RE: OnIdle called only while mouse's moving

From:
=?Utf-8?B?RmVpIFh1?= <FeiXu@discussions.microsoft.com>
Newsgroups:
microsoft.public.vc.mfc
Date:
Sat, 8 Jul 2006 11:03:01 -0700
Message-ID:
<C81328DC-B792-4E5B-A9FD-F0D201E60519@microsoft.com>
"Peppe" wrote:

Hi
I need to update one class data and the view during the idle, I used this
method in the Cdoc:
void CMyAppDoc::OnIdle(){

    theClass->Update();
    POSITION pos = GetFirstViewPosition();
    CView* pView = GetNextView(pos);
    pView->Invalidate(true);
    pView->UpdateWindow();
}

It works only when I move the mouse, what's wrong? Z_Z

thanks


Nothing is wrong, I can explain it is by design.
Please take a look at the source code of int CWinThread::Run(), in that
function, IsIdleMessage() is called, and in IsIdleMessage() WM_PAINT is
ignored, which means WM_PAINT will not cause OnIdle to be called, for windows
think it's just a WM_PAINT message and will not change the UI.
Your UpdateWindow() only post a WM_PAINT message, the message queue is not
empty but it's ignored by IsIdleMessage(), that's why.
But when you move your mouse, the message queue is filled with some
WM_MOUSEMOVE and it's not ignored for the position changes. So your OnIdle()
is called again.

My suggestion is to move your Invalidate & UpdateWindow code to somewhere
else.

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