Question

我收到此错误：

04-17 09:35:10.227: E/AndroidRuntime(9377): java.lang.RuntimeException: Error receiving broadcast Intent { act=com.aldakur.instalacionesdep.services.action.FIN flg=0x10 } in com.aldakur.instalacionesdep.info.RssAvisosFragment$ProgressReceiver@42721b68
04-17 09:35:10.227: E/AndroidRuntime(9377):     at android.app.LoadedApk$ReceiverDispatcher$Args.run(LoadedApk.java:776)
04-17 09:35:10.227: E/AndroidRuntime(9377):     at android.os.Handler.handleCallback(Handler.java:733)
04-17 09:35:10.227: E/AndroidRuntime(9377):     at android.os.Handler.dispatchMessage(Handler.java:95)
04-17 09:35:10.227: E/AndroidRuntime(9377):     at android.os.Looper.loop(Looper.java:136)
04-17 09:35:10.227: E/AndroidRuntime(9377):     at android.app.ActivityThread.main(ActivityThread.java:5146)
04-17 09:35:10.227: E/AndroidRuntime(9377):     at java.lang.reflect.Method.invokeNative(Native Method)
04-17 09:35:10.227: E/AndroidRuntime(9377):     at java.lang.reflect.Method.invoke(Method.java:515)
04-17 09:35:10.227: E/AndroidRuntime(9377):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:732)
04-17 09:35:10.227: E/AndroidRuntime(9377):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:566)
04-17 09:35:10.227: E/AndroidRuntime(9377):     at dalvik.system.NativeStart.main(Native Method)
04-17 09:35:10.227: E/AndroidRuntime(9377): Caused by: java.lang.NullPointerException
04-17 09:35:10.227: E/AndroidRuntime(9377):     at com.aldakur.instalacionesdep.info.RssAvisosFragment$ProgressReceiver.onReceive(RssAvisosFragment.java:123)
04-17 09:35:10.227: E/AndroidRuntime(9377):     at android.app.LoadedApk$ReceiverDispatcher$Args.run(LoadedApk.java:766)

这是我的片段代码。

onCreateView方法：

    @Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    View view = inflater.inflate(R.layout.rss_avisos, container, false);

    ListView lv = (ListView)view.findViewById(R.id.rss_avisos_lv);
    lv.setOnItemClickListener(this);

    if(isMyServiceRunning()){

        pDialog3 = new ProgressDialog(getActivity());
        pDialog3.setMessage("3.Cargando Noticias...");
        pDialog3.setCancelable(false);
        pDialog3.setProgressStyle(ProgressDialog.STYLE_SPINNER);
        pDialog3.show();


        }

        IntentFilter filter = new IntentFilter();
        filter.addAction(CheckNuevosAvisosIntentService.ACTION_PROGRESO);
        filter.addAction(CheckNuevosAvisosIntentService.ACTION_FIN);
        getActivity().registerReceiver(rcv, filter);
        AvisosEnListaAdapter adapter = new AvisosEnListaAdapter(getActivity(), avisosList);
        lv.setAdapter(adapter);
    return view;
}

我的BroadCastReceiver：

    public class ProgressReceiver extends BroadcastReceiver {

    //ProgressDialog pDialog2 = new ProgressDialog(RssAvisosActivity.this);

    @Override
    public void onReceive(Context context, Intent intent) {

        if(intent.getAction().equals(CheckNuevosAvisosIntentService.ACTION_PROGRESO)) {
            int prog = intent.getIntExtra("progreso", 0);

            if(!pDialog3.isShowing()){
            pDialog3.setMessage("2.Cargando Noticias...");
            pDialog3.setCancelable(false);//erabiltzaileak atzera botoia sakatuz ez kantzelatzeko
            pDialog3.setProgressStyle(ProgressDialog.STYLE_SPINNER);
            pDialog3.show();

            }

        }
        else if(intent.getAction().equals(CheckNuevosAvisosIntentService.ACTION_FIN)) {

            //Select
            DataBaseHelper myDB = new DataBaseHelper(getActivity().getBaseContext());
            myDB.openDataBase();
            avisosList = myDB.getAllAvisos("eu");
            AvisosEnListaAdapter adapter = new AvisosEnListaAdapter(getActivity(), avisosList);
            lv.setAdapter(adapter);

            if(pDialog3.isShowing()){
                pDialog3.dismiss();
        }
        }
    }

}

我认为getActivity.unregisterReceiver（rcv）可能是解决方案但不知道在哪里写。在活动中，此代码将写入onPause。

在哪里为Fragment编写相同的代码？

谢谢。

Answer 1

我认为您在尝试getActivity()的行中尝试了NullPointerException。所以我认为你是以错误的方式注册/取消注册接收器。您应该在onResume注册并在onPause取消注册，如下所示：

@Override
public void onResume() {
    super.onResume();
    IntentFilter filter = new IntentFilter();
    filter.addAction(CheckNuevosAvisosIntentService.ACTION_PROGRESO);
    filter.addAction(CheckNuevosAvisosIntentService.ACTION_FIN);
    getActivity().registerReceiver(rcv, filter);
}

@Override
public void onPause() {
    super.onPause();
    getActivity().unregisterReceiver(rcv);
}

此外，请不要忘记从getActivity().registerReceiver(rcv, filter);方法中删除此行onCreateView()。并且当您收到ACTION_FIN操作时，根据logcat异常显示，因此我强烈建议您在isAdded()子句中添加if条件，以确保该片段附加到活动：

    else if(intent.getAction().equals(CheckNuevosAvisosIntentService.ACTION_FIN) 
        && isAdded()) {
        // your code here
    }

Answer 2

在显示对话框之前在onReceive()中添加行：

  @Override
        public void onReceive(Context context, Intent intent) {               
        if(intent.getAction().equals(CheckNuevosAvisosIntentService.ACTION_PROGRESO)) {
                int prog = intent.getIntExtra("progreso", 0);
                pDialog3 = new ProgressDialog(getActivity());    // this line will prevent NPE
                if(!pDialog3.isShowing()){
                    pDialog3.setMessