我尝试了很多方法，对我的代码做了很多更改，我阅读了 Android MediaPlayer 文档，我尝试了 StackOverflow 示例，但没有一个能解决我的问题。

我的问题:当我按下模拟器或手机的主页按钮然后重新打开应用程序时，它从头开始。

希望你能帮助我。提前致谢。

这是我的代码:

public class Mediaplayer extends Activity implements OnCompletionListener,
    OnErrorListener, OnInfoListener, OnPreparedListener,
    OnSeekCompleteListener, OnVideoSizeChangedListener,
    SurfaceHolder.Callback, MediaController.MediaPlayerControl {
Display currentDisplay;
SurfaceView surfaceView;
SurfaceHolder surfaceHolder;
MediaPlayer mediaPlayer;
MediaController controller;
int videoWidth = 0;
int videoHeight = 0;
boolean readyToPlay = false;
public final static String LOGTAG = "CUSTOM_VIDEO_PLAYER";

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.video);

    surfaceView = (SurfaceView) this.findViewById(R.id.SurfaceView);
    surfaceHolder = surfaceView.getHolder();
    surfaceHolder.addCallback(this);
    surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    mediaPlayer = new MediaPlayer();
    mediaPlayer.setOnCompletionListener(this);
    mediaPlayer.setOnErrorListener(this);
    mediaPlayer.setOnInfoListener(this);
    mediaPlayer.setOnPreparedListener(this);
    mediaPlayer.setOnSeekCompleteListener(this);
    mediaPlayer.setOnVideoSizeChangedListener(this);
    mediaPlayer.setWakeMode(getApplicationContext(),
            PowerManager.PARTIAL_WAKE_LOCK);
    String filePath = "http://cdn.example.com/wp-content/uploads/Almost.Human-S01E10.mp4";

    try {
        mediaPlayer.setDataSource(filePath);
    } catch (IllegalArgumentException e) {
        Log.v(LOGTAG, e.getMessage());
        finish();
    } catch (IllegalStateException e) {
        Log.v(LOGTAG, e.getMessage());
        finish();
    } catch (IOException e) {
        Log.v(LOGTAG, e.getMessage());
        finish();
    }

    controller = new MediaController(this);
    currentDisplay = getWindowManager().getDefaultDisplay();

}

public void surfaceCreated(SurfaceHolder holder) {
    // Log.v(LOGTAG, "surfaceCreated Called");

    mediaPlayer.setDisplay(holder);

    try {
        mediaPlayer.prepare();
    } catch (IllegalStateException e) {
        // Log.v(LOGTAG, e.getMessage());
        finish();
    } catch (IOException e) {
        // Log.v(LOGTAG, e.getMessage());
        finish();
    }
}

public void surfaceChanged(SurfaceHolder holder, int format, int width,
        int height) {
    Log.v(LOGTAG, "surfaceChanged Called");
}

public void surfaceDestroyed(SurfaceHolder holder) {
    Log.v(LOGTAG, "surfaceDestroyed Called");
}

public void onCompletion(MediaPlayer mp) {
    Log.v(LOGTAG, "onCompletion Called");
    finish();
}

public boolean onError(MediaPlayer mp, int whatError, int extra) {
    Log.v(LOGTAG, "onError Called");

    if (whatError == MediaPlayer.MEDIA_ERROR_SERVER_DIED) {
        Log.v(LOGTAG, "Media Error, Server Died " + extra);
    } else if (whatError == MediaPlayer.MEDIA_ERROR_UNKNOWN) {
        Log.v(LOGTAG, "Media Error, Error Unknown " + extra);
    }

    return false;
}

public boolean onInfo(MediaPlayer mp, int whatInfo, int extra) {
    if (whatInfo == MediaPlayer.MEDIA_INFO_BAD_INTERLEAVING) {
        Log.v(LOGTAG, "Media Info, Media Info Bad Interleaving " + extra);
    } else if (whatInfo == MediaPlayer.MEDIA_INFO_NOT_SEEKABLE) {
        Log.v(LOGTAG, "Media Info, Media Info Not Seekable " + extra);
    } else if (whatInfo == MediaPlayer.MEDIA_INFO_UNKNOWN) {
        Log.v(LOGTAG, "Media Info, Media Info Unknown " + extra);
    } else if (whatInfo == MediaPlayer.MEDIA_INFO_VIDEO_TRACK_LAGGING) {
        Log.v(LOGTAG, "MediaInfo, Media Info Video Track Lagging " + extra);
        /*
         * Android Version 2.0 and Higher } else if (whatInfo ==
         * MediaPlayer.MEDIA_INFO_METADATA_UPDATE) {
         * Log.v(LOGTAG,"MediaInfo, Media Info Metadata Update " + extra);
         */
    }
    return false;
}

