怎样用关联打开文件(25分)

就像Media Player 那样。。
在程序里怎样做 才能做到一执行该媒体文件。。。
直接调用关联的程序。。。并打开。。
怎样才能打开该媒体文件？？？

ShellExecute

这个问题应该还是操作注册表的一个问题，可以看看注册表中HKEY_CLASSES_ROOT的
项，应该在这里把你的文件和要用哪个程序打开相关联起来应该就可以了。

在详细一些。。。
在哪用shellexecute???

unit Unit1;

interface

uses
Windows, Messages,Registry, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
StdCtrls,shellapi, ExtCtrls, MPlayer;

type
TForm1 = class(TForm)
Panel1: TPanel;
OpenDialog1: TOpenDialog;
MediaPlayer1: TMediaPlayer;
procedure FormCreate(Sender: TObject);
procedure MediaPlayer1Click(Sender: TObject; Button: TMPBtnType;
var DoDefault: Boolean);
procedure MediaPlay(PlayFile:string);
procedure FormShow(Sender: TObject);
procedure Panel1DblClick(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;
const
cMyExe = '.mp3'; //文件扩展名

implementation

{$R *.DFM}

procedure TForm1.FormCreate(Sender: TObject);

var
Reg: TRegistry;
begin
Reg := TRegistry.Create;
try
Reg.RootKey :=HKEY_CLASSES_ROOT;
// Reg.OpenKey(cMyExe+'/DefaultIcon', True);
// Reg.WriteString('', Application.ExeName + ',0');
reg.OpenKey(cMyExe,true);
reg.WriteString('','myfile');
Reg.CloseKey;
Reg.OpenKey('myfile/shell/open/command', True);
Reg.WriteString('',Application.ExeName + ' %1');
Reg.CloseKey;
finally
Reg.Free;
end;
end;


procedure TForm1.MediaPlayer1Click(Sender: TObject; Button: TMPBtnType;
var DoDefault: Boolean);
begin
try
if Button=btPlay then
begin
MediaPlay(mediaplayer1.FileName);
end;
except
showmessage('error');
end;

end;

procedure TForm1.MediaPlay(PlayFile: string);
begin
with mediaplayer1 do begin
FileName:=PlayFile;
AutoEnable:=true;
AutoRewind:=true;
Open;
Play;
end;
end;

procedure TForm1.FormShow(Sender: TObject);
begin

if paramstr(1)<>'' then begin
MediaPlay(paramstr(1));

end;
end;

procedure TForm1.Panel1DblClick(Sender: TObject);
begin
try
if OpenDialog1.Execute then
MediaPlay(OpenDialog1.FileName);
except
showmessage('error');
end;
end;

end.

uses shellapi;

ShellExecute(0,nil,'文件名',nil,nil,SW_NORMAL);

接受答案了.