Mediaplayer与SurfaceView 在程序切换到后台再恢复播放，有声音没图像！

[dong_seraph]

最近做一个项目，要求播放一个特定的网络视频，我用Android自带的MediaPlayer 与SurfaceView实现！其中有项要求，在播放的Activity切换到后台后，要求暂停播放，在切会前台后。恢复播放！我是在onStop() 中调用MediaPlayer.pause();在onStart()中根据记录的状态调用MediaPlayer.start();现在的问题是，在我恢复播放的时候，声音出来了，但是屏幕一直是黑屏！找了两天一直没有原因，那位大侠能给点提示！

[dong_seraph]

木有人？？？

[b87936260]

重新起来会走surfaceCreate，在这里面重绘

[花谢尊前不敢香]

你没有监听callback。
import android.app.Activity;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnPreparedListener;
import android.os.Bundle;
import android.os.Environment;
import android.view.SurfaceHolder;
import android.view.SurfaceHolder.Callback;
import android.view.SurfaceView;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends Activity {
    private EditText nameText;
    private String path;
    private MediaPlayer mediaPlayer;
    private SurfaceView surfaceView;
    private boolean pause;
    private int position;
    
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        mediaPlayer = new MediaPlayer();
        nameText = (EditText) this.findViewById(R.id.filename);
        surfaceView = (SurfaceView) this.findViewById(R.id.surfaceView);
        surfaceView.getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
        surfaceView.getHolder().setFixedSize(176, 144);
        surfaceView.getHolder().setKeepScreenOn(true);
        surfaceView.getHolder().addCallback(new SurfaceCallback());
    }
    
    private final class SurfaceCallback implements Callback{
		public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
		}
		public void surfaceCreated(SurfaceHolder holder) {
			if(position>0 && path!=null){
				play(position);
				position = 0;
			}
		}
		public void surfaceDestroyed(SurfaceHolder holder) {
			if(mediaPlayer.isPlaying()){
				position = mediaPlayer.getCurrentPosition();
				mediaPlayer.stop();
			}
		}
    }

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

	public void mediaplay(View v){
    	switch (v.getId()) {
		case R.id.playbutton:
			String filename = nameText.getText().toString();
			if(filename.startsWith("http")){
				path = filename;
				play(0);
			}else{
				File file = new File(Environment.getExternalStorageDirectory(), filename);
				if(file.exists()){
					path = file.getAbsolutePath();
					play(0);
				}else{
					path = null;
					Toast.makeText(this, R.string.filenoexsit, 1).show();
				}
			}
		
			break;

		case R.id.pausebutton:
			if(mediaPlayer.isPlaying()){
				mediaPlayer.pause();
				pause = true;
			}else{
				if(pause){
					mediaPlayer.start();
					pause = false;
				}
			}
			break;
			
		case R.id.resetbutton:
			if(mediaPlayer.isPlaying()){
				mediaPlayer.seekTo(0);
			}else{
				if(path!=null){
					play(0);
				}
			}
			break;
		case R.id.stopbutton:
			if(mediaPlayer.isPlaying()){
				mediaPlayer.stop();
			}
			break;
		}
    }

	private void play(int position) {
		try {
			mediaPlayer.reset();
			mediaPlayer.setDataSource(path);
			mediaPlayer.setDisplay(surfaceView.getHolder());
			mediaPlayer.prepare();//缓冲
			mediaPlayer.setOnPreparedListener(new PrepareListener(position));
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	
	private final class PrepareListener implements OnPreparedListener{
		private int position;
		
		public PrepareListener(int position) {
		     this.position = position;
		}

		public void onPrepared(MediaPlayer mp) {
			mediaPlayer.start();
			if(position>0) mediaPlayer.seekTo(position);
		}
	}
}

[sarsscofy]

楼主啊，这个问题，最后怎么解决的？

[nuist320]

引用 4 楼 fangmingshijie 的回复:

你没有监听callback。
import android.app.Activity;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnPreparedListener;
import android.os.Bundle;
import android.os.Environment;
import android.view.SurfaceHolder;
import android.view.SurfaceHolder.Callback;
import android.view.SurfaceView;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends Activity {
    private EditText nameText;
    private String path;
    private MediaPlayer mediaPlayer;
    private SurfaceView surfaceView;
    private boolean pause;
    private int position;
    
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        mediaPlayer = new MediaPlayer();
        nameText = (EditText) this.findViewById(R.id.filename);
        surfaceView = (SurfaceView) this.findViewById(R.id.surfaceView);
        surfaceView.getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
        surfaceView.getHolder().setFixedSize(176, 144);
        surfaceView.getHolder().setKeepScreenOn(true);
        surfaceView.getHolder().addCallback(new SurfaceCallback());
    }
    
    private final class SurfaceCallback implements Callback{
		public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
		}
		public void surfaceCreated(SurfaceHolder holder) {
			if(position>0 && path!=null){
				play(position);
				position = 0;
			}
		}
		public void surfaceDestroyed(SurfaceHolder holder) {
			if(mediaPlayer.isPlaying()){
				position = mediaPlayer.getCurrentPosition();
				mediaPlayer.stop();
			}
		}
    }

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

	public void mediaplay(View v){
    	switch (v.getId()) {
		case R.id.playbutton:
			String filename = nameText.getText().toString();
			if(filename.startsWith("http")){
				path = filename;
				play(0);
			}else{
				File file = new File(Environment.getExternalStorageDirectory(), filename);
				if(file.exists()){
					path = file.getAbsolutePath();
					play(0);
				}else{
					path = null;
					Toast.makeText(this, R.string.filenoexsit, 1).show();
				}
			}
		
			break;

		case R.id.pausebutton:
			if(mediaPlayer.isPlaying()){
				mediaPlayer.pause();
				pause = true;
			}else{
				if(pause){
					mediaPlayer.start();
					pause = false;
				}
			}
			break;
			
		case R.id.resetbutton:
			if(mediaPlayer.isPlaying()){
				mediaPlayer.seekTo(0);
			}else{
				if(path!=null){
					play(0);
				}
			}
			break;
		case R.id.stopbutton:
			if(mediaPlayer.isPlaying()){
				mediaPlayer.stop();
			}
			break;
		}
    }

	private void play(int position) {
		try {
			mediaPlayer.reset();
			mediaPlayer.setDataSource(path);
			mediaPlayer.setDisplay(surfaceView.getHolder());
			mediaPlayer.prepare();//缓冲
			mediaPlayer.setOnPreparedListener(new PrepareListener(position));
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	
	private final class PrepareListener implements OnPreparedListener{
		private int position;
		
		public PrepareListener(int position) {
		     this.position = position;
		}

		public void onPrepared(MediaPlayer mp) {
			mediaPlayer.start();
			if(position>0) mediaPlayer.seekTo(position);
		}
	}
}

非常感谢fangmingshijie 大牛。 帮我解决了这个问题。重点是 public void surfaceDestroyed(SurfaceHolder holder) { if(mediaPlayer.isPlaying()){ position = mediaPlayer.getCurrentPosition(); mediaPlayer.stop(); }