public void onPrepared(MediaPlayer mp) {
    Log.v(LOGTAG, "onPrepared Called");
    videoWidth = mp.getVideoWidth();
    videoHeight = mp.getVideoHeight();

    if (videoWidth > currentDisplay.getWidth()
            || videoHeight > currentDisplay.getHeight()) {
        float heightRatio = (float) videoHeight
                / (float) currentDisplay.getHeight();
        float widthRatio = (float) videoWidth
                / (float) currentDisplay.getWidth();

        if (heightRatio > 1 || widthRatio > 1) {
            if (heightRatio > widthRatio) {
                videoHeight = (int) Math.ceil((float) videoHeight
                        / (float) heightRatio);
                videoWidth = (int) Math.ceil((float) videoWidth
                        / (float) heightRatio);
            } else {
                videoHeight = (int) Math.ceil((float) videoHeight
                        / (float) widthRatio);
                videoWidth = (int) Math.ceil((float) videoWidth
                        / (float) widthRatio);
            }
        }
    }

    surfaceView.setLayoutParams(new LinearLayout.LayoutParams(videoWidth,
            videoHeight));
    mp.start();

    controller.setMediaPlayer(this);
    controller.setAnchorView(this.findViewById(R.id.MainView));
    controller.setEnabled(true);
    controller.show();
}

@Override
protected void onPause() {
    super.onPause();
    if (mediaPlayer.isPlaying()) {
        mediaPlayer.pause();
    } else {
        return;
    }
}

public void onSeekComplete(MediaPlayer mp) {
    Log.v(LOGTAG, "onSeekComplete Called");
}

public void onVideoSizeChanged(MediaPlayer mp, int width, int height) {
    Log.v(LOGTAG, "onVideoSizeChanged Called");
}

public boolean canPause() {
    return true;
}

public boolean canSeekBackward() {
    return true;
}

public boolean canSeekForward() {
    return true;
}

public int getBufferPercentage() {
    return 0;
}

public int getCurrentPosition() {
    return mediaPlayer.getCurrentPosition();
}

public int getDuration() {
    return mediaPlayer.getDuration();
}

public boolean isPlaying() {
    return mediaPlayer.isPlaying();
}

public void pause() {

    mediaPlayer.pause();

}

public void seekTo(int pos) {
    mediaPlayer.seekTo(pos);
}

public void start() {
    mediaPlayer.start();
}

@Override
public boolean onTouchEvent(MotionEvent ev) {

    controller.show();

    return false;
}

@Override
public int getAudioSessionId() {
    // TODO Auto-generated method stub
    return 0;
}

 }

最佳答案

我知道你已经接受了一个答案，但我会根据你对你的问题的评论以及你和 Nana 对 Nana 的回答的评论来解释问题是什么。

1. SurfaceView 不再可见时销毁，再次可见时重新创建。
2. 您正在 Activity onPause() 方法中调用 mp.pause()。
3. 当您转到“最近”应用列表并尝试重新启动该应用时，将重新创建 SurfaceView。
4. 在 surfaceCreated 方法中调用 mp.prepare() 但是此时 mp 处于暂停状态并调用 暂停的 Mediaplayer 上的 prepare() 将抛出 IllegalStateException。
5. 您有一个 try/catch block ，它捕获 IllegalStateException 并调用 finish() - 这就是第一次尝试重新启动应用程序的原因来自“最近”列表导致 Activity 被销毁。
6. 由于上述一系列事件，您需要再次尝试从“最近”列表中重新打开应用程序，但由于 Activity 已被销毁，它将经历完整的创建过程(调用 onCreate(..)。这就是它从头开始的原因。

Nana 的回答是一种解决方法，但它仍然意味着必须尝试两次才能从“最近”列表中重新启动您的 Activity。

不幸的是，MediaPlayer 类缺少检查“状态”的方法，isPlaying 是任何状态唯一有用的方法。遗憾的是，类开发人员没有考虑添加 getState() 方法(或类似方法)来检查它是否已启动、播放、停止、暂停等。

防止 IllegalStateException 的一种方法是使用一个名为 isPaused 的 bool 值(例如)，然后修改您的 Activity onPause ()如下...

if (mediaPlayer.isPlaying()) {
    mediaPlayer.pause();
    isPaused = true;
}

...并且在 surfaceCreated(...)...

try {
    if (isPaused) {
        mpStart();
        isPaused = false;
    }
    else
        mediaPlayer.prepare();
}
// catch blocks here

关于android - 按下主页按钮并重新打开应用程序后如何在 Android 中恢复 MediaPlayer，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/23716019/