Am 08.02.2012 16:02, schrieb [email protected]:
I have played with Image.Update, .Invalidate and .Repaint, but none of
them seem to work for me. Only when I put Application.ProcessMessages
the painted images show on screen. See below for the testloop code. The
images are streamed from a file cache. For 24 frames this seems
overkill, but running at 24fps the memeory requirements quickly get very
large!
Image.Transparent is also set to false btw, which is default. Otherwise
the drawing on the canvas is even messed up.
Regards, Darius
procedure TForm1.Button1Click(Sender: TObject);
var
s: TDateTime;
i: Integer;
begin
s := now;
for i := 1 to 24 do
begin
if filecache_get_from_cache(i, png) then
begin
Image1.Picture.Bitmap.LoadFromRawImage(png.RawImage, False);
Application.ProcessMessages;
end;
end;
ShowMessage(FloatToStr(24 / ((now - s) * 24 * 3600)))
end;
Here it is clear that you need to use Application.ProcessMessages,
because "LoadFromRawImage" will only tell the control that it needs to
repaint itself, but does not execute this repainting (this is done in
Application.ProcessMessages). In the example you posted in the beginning
the call to Application.ProcessMessages is located inside the OnPaint
handler of the Image which is - in my opinion - not good. Maybe also the
loading of the image inside the OnPaint handler is not good...
Maybe you should try - like Felipe suggested - something else than
TImage. Try for example TPaintBox in combination with the
Application.OnIdle event:
procedure TForm1.ApplicationOnIdle(aSender: TObject; var aDone: Boolean);
begin
LoadNextImageFromCache; // this will load the next image into some
private variable of the form (let's call it fImage). [this is based on
your filecache_get_from_cache any you'll need to write it of course ;) ]
PaintBox1.Invalidate;
aDone := False; // important!
end;
procedure TForm1.PaintBox1Paint(aSender: TObject);
begin
PaintBox1.Canvas.Draw(fImage); // or however you'll get the content
of the fImage onto the canvas of the PaintBox
end;
Note: Don't forget to assign your ApplicationOnIdle to
Application.OnIdle or use the ApplicationProperties component located in
the Additional tab.
Regards,
Sven
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