给 "blog V5" 的关于 TrackBar 控件的简单例子

问题来源: http://www.cnblogs.com/del/archive/2008/06/14/1220638.html#1225896

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例一效果图:

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例一代码:

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unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    TrackBar1: TTrackBar;
    procedure TrackBar1Change(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.TrackBar1Change(Sender: TObject);
begin
  Self.Text := IntToStr(TrackBar1.Position);
end;

end.

例二效果图:

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例二代码:

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unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    TrackBar1: TTrackBar;
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    procedure FormCreate(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
begin
  Button1.Caption := '变';
  Button2.Caption := '再变';
  Button3.Caption := '还原';
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  TrackBar1.ShowSelRange := False;  
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  TrackBar1.Orientation := trVertical;
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
  TrackBar1.ShowSelRange := True;
  TrackBar1.Orientation := trHorizontal;
end;

end.

例三效果图:

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例三代码:

---

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    TrackBar1: TTrackBar;
    Panel1: TPanel;
    procedure FormCreate(Sender: TObject);
    procedure TrackBar1Change(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
begin
  TrackBar1.ShowSelRange := False;
  TrackBar1.Min := 1;
  TrackBar1.Max := ClientWidth;
  TrackBar1.Position := ClientWidth div 2;
  TrackBar1.Height := 23;
  Panel1.Left := 0;
end;

procedure TForm1.TrackBar1Change(Sender: TObject);
begin
  Panel1.Width := TrackBar1.Position;
end;

end.