android 播放器遇到prepareAsync called in state 8

package com.example.mediaplayer_1219;

import java.io.IOException;

import android.media.MediaPlayer;

import android.os.Bundle;

import android.app.Activity;

import android.view.Menu;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

public class MainActivity extends Activity {

private Button start = null;

private Button stop = null;

private Button reset = null;

private MediaPlayer player = null;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

start = (Button) super.findViewById(R.id.start);

stop = (Button) super.findViewById(R.id.stop);

reset = (Button) super.findViewById(R.id.reset);

start.setOnClickListener(new OnClickListener() {



@Override

public void onClick(View arg0) {

// TODO Auto-generated method stub

player = MediaPlayer.create(MainActivity.this, R.raw.xi);

if(player!=null){ //判断播放器有没有被占用，如果被占用就关掉

player.stop();

}

try {

player.prepare();

player.start();

} catch (IllegalStateException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}



}

});

stop.setOnClickListener(new OnClickListener() {



@Override

public void onClick(View arg0) {

// TODO Auto-generated method stub

player.stop();



}

});

reset.setOnClickListener(new OnClickListener() {



@Override

public void onClick(View arg0) {

// TODO Auto-generated method stub

player.reset();

}

});

}



}