Question

Using Delphi XE2 I wanted to make some buttons move in delphi application.

I wrote this code:

procedure TForm1.DoSomething;
var x : integer;
begin    
   for x := 200 downto 139 do begin
       // move two buttons
      Button1.Top := x;
      Button3.Top := x;
       // skip some repaints to reduce flickering
      if (x mod 7 = 1) then begin
          Form1.Repaint;
      Sleep(50);
   end;
end;

Unfortunately it still significantly flickers when running this procedure.

Here’s my question:
Is there any way, to make the animation smooth (without any flickering)?

Edit:
To make animation more smooth, change 50 to something smaller in sleep(50) and delete this line:

if(x mod 7 = 1) then begin

Answer 1

Set Form1.DoubleBuffered to True. You can do this in code, but I think the property is published in XE2, so you can set it in the Object Inspector as well.