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BroadcastSystemMessage The BroadcastSystemMessage function sends a message to the specified recipients. The recipients can be applications, installable drivers, Windows-based network drivers, system-level device drivers, or any combination of these system components.
VB4-32,5,6
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 |
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Operating Systems Supported |
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Requires Windows NT 4.0 or later; Requires Windows 95 or later |
- 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. |
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. |
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