the function returns, this variable receives a combination of these values identifying which recipients actually received the message. If this parameter is NULL, the function broadcasts to all components. * uiMessage Identifier of the system message. * wParam 32-bit message-specific value. * lParam 32-bit message-specific value.

Returns:

If the function succeeds, the return value is a positive value. If the function is unable to broadcast the message, the return value is -1. If the dwFlags parameter is BSF_QUERY and at least one recipient returned BROADCAST_QUERY_DENY to the corresponding message, the return value is zero.

Related functions:

Examples:

Broadcast System Message