Question

我正在尝试使用Mediaplayer MP1 播放流式广播作为 Mediaplayer 的变量我想要播放所有Fragments应用，预计会有一个activity（ ActivityOne ）包含另一个Mediaplayer MP2 ，所以我想停止 MP1 当我进入（ ActivityOne ）activity，玩 MP2 时，以及当我从（ ActivityOne）返回时）我想恢复 MP1 ，当我点击button中存在的fragment时，我的主要问题是（ ActivityOne ）被调用} 我的代码只适用于一个方向：当我从（ ActivityOne ）活动返回时，音乐会停止。

应用程序的结构： MainAcitivty ＆gt; 片段＆gt;的 ActivityOne

MainActivity.java

MediaPlayer MP1;
boolean prepared = false;
boolean started = false;
PlayerTask playerTask;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    mediaPlayer = new MediaPlayer();
    playerTask = new PlayerTask();
    playerTask.execute(stream);
    /**/
       MusicButton = findViewById(R.id.toggleButton);
    MusicButton.setVisibility(View.INVISIBLE);
    MusicButton.setOnCheckedChangeListener(new OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            if (started && MusicButton.isChecked()) {
                started = false;
                MP1.pause();
                MusicButton.setChecked(true);
            } else {
                started = true;
                MP1.start();
                MusicButton.setChecked(false);
            }
        }
    });
}
@SuppressLint("StaticFieldLeak")
public class PlayerTask extends AsyncTask<String, Void, Boolean> {
    ProgressBar loadingRL = findViewById(R.id.progressBar);
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP) {
            AudioAttributes attribs = new AudioAttributes.Builder().setUsage(AudioAttributes.USAGE_MEDIA).setContentType(AudioAttributes.CONTENT_TYPE_MUSIC).build();
            MP1.setAudioAttributes(attribs);

        } else {
            MP1.setAudioStreamType(AudioManager.STREAM_MUSIC);
        }
        loadingRL.setVisibility(View.VISIBLE);

    }

    @Override
    protected Boolean doInBackground(String... strings) {
        try {
            MP1.setDataSource(strings[0]);
            MP1.prepare();
            prepared = true;
        } catch (IOException e) {
            e.printStackTrace();
        } catch (IllegalArgumentException e) {
            e.printStackTrace();
        } catch (IllegalStateException e) {
            e.printStackTrace();
        }
        MP1.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
            @Override
            public void onPrepared(MediaPlayer MP1) {
                MP1.start();

            }
        });
        return prepared;
    }

    @Override
    protected void onPostExecute(Boolean aBoolean) {
        super.onPostExecute(aBoolean);
        MusicButton.setVisibility(View.VISIBLE);
        MusicButton.setChecked(true);
         loadingRL.setVisibility(View.VISIBLE);
}

ActivityOne.java

    MediaPlayer MP2;
    boolean prepared = false;
    boolean started = false;
    ToggleButton music;
    PlayerTask playerTask = null;
    CoordinatorLayout coordinatorLayout;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_pop_for_ringtone);
        coordinatorLayout = findViewById(R.id.coord);
        MP2 = new MediaPlayer();
        playerTask = new PlayerTask();
        playerTask.execute(url);
}
  @SuppressLint("StaticFieldLeak")
    public class PlayerTask extends AsyncTask<String, Void, Boolean> {
        ProgressBar pb = findViewById(R.id.progress);

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP) {
                AudioAttributes attribs = new AudioAttributes.Builder().setUsage(AudioAttributes.USAGE_MEDIA).setContentType(AudioAttributes.CONTENT_TYPE_MUSIC).build();
                MP2.setAudioAttributes(attribs);

            } else {
                MP2.setAudioStreamType(AudioManager.STREAM_MUSIC);
            }
        }

        @Override
        protected Boolean doInBackground(String... strings) {
            if (!isCancelled()) {
                try {
                    MP2.setDataSource(strings[0]);
                    MP2.prepare();
                    prepared = true;
                } catch (IOException e) {
                    e.printStackTrace();
                } catch (IllegalArgumentException e) {
                    e.printStackTrace();
                } catch (IllegalStateException e) {
                    e.printStackTrace();
                }
                MP2.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
                    @Override
                    public void onPrepared(MediaPlayer MP2) {
                        MP2.start();
                    }
                });

            }
            return prepared;
        }

        @Override
        protected void onPostExecute(Boolean aBoolean) {
            super.onPostExecute(aBoolean);
            music.setEnabled(true);
            music.setVisibility(View.VISIBLE);
            music.setChecked(true);
            all.setVisibility(View.VISIBLE);
        }

        @Override
        protected void onCancelled(Boolean aBoolean) {
            if (isCancelled() && MP2.isPlaying()) {
                MP2.stop();
            }
        }
    }

 @Override
    public void onBackPressed() {
        if (playerTask != null && playerTask.getStatus() == AsyncTask.Status.FINISHED) {
            if (MP2.isPlaying()) {
                MP2.stop();
            }
        } else if (playerTask != null && playerTask.getStatus() != AsyncTask.Status.FINISHED) {
            playerTask.cancel(true);
        }
        super.onBackPressed();
    }

我花了2天的时间来解决这个问题而没有任何结果，请有人帮助我，我会感激他

Answer 1

您是否尝试过使用startActivityForResult（）？

Answer 2

您可以使用Otto库来解决此问题。首先创建一个新的Java课程，但选择enum代替enum，然后在public enum PlaybackEvent { PLAY, PAUSE }内添加：PLAY和PAUSE，例如：

Application

然后，如果您没有使用自定义Application类，请创建一个并在override方法中扩展onCreate和app gradle。在compile 'com.squareup:otto:1.3.8'添加Bus内，然后在Application类中创建public class MApplication extends Application { public static Bus sBus = new Bus(ThreadEnforcer.MAIN); @Override public void onCreate() { super.onCreate(); sBus.register(this); }的实例并注册。例如，这将是这样的：

<application
        android:name="com.packagename.MApplication"

不要忘记在清单默认应用程序类中替换您的新应用程序类

MainActivity

在override班onResume之后，在onPause和@Override protected void onResume() { super.onResume(); try { MApplication.sBus.register(this); } catch(Exception e){ e.printStackTrace(); } } @Override protected void onDestroy() { super.onDestroy(); try { MApplication.sBus.unregister(this); } catch(Exception e){ e.printStackTrace(); } }注册/取消注册您的活动总线。

MainActivity

在public void之后创建PlayBackEvent方法作为参数Subscribe和fragment传递，以便您可以收听将从@Subscribe public void handlePlaybackEvent(PlaybackEvent event) { switch (event) { case PLAY: if(MP1.isPlaying()) MP1.pause(); break; case PAUSE: if(!MP1.isPlaying()) MP1.play(); break; } }发送的消息类。例如：

fragment

你要做的最后一件事是在开始第二项活动时从你的MApplication.sBus.post(PlaybackEvent.PAUSE);发送信息，这将是：

overriding onBackPressed

当然你也可以发送一条消息，让第二个活动MApplication.sBus.post(PlaybackEvent.PLAY);的MP1再次播放到内线代码：

@HostListener("window:resize", ["$event"])
onResize(event) {
    // some code
}

希望这可以帮助您解决问题。

停止/启动其他活动的媒体播放器

2 个答案: