相关疑难解决方法(0)

我正在实现与获取当前音乐曲目信息相关的应用程序.

我使用以下代码来获取:

public class CurrentMusicTrackInfoActivity extends Activity {

    public static final String SERVICECMD = "com.android.music.musicservicecommand";

    @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", …

我在The method getSystemService(String) is undefined for the type WebAppInterface 使用“getSystemService”时遇到了这个错误。我在接口类工作，而不是在活动类工作。

 @JavascriptInterface
public void Viber(String value ) {
    if (value.equals("on")) {
        // Get instance of Vibrator from current Context
        Vibrator v = (Vibrator)getSystemService(mContext.VIBRATOR_SERVICE);

        // Vibrate for 300 milliseconds
        v.vibrate(300);
    }

}