unit1.pas

《Delphi百例》源码?禗elphi百例》源码

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs;

type
  TForm1 = class(TForm)
    procedure FormPaint(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.DFM}

procedure TForm1.FormPaint(Sender: TObject);
var i:Word;
    Dy,y:Real;
begin
  Dy:=ClientHeight/256;
  y:=0;
  for i:=255 Downto 0 do
    begin
    Canvas.brush.color:=$00000000+i*$10000;
    Canvas.fillrect(rect(0,round(y),clientwidth,round(y+Dy)));
    y:=y+Dy;
    end;
end;

end.