Question

我希望在应用程序处于后台时收到音乐播放器的广播。

我找到了以下代码here:

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    IntentFilter iF = new IntentFilter();
    iF.addAction("com.android.music.metachanged");
    iF.addAction("com.android.music.playstatechanged");
    iF.addAction("com.android.music.playbackcomplete");
    iF.addAction("com.android.music.queuechanged");

    registerReceiver(mReceiver, iF);
}

private BroadcastReceiver mReceiver = new BroadcastReceiver() {

    @Override
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        String cmd = intent.getStringExtra("command");
        Log.v("tag ", action + " / " + cmd);
        String artist = intent.getStringExtra("artist");
        String album = intent.getStringExtra("album");
        String track = intent.getStringExtra("track");
        Log.v("tag", artist + ":" + album + ":" + track);
        Toast.makeText(CurrentMusicTrackInfoActivity.this, track, Toast.LENGTH_SHORT).show();
    }
};

它可以工作，但只有在活动运行时才有效。所以我试着制作一个静态广播接收器：

<receiver
    android:name=".receiver.MusicBroadcastReceiver"
    android:exported="false">
    <intent-filter>
        <action android:name="com.android.music.metachanged" />
        <action android:name="com.android.music.playstatechanged" />
        <action android:name="com.android.music.playbackcomplete" />
        <action android:name="com.android.music.queuechanged" />
    </intent-filter>
</receiver>

班级：

public class MusicBroadcastReceiver extends BroadcastReceiver {
    public MusicBroadcastReceiver() {
    }

    @Override
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        String cmd = intent.getStringExtra("command");
        Log.v("tag ", action + " / " + cmd);
        String artist = intent.getStringExtra("artist");
        String album = intent.getStringExtra("album");
        String track = intent.getStringExtra("track");
        Log.v("tag", artist + ":" + album + ":" + track);
        Toast.makeText(context, track, Toast.LENGTH_SHORT).show();
    }
}

它不起作用。我开始搜索，然后发现this question，声称上面的代码应该有用。但事实并非如此，当我开始播放音乐或跳过曲目时，不会调用onReceive。 Imust会做一些非常错误的事，但我无法弄清楚是什么。

任何帮助将不胜感激。感谢。

Answer 1

尝试设置android:exported="true"

http://developer.android.com/guide/topics/manifest/receiver-element.html

android：exports
广播接收机是否可以从其应用之外的来源接收消息 - ＆＃34; true＆＃34;如果它可以，＆＃34;假＆＃34;如果不。如果＆＃34; false＆＃34;，广播接收者可以接收的唯一消息是由具有相同用户ID的相同应用程序的组件发送的消息。

如何在应用程序未运行时使用broadcastreceiver获取当前播放音乐的信息？

1 个答案: