小的音乐播放器，为什么到结束了报异常

u010016914 2014-04-23 09:24:16

异常信息



04-23 13:17:04.766: W/dalvikvm(2271): threadid=11: thread exiting with uncaught exception (group=0x409961f8)

04-23 13:17:04.766: E/AndroidRuntime(2271): FATAL EXCEPTION: Thread-72

04-23 13:17:04.766: E/AndroidRuntime(2271): java.lang.IllegalStateException

04-23 13:17:04.766: E/AndroidRuntime(2271): 	at android.media.MediaPlayer.isPlaying(Native Method)

04-23 13:17:04.766: E/AndroidRuntime(2271): 	at com.example.audioplayer.MainActivity$1.run(MainActivity.java:53)

异常在53行，已经标出

package com.example.audioplayer;



import android.app.Activity;

import android.media.AudioManager;

import android.media.MediaPlayer;

import android.media.MediaPlayer.OnCompletionListener;

import android.os.Bundle;

import android.view.View;

import android.widget.ImageButton;

import android.widget.SeekBar;

import android.widget.SeekBar.OnSeekBarChangeListener;



public class MainActivity extends Activity {



	private ImageButton playIB;

	private SeekBar playSK;

	private MediaPlayer mediaPlayer;



	@Override

	protected void onCreate(Bundle savedInstanceState) {

		super.onCreate(savedInstanceState);

		setContentView(R.layout.activity_main);

		playIB = (ImageButton) findViewById(R.id.playIB);

		playSK = (SeekBar) findViewById(R.id.playSK);

	}



	public void play(View v) throws Exception {

		if (mediaPlayer == null) {

			mediaPlayer = new MediaPlayer();

			mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);

			mediaPlayer.setDataSource("/mnt/sdcard/a.mp3");

			mediaPlayer.prepare();

			mediaPlayer.start();

			mediaPlayer.setOnCompletionListener(new MyCompletionListener());

			handleSeek();

		} else if (mediaPlayer.isPlaying()) {

			mediaPlayer.pause();



		} else {

			mediaPlayer.start();

		}

		playIB.setImageResource(mediaPlayer.isPlaying() ? android.R.drawable.ic_media_pause

				: android.R.drawable.ic_media_play);



	}



	private void handleSeek() {

		playSK.setOnSeekBarChangeListener(new MyOnSeekBarChangeListener());

		playSK.setMax(mediaPlayer.getDuration());

		new Thread() {

			public void run() {

				while (mediaPlayer != null) {

			        	if (mediaPlayer.isPlaying() && !playSK.isPressed()) {[/color]

//这行有异常

						playSK.setProgress(mediaPlayer.getCurrentPosition());

						try {

							Thread.sleep(100);

						} catch (InterruptedException e) {

							e.printStackTrace();

						}

					}

				}

			};

		}.start();

	}



	private class MyOnSeekBarChangeListener implements OnSeekBarChangeListener {



		@Override

		public void onProgressChanged(SeekBar seekBar, int arg1, boolean arg2) {



		}



		@Override

		public void onStartTrackingTouch(SeekBar seekBar) {



		}



		@Override

		public void onStopTrackingTouch(SeekBar seekBar) {

			mediaPlayer.seekTo(playSK.getProgress());

		}



	}



	private class MyCompletionListener implements OnCompletionListener {



		public void onCompletion(MediaPlayer mediaPlayer) {

			mediaPlayer.stop();

			mediaPlayer.release();

			mediaPlayer = null;

			playIB.setImageResource(android.R.drawable.ic_media_play);

			playSK.setProgress(0);

		}



	}



	@Override

	protected void onDestroy() {

		mediaPlayer.stop();

		mediaPlayer.release();

		mediaPlayer = null;

		super.onDestroy();

	}



}