音乐播放器

public class MainActivity extends Activity {
	private static final String TAG = "MainActivity";
	private EditText filenameText;
	private MediaPlayer mediaPlayer;
	private String filename;
	private int position;
	@Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        filenameText = (EditText) findViewById(R.id.filename);
        
        mediaPlayer = new MediaPlayer();
        ButtonClickListener listener = new ButtonClickListener();
        Button playButton = (Button) findViewById(R.id.play);
        Button pauseButton = (Button) findViewById(R.id.pause);
        Button resetButton = (Button) findViewById(R.id.reset);
        Button stopButton = (Button) findViewById(R.id.stop);
 
        playButton.setOnClickListener(listener);
        pauseButton.setOnClickListener(listener);
        resetButton.setOnClickListener(listener);
        stopButton.setOnClickListener(listener);
        
        }
	
	
    
    @Override
	protected void onRestoreInstanceState(Bundle savedInstanceState) {
    	this.filename = savedInstanceState.getString("filename");
    	this.position = savedInstanceState.getInt("position");
    	super.onRestoreInstanceState(savedInstanceState);
	}



	@Override
	protected void onSaveInstanceState(Bundle outState) {
		outState.putString("filename", filename);
		outState.putInt("position", position);
		super.onSaveInstanceState(outState);
	}



	@Override
	protected void onPause() {//如果突然电话到来，停止播放音乐
    	if(mediaPlayer.isLooping()){
    		position = mediaPlayer.getCurrentPosition();//保存当前播放点
    		mediaPlayer.stop();
    	}
    	super.onPause();
	}



	@Override
	protected void onResume() {//如果电话结束，继续播放音乐
		if(position>0 && filename != null){
			try {
				play();
				mediaPlayer.seekTo(position);
				position = 0;
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			
		}
		super.onResume();
	}



	@Override
	protected void onDestroy() {
    	mediaPlayer.release();
		super.onDestroy();
	}



	private final class ButtonClickListener implements View.OnClickListener{

		@Override
		public void onClick(View v) {
			filename = filenameText.getText().toString();
			Button button = (Button) v;
			try {
				switch (v.getId()) {
				case R.id.play:
					
					play();
					break;

				case R.id.pause:
					if(mediaPlayer.isPlaying()){
						mediaPlayer.pause();
						button.setText(R.string.continue1);
					}else{
						mediaPlayer.start();//继续播放
						button.setText(R.string.pause);
					}
					
					break;
					
				case R.id.reset:
					if(mediaPlayer.isPlaying()){
						mediaPlayer.seekTo(0);
					}else{
						play();
					}
					break;
					
				case R.id.stop:
					if(mediaPlayer.isPlaying()){
						mediaPlayer.stop();
					}
					break;
				}
			} catch (Exception e) {
				Log.e(TAG, e.toString());
			}
		}


    	
    }
	private void play() throws IOException {
		File audioFile = new File(Environment.getExternalStorageDirectory(),filename);
		mediaPlayer.reset();
		mediaPlayer.setDataSource(audioFile.getAbsolutePath());
		mediaPlayer.prepare();
		mediaPlayer.start();//播放
	}
}