unit1.pas

Delphi7应用编程150例 附书源码

unit Unit1;

interface

uses
  SysUtils, WinTypes, WinProcs, Messages, Classes, Graphics, Controls,
  Forms, Dialogs, ExtCtrls;

type
  TForm1 = class(TForm)
    Timer1: TTimer;
    Image1: TImage;
    procedure FormCreate(Sender: TObject);
    procedure Timer1Timer(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.DFM}

procedure TForm1.FormCreate(Sender: TObject);
begin
    BeginPath(Canvas.Handle);
    SetBkMode(Canvas.Handle, TRANSPARENT );
    Canvas.Ellipse(0,0,Width,Height);
    EndPath(Canvas.Handle);
    SetWindowRgn( Handle, PathToRegion(Canvas.Handle), True );
end;

procedure TForm1.Timer1Timer(Sender: TObject);
var
  MyNow      : TDateTime;
  Hour, Min, Sec, mSec  : Word;
  vh, vm, vs : Real;
begin
  Self.Refresh;
  MyNow := Now;
  DecodeTime(MyNow,Hour,Min,Sec,mSec);

  vh := Hour/12.0*2*Pi;
  vm := Min/60.0*2*Pi;
  vs := Sec/60.0*2*Pi;

  with Canvas do
  begin
    Pen.Width:=4;
    Pen.Color := clBlack;
    MoveTo(60,60);
    LineTo(60+Round(25*Sin(vh)),60-Round(25*Cos(vh)));
    Pen.Width:=2;
    Pen.Color := clBlack;
    MoveTo(60,60);
    LineTo(60+Round(45*Sin(vm)),60-Round(45*Cos(vm)));
    Pen.Width:=1;
    Pen.Color := clRed;
    MoveTo(60,60);
    LineTo(60+Round(55*Sin(vs)),60-Round(55*Cos(vs)));
  end;
end;

end.