Subclassing and Hooking with Visual Basic

Name

PeekMessage

Synopsis

PeekMessage is similar to GetMessage in that it gets a message from the message queue of the thread that calls this. The main difference is that PeekMessage does not automatically remove the message from the message queue, and GetMessage does.

Public Declare Function PeekMessage Lib "user32" Alias "PeekMessageA" _
		(lpMsg As MSG, ByVal hwnd As Long, ByVal wMsgFilterMin As Long, _
		ByVal wMsgFilterMax As Long, ByVal wRemoveMsg As Long) As Long

Parameters

lpMsg

A Long pointer to an MSG structure.

hwnd

The handle of the window whose messages are to be read from the queue. If this is zero, all messages will be read.

wMsgFilterMin

The minimum message value that is read from the message queue.

wMsgFilterMax

The maximum message value that is retrieved from the message queue. If this value is zero, all messages starting with the wMsgFilterMin value are read from the message queue.

wRemoveMsg

If this is set to 1, the message is read and then removed from the queue. If this is set to 0, the message is read but left on the queue.

Return Value

If there are no messages on the queue, the return value for this function is zero. A nonzero return value means that a message has been read from the queue.