GetQueueStatus function (winuser.h)

Retrieves the type of messages found in the calling thread's message queue.

Syntax

DWORD GetQueueStatus(
  [in] UINT flags
);

Parameters

[in] flags

Type: UINT

The types of messages for which to check. This parameter can be one or more of the following values.

Return value

Type: DWORD

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 GetMessage or PeekMessage 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.

The QS_ALLPOSTMESSAGE and QS_POSTMESSAGE flags differ in when they are cleared. QS_POSTMESSAGE is cleared when you call GetMessage or PeekMessage, whether or not you are filtering messages. QS_ALLPOSTMESSAGE is cleared when you call GetMessage or PeekMessage without filtering messages (wMsgFilterMin and wMsgFilterMax are 0). This can be useful when you call PeekMessage multiple times to get messages in different ranges.

Requirements

See also

Conceptual

GetInputState

GetMessage

Messages and Message Queues

PeekMessage

Reference