奢望回复 关于多媒体控件的使用

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

type
  TForm1 = class(TForm)
    Panel1: TPanel;
    MediaPlayer1: TMediaPlayer;
    OpenDialog1: TOpenDialog;
    Button1: TButton;
    TrackBar1: TTrackBar;
    Timer1: TTimer;
    procedure Button1Click(Sender: TObject);
    procedure Timer1Timer(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
var
  Form1: TForm1;
implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
   if OpenDialog1.Execute then
   with MediaPlayer1 do
   begin
     Close ;
     FileName :=OpenDialog1.FileName ;
     Open ;
     display:=panel1
     DisplayRect :=REct(0,0,Panel1.Width ,Panel1.Height );
     notify :=true;
     TrackBar1.Position :=length;
   end;
end;
为什么播放效果和人家的就不一样呢？？？

看看OpenDialog1中对文件格式过滤了没有，filter属性