我正在尝试使用 Mediaplayer 播放流广播，并将 MP1 作为 Mediaplayer 的变量，我想在所有 Fragments 应用程序中播放它，预计有一个 activity (ActivityOne) 包含另一个要播放的 Mediaplayer MP2，所以我想在以下情况下停止 MP1我在 (ActivityOne) activity 中，并播放 MP2 ，当我从 (ActivityOne) 返回时，我想恢复 MP1，我的大问题是当我单击 fragment 中存在的 button 时调用 (ActivityOne)
我下面的代码仅适用于一个方向:
当我从 (ActivityOne) Activity 返回时，音乐停止。
应用程序的结构:MainAcitivty> Fragment> 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();
}
我花了两天时间解决这个问题，但没有任何结果，请有人帮助我，我会很感激他
最佳答案
您可以使用Otto来解决这个问题图书馆。首先新建Java类但选择 enum相反，在里面enum您可以添加:播放和暂停例如:
public enum PlaybackEvent {
PLAY, PAUSE
}
那么如果您没有使用自定义 Application类创建一个并扩展 Application和override里面onCreate方法。在你的app gradle里面添加compile 'com.squareup:otto:1.3.8'然后创建 Bus 的实例里面Application上课并注册。例如，这看起来像这样:
public class MApplication extends Application {
public static Bus sBus = new Bus(ThreadEnforcer.MAIN);
@Override
public void onCreate() {
super.onCreate();
sBus.register(this);
}
不要忘记将 list 中的默认应用程序类替换为新的应用程序类
<application
android:name="com.packagename.MApplication"
之后在您的MainActivity中类override并在 onResume 中注册/取消注册您的事件总线并在 onPause 。
@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();
}
}
之后在 MainActivity创建 public void作为参数传递的方法 PlayBackEvent和Subscribe这样您就可以收听从您的 fragment 发送的消息类(class)。例如:
@Subscribe
public void handlePlaybackEvent(PlaybackEvent event) {
switch (event) {
case PLAY:
if(MP1.isPlaying())
MP1.pause();
break;
case PAUSE:
if(!MP1.isPlaying())
MP1.play();
break;
}
}
您要做的最后一件事就是从您的 fragment 发送消息当开始第二个 Activity 时，将会发生:
MApplication.sBus.post(PlaybackEvent.PAUSE);
当然，您也可以发送消息以再次播放第二个 Activity 中的 MP1 overriding onBackPressed放入代码行:
MApplication.sBus.post(PlaybackEvent.PLAY);
希望这能帮助您解决问题。
关于java - 从另一个 Activity 停止/启动媒体播放器，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/48174613/