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How to force window to repaint?

Sat, 08 Jan 2005 03:32:53 -0700

I thought UpdateWindow(hwnd) would do it, but it
doesn't. Do I need to actually create a separate
function to redraw the window and call this function
whenever I want to repaint the window?

Re: How to force window to repaint?

Sat, 08 Jan 2005 05:57:30 -0700

Maybe this works, but I didn't try:

HDC hdc = GetWindowDC(hWnd);
SendMessage(hWnd, WM_PAINT, (WPARAM)hdc, 0);
ReleaseDC(hdc);

Re: How to force window to repaint?

Sun, 09 Jan 2005 06:00:08 -0700

: Maybe this works, but I didn't try:
:
: HDC hdc = GetWindowDC(hWnd);
: SendMessage(hWnd, WM_PAINT, (WPARAM)hdc, 0);
: ReleaseDC(hdc);
:
The code above can cause trouble in some situations... This is how to force the redraw the right way:

InvalidateRect (hWnd, NULL, TRUE);
UpdateWindow (hWnd);

Also, this link:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/gdi/pantdraw_88ac.asp

mentions: "...The WM_PAINT message is generated by the system and should not be sent by an application..."

Re: How to force window to repaint?

Fri, 14 Jan 2005 08:34:07 -0700

: The code above can cause trouble in some situations... This is how to force the redraw the right way:
:

: InvalidateRect (hWnd, NULL, TRUE);
: UpdateWindow (hWnd);
:

: Also, this link:
:
: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/gdi/pantdraw_88ac.asp
:
: mentions: "...The WM_PAINT message is generated by the system and should not be sent by an application..."
:

I also read that, but there was no explanation other than "The WM_PAINT message is generated by the system" why it should not be used.
I'm curious. Why is it problematic? What do you mean with "in some situations"?

Re: How to force window to repaint?

Fri, 14 Jan 2005 15:38:55 -0700

: : The code above can cause trouble in some situations... This is how to force the redraw the right way:
: :

: : InvalidateRect (hWnd, NULL, TRUE);
: : UpdateWindow (hWnd);
: :

: : Also, this link:
: :
: : http://msdn.microsoft.com/library/default.asp?url=/library/en-us/gdi/pantdraw_88ac.asp
: :
: : mentions: "...The WM_PAINT message is generated by the system and should not be sent by an application..."
: :
:
: I also read that, but there was no explanation other than "The WM_PAINT message is generated by the system" why it should not be used.
: I'm curious. Why is it problematic? What do you mean with "in some situations"?
:
No idea why, but I trust Microsoft - if they say - it is no good, then it is no good.

Re: How to force window to repaint?

Sun, 16 Jan 2005 05:07:45 -0700

-- I trust Microsoft --

No comment.

Re: How to force window to repaint?

Sun, 16 Jan 2005 06:28:45 -0700

: -- I trust Microsoft --
:
: No comment.
:
<-Never heard of any programmer would send a WM_PAINT message.