GetQueueStatus
The GetQueueStatus
function returns flags that indicate the type of messages found in the calling
thread s message queue.
DWORD GetQueueStatus(
|
UINT flags |
// queue-status
flags |
|
); |
|
Parameters
flags
Specifies
queue-status flags giving the types of messages to check for. This parameter
can be a combination of the following values:
|
Value |
Meaning |
|
QS_ALLEVENTS |
An input,
WM_TIMER, WM_PAINT, WM_HOTKEY, or posted message is in the queue. |
|
QS_ALLINPUT |
Any message
is in the queue. |
|
QS_HOTKEY |
A WM_HOTKEY
message is in the queue. |
|
QS_INPUT |
An input
message is in the queue. |
|
QS_KEY |
A WM_KEYUP,
WM_KEYDOWN, WM_SYSKEYUP, or WM_SYSKEYDOWN message is in the queue. |
|
QS_MOUSE |
A
WM_MOUSEMOVE message or mouse-button message (WM_LBUTTONUP, WM_RBUTTONDOWN,
and so on). |
|
QS_MOUSEBUTTON |
A
mouse-button message (WM_LBUTTONUP, WM_RBUTTONDOWN, and so on). |
|
QS_MOUSEMOVE |
A
WM_MOUSEMOVE message is in the queue. |
|
QS_PAINT |
A WM_PAINT
message is in the queue. |
|
QS_POSTMESSAGE |
A posted
message (other than those just listed) is in the queue. |
|
QS_SENDMESSAGE |
A message
sent by another thread or application is in the queue. |
|
QS_TIMER |
A WM_TIMER
message is in the queue. |
Return Values
The
high-order word of the return value indicates the types of messages currently
in the queue. The low-order word indicates the types of messages that have been
added to the queue and that are still in the queue since the last call to the GetQueueStatus,
GetMessage,
or PeekMessage
function.
Remarks
The presence
of a QS_ flag in the return value does not guarantee that a subsequent call to
the PeekMessage or GetMessage function will return a message. GetMessage
and PeekMessage perform some internal filtering that may cause the
message to be processed internally. For this reason, the return value from GetQueueStatus
should be considered only a hint as to whether GetMessage or PeekMessage
should be called.
See Also