CMsgThread.ThreadMessageProc method
[The feature associated with this page, DirectShow, is a legacy feature. It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation. Those features have been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use MediaPlayer, IMFMediaEngine and Audio/Video Capture in Media Foundation instead of DirectShow, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]
Processes requests. This is a pure virtual member function.
Syntax
virtual LRESULT ThreadMessageProc(
UINT uMsg,
DWORD dwFlags,
LPVOID lpParam,
CAMEvent *pEvent
);
Parameters
-
uMsg
-
Request code.
-
dwFlags
-
Optional flag parameter to request.
-
lpParam
-
Optional pointer to extra data or a return data block.
-
pEvent
-
Optional pointer to an event object.
Return value
Any nonzero return causes the thread to exit. Returns zero unless an exit request has been processed recently.
Remarks
This pure virtual function must be overridden in your derived class. It will be called once for each request queued by a call to the CMsgThread::PutThreadMsg member function.
The member function defines the four parameters. Typically, use the uMsg parameter to indicate the request, and the other three parameters will be optional additional parameters. The calling application can supply a pointer to a CAMEvent object in the pEvent parameter if your application requires it. You must set this event after processing the event by using an expression such as:
pEvent->SetEvent
One request code must be set aside to tell the worker thread to exit. Upon receiving this request, return 1 from this member function. Return 0 if you do not want the worker thread to exit.
Requirements
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| Library |
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