GDI+ flickering problem

[dexto]

My application has a loop that refreshes every second.

while true
    _GDIPlus_GraphicsClear($GDI_Buffer)
    _GDIPlus_GraphicsDrawStringEx($GDI_Buffer, $time, $hFont, $tLayout, $hFormat, $hBrush)
    _GDIPlus_GraphicsDrawStringEx($GDI_Buffer, $weather, $dFont, $wLayout, $hFormat, $hBrush)
    _GDIPlus_GraphicsDrawImageRect($graphics, $bitmap, 0, 0, $width, $height)
sleep(1000)
wend

It seems from time to time whole window becomes black for a second and then comes back. What did I do wrong?

Thx guys, any suggestions are welcome.. I'm lost here.

[Andreik]

I think you should use double buffer.

http://www.autoitscript.com/forum/index.ph...mp;#entry617017

[dexto]

Thx Andreik,

It helps and I'm using it but its not entirely illuminating the flickering...

Turns out GDI+ has a flickering problem no way around it. I think is not designed for frame based applications may be nice GUI at most.

For some reason from time to time Windows clears GDI+ to black until redrawn..? :S

[monoceres]

Turns out GDI+ has a flickering problem no way around it. I think is not designed for frame based applications may be nice GUI at most.

For some reason from time to time Windows clears GDI+ to black until redrawn..? :S

There will be small flicker when redrawing the screen yes, it's because GDI+ is a slow sob when it comes to drawing images.

The window can also turn black when windows invalidates the window rect, this can happen if another windows covers your window. This happens mostly on systems <Vista.

[dexto]

more info:

There are methods that can be used to help with flickering (buffering is one of them).

Even if you might not use them at least this help explain and understand flickering in GDI.

http://stackoverflow.com/questions/197948/...-with-gdi-and-c

[dexto]

The window can also turn black when windows invalidates the window rect, this can happen if another windows covers your window. This happens mostly on systems <Vista.

I noticed that with the window!!!

For some apps even when you move you mouse fast over it it seem to work much faster!

I was always wondering why.

Edited July 2, 2009 by dexto

[Yashied]

Here's another way.

[dexto]

Its MUCH better now! Thx! The post above has some additional tricks that improve even farther.

Edited July 2, 2009 by dexto