将数据从服务传递到片段，给出空点

Question

我正在尝试使用 BroadcastReceiver 从服务中获取数据，并且我能够在日志中显示该数据，但是当我尝试像这样使用 Bundle 发送数据时

 @Override
protected void onStart() {
    myReceiver = new MainActivity.MyReceiver();
    IntentFilter intentFilter = new IntentFilter();
    intentFilter.addAction(MediaService.MY_ACTION);
    registerReceiver(myReceiver, intentFilter);
    super.onStart();
}

private class MyReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context arg0, Intent arg1) {
        // TODO Auto-generated method stub

        String datapa = arg1.getStringExtra("DATAPASSED");
        String datap2 = arg1.getStringExtra("ALBUM_DATA");
        Log.d("TITLE OF SONG",datapa);
        Log.d("ALBUM",datap2);



            Bundle bundle = new Bundle();
            bundle.putString("Title",datapa);
            bundle.putString("album", datap2);
            Songs someFragment = new Songs();
            someFragment.setArguments(bundle);


    }

}

并像这样获取数据

   String strtext = getArguments().getString("album");
        if (strtext!=null){
            textView.setText(strtext);
        }else {
            textView.setText(String.valueOf(songarr.size()));
        }
 String title = getArguments().getString("Title");
    if (title!=null){
        textView.setText(title);
    }else {
        textView.setText("Total Songs");
    }

我收到错误

 java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.os.Bundle.getString(java.lang.String)' on a null object reference
                  at beatbox.neelay.anotherbeat.Fragment.Songs.onCreateView(Songs.java:55)
                  at android.support.v4.app.Fragment.performCreateView(Fragment.java:2184)
                  at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1298)
                  at android.support.v4.app.FragmentManagerImpl.moveFragmentsToInvisible(FragmentManager.java:2323)
                  at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2136)
                  at android.support.v4.app.FragmentManagerImpl.optimizeAndExecuteOps(FragmentManager.java:2092)
                  at android.support.v4.app.FragmentManagerImpl.execSingleAction(FragmentManager.java:1969)
                  at android.support.v4.app.BackStackRecord.commitNowAllowingStateLoss(BackStackRecord.java:620)
                  at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:143)
                  at com.antonyt.infiniteviewpager.InfinitePagerAdapter.finishUpdate(InfinitePagerAdapter.java:67)
                  at android.support.v4.view.ViewPager.populate(ViewPager.java:1268)
                  at android.support.v4.view.ViewPager.populate(ViewPager.java:1116)
                  at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1642)
                  at android.view.View.measure(View.java:18811)
                  at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:716)
                  at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:462)
                  at android.view.View.measure(View.java:18811)
                  at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5952)
                  at android.support.design.widget.CoordinatorLayout.onMeasureChild(CoordinatorLayout.java:714)
                  at android.support.design.widget.CoordinatorLayout.onMeasure(CoordinatorLayout.java:786)
                  at android.view.View.measure(View.java:18811)
                  at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5952)
                  at android.widget.FrameLayout.onMeasure(FrameLayout.java:194)
                  at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:139)
                  at android.view.View.measure(View.java:18811)
                  at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5952)
                  at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1465)
                  at android.widget.LinearLayout.measureVertical(LinearLayout.java:748)
                  at android.widget.LinearLayout.onMeasure(LinearLayout.java:630)
                  at android.view.View.measure(View.java:18811)
                  at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5952)
                  at android.widget.FrameLayout.onMeasure(FrameLayout.java:194)
                  at android.view.View.measure(View.java:18811)
                  at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5952)
                  at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1465)
                  at android.widget.LinearLayout.measureVertical(LinearLayout.java:748)
                  at android.widget.LinearLayout.onMeasure(LinearLayout.java:630)
                  at android.view.View.measure(View.java:18811)
                  at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5952)
                  at android.widget.FrameLayout.onMeasure(FrameLayout.java:194)
                  at com.android.internal.policy.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2645)
                  at android.view.View.measure(View.java:18811)
                  at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2127)
                  at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1243)
                  at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1479)
                  at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1134)
                  at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6045)
                  at android.view.Choreographer$CallbackRecord.run(Choreographer.java:860)
                  at android.view.Choreographer.doCallbacks(Choreographer.java:672)
                  at android.view.Choreographer.doFrame(Choreographer.java:608)
                  at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:846)
                  at android.os.Handler.handleCallback(Handler.java:739)
                  at android.os.Handler.dispatchMessage(Handler.java:95)
                at android.os.Looper.loop(Loop

问题是我正在服务中播放歌曲，所以当用户单击按钮时，服务会将当前播放的歌曲数据发送到 activity，然后从 activity 发送到片段，何时这首歌没有播放它只会显示整首歌但是当我运行应用程序崩溃时说空字符串但我正在设置 else 语句他们我做错了什么？？任何提示都会有帮助。在用户单击主要内容列表之前，片段不会获取数据。Using the same bundle way i am able to send the data to other fragment 这里的初始值为 null 我该如何解决这个问题。

Answer 1

先看看你的getArguments是否不为null

if(getArguments() !=null ) // 然后做你正在做的事情，即从 bundle 中拉出字符串。

Answer 2

我没有间接传递数据，而是使用直接方式，我在服务中这样设置

 Intent intent = new Intent();
    intent.setAction(MY_ACTION);

    intent.putExtra("DATAPASSED", activeAudio.getTitle());
    intent.putExtra("ALBUM_DATA",activeAudio.getAlbum());
    sendBroadcast(intent);

在我的片段中

 @Override
public void onStart() {
    super.onStart();


    myReceiver = new MyReceiver();
    IntentFilter intentFilter = new IntentFilter();
    intentFilter.addAction(MediaService.MY_ACTION);
    getActivity().registerReceiver(myReceiver, intentFilter);

}

private class MyReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context arg0, Intent arg1) {
        // TODO Auto-generated method stub

        String datapa = arg1.getStringExtra("DATAPASSED");
        String datap2 = arg1.getStringExtra("ALBUM_DATA");
        Log.d("TITLE OF SONG", datapa);
        Log.d("ALBUM", datap2);
        textView.setText(datapa);
        textView1.setText(datap2);
    }

}

希望这对某些人有所帮助。

将数据从服务传递到片段，给出空点

passing data from service to fragment giving null point

android

bundle

android-fragments

android-broadcastreceiver