获取新的动态创建的MediaPlayer实例的引用

调用方法后只需返回实例:

private System.Windows.Media.MediaPlayer playSound (string path)
{
    if (System.IO.File.Exists(path))
    {
       System.Windows.Media.MediaPlayer mp = new System.Windows.Media.MediaPlayer();
       mp.Open(new System.Uri(path));
       mp.Play();

       return mp;
    }
    return null;
}

在调用代码中,请在使用之前检查返回的对象是否不为null:

var mp = playSound(@"d:\music\file.mp3");
if(mp != null)
{
   //do something with mp
}

您还可以将此MediaPlayer对象保存在dictionary对象中,以便于操作。

Dictionary<string, System.Windows.Media.MediaPlayer> players = new Dictionary<string, System.Windows.Media.MediaPlayer>();
var mp = playSound(@"d:\music\file.mp3");
players.Add(btn.Text, mp); //Identifying media player by button text
// Later if a user press the button again and your default action is pause
if(players.ContainsKey(btn.Text))
   players[btn.Text].Pause();