track_unit.pas

一系列DELPHI的控件如何使用的例子,例子有的比较简单,但是能详细的说明了控件的使用,对许多刚涉足DELPHI的朋友会很有帮助的

unit track_Unit;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, ExtCtrls, ComCtrls;

type
  TForm1 = class(TForm)
    HeaderControl1: THeaderControl;
    StatusBar1: TStatusBar;
    Timer1: TTimer;
    Image1: TImage;
    TrackBar1: TTrackBar;
    ProgressBar1: TProgressBar;
    Timer2: TTimer;
    procedure Timer1Timer(Sender: TObject);
    procedure Timer2Timer(Sender: TObject);
    procedure TrackBar1Change(Sender: TObject);
  private
    r:integer;
    procedure drawimage(radius:integer);
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}
procedure tform1.drawimage(radius:integer);
var x1,x2,y1,y2:integer;
begin
  x1:=90-radius;             //设置椭圆的左上角坐标
  y1:=x1;
  x2:=90+radius;             //设置椭圆的右上角坐标
  y2:=x2;
  with Image1.canvas do
    begin
    brush.Style:=bssolid;     //设置格式刷
    brush.Color:=clwindow;   //设置填充色
    fillrect(image1.ClientRect); //调用image的填充方法
    brush.Color:=clred;          //重新设置填充色
    ellipse(x1,y1,x2,y2);        //调用画椭圆方法
    end;
    TrackBar1.Position:=radius;  //设置滚动条位置
    ProgressBar1.Position:=radius;
end;

procedure TForm1.Timer1Timer(Sender: TObject);
begin
   HeaderControl1.Sections[0].Text:='今天日期：  '+datetostr(date);
   HeaderControl1.Sections[1].Text:='现在时间：  '+timetostr(time);
   StatusBar1.Panels[0].Text:='今天日期：  '+datetostr(date);
   StatusBar1.Panels[1].Text:='现在时间：  '+timetostr(time);
end;

procedure TForm1.Timer2Timer(Sender: TObject);
begin
    drawimage(r);    //调用画椭圆过程
    r:=r+2;
    if r>90 then
       Timer2.Enabled:=false;
end;

procedure TForm1.TrackBar1Change(Sender: TObject);
begin
    drawimage(TrackBar1.Position);     //根据滚动条位置画椭圆
end;

end.