This program draw circles in random locations on screen. Form border style is set to NONE. At startup it automatically maximizes form size to fit screen size.

               Use system timer to draw circles randomly. Set timer event as follows

procedure TForm1.Timer1Timer(Sender: TObject);
Var
      X, Y : Integer;
begin
      { Change the color }
      DColor:=DColor+1;
      Form1.Canvas.Brush.Color:=DColor;
      { Create random coordinates for circles }
      Randomize;
      X:=Random(Form1.Width);
      Y:=Random(Form1.Height);
      Form1.Canvas.Ellipse(X-15,Y-15,X+15,Y+15);
end;

 

      Since in this program we set form style to NONE, as a result you want see any form control buttons on top right. In order to close your program use following FormClick event.

procedure TForm1.FormClick(Sender: TObject);
begin
      Close;
end;

 

      DColor variable hold the color value for circle. So at the beginning set this one to starting color. It's a Long Integer number.

procedure TForm1.FormCreate(Sender: TObject);
begin
      DColor:=10000000;
end;

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