How can I get Form1 redraw?
lazarus / 8-Other

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dek · 2008-06-06 22:23

Hi, I am very new in Lazarus programing on Windows platform.
I have Pascal programing experience on Turbo Pascal on DOS
and Virtual Pascal on OS/2.

But, today I have started to try Lazarus and got a problem
on the code below.

Form1 has Button1 and ProgressBar1. Clicking Button1,
it starts the following procedure and a message
box appears. After I click Ok on the massage box, it is still
on screen and starts ProgressBar1 moving. I think that form1
does not have refresh at the moment. When this procedure
(for loop) finishs, it has refresh.

I have tried to erase the message box after clicking OK button
using "form1.update" and/or "form1.refresh" as shown in the code
below. But it did not work.

Could you tell me what is wrong my code? Haw I can get Form1
redraw?


procedure TForm1.Button1Click(Sender: TObject);
var
  i  : integer;
begin
  ShowMessage('Hello World!');
  form1.Update;
  For i:=1 to 10 do
  begin
    ProgressBar1.Position:=i*10;
    delay(100);
  end;
  Button2.Enabled:=true;
  Button2.SetFocus;
end;

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theo · 2008-06-07 10:24

Try Application.Processmessages instead of form1.update.

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dek · 2008-06-07 12:27

Hi theo,

Yeah, it works. Thanks.

Where or How can I get this kind of information?

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theo · 2008-06-07 12:57

Hmm, difficult if you don't know what to look for ;-)
I'd recommend a good delphi book or the forum.

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dek · 2008-06-07 13:43

Ok.

I will have a Delphi book.
Thanks.