Rectangle (Delphi)

Description

This example draws many rectangles of various sizes and colors on a form maximized to fill the entire screen. To run the code, drop a TTimer component on the form and use the object inspector to create the OnTimer and OnActivate event handlers.

Code

var
  X, Y: Integer;
procedure TForm1.FormActivate(Sender: TObject);
begin
  WindowState := wsMaximized;
  Timer1.Interval := 50;
  Randomize;
end;
 
procedure TForm1.Timer1Timer(Sender: TObject);
begin
  X := Random(Screen.Width - 10);
  Y := Random(Screen.Height - 10);
  Canvas.Pen.Color := Random(65535);
  case Random(5) of
    0: Canvas.Pen.Style := psSolid;
    1: Canvas.Pen.Style := psDash;
    2: Canvas.Pen.Style := psDot;
    3: Canvas.Pen.Style := psDashDot;
    4: Canvas.Pen.Style := psDashDotDot;
  end;
  Canvas.Rectangle(X, Y, X + Random(400), Y + Random(400));
end;

Uses

• Vcl.Graphics.TCanvas.Rectangle ( fr | de | ja )
• Vcl.Graphics.TPen.Style ( fr | de | ja )
• Vcl.Graphics.TPen.Color ( fr | de | ja )
• System.Random ( fr | de | ja )
• System.Randomize ( fr | de | ja )