BroadcastSystemMessage
[Now
Supported on Windows NT]
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.
long BroadcastSystemMessage(
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DWORD dwFlags, |
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LPDWORD lpdwRecipients, |
|
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UINT uiMessage, |
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WPARAM wParam,
|
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LPARAM lParam |
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); |
|
Parameters
dwFlags
Option flags.
Can be a combination of the following values:
|
Value |
Meaning |
|
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:
|
Value |
Meaning |
|
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.
Return Values
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.
Remarks
If BSF_QUERY
is not specified, the function sends the specified message to all requested
recipients, ignoring values returned by those recipients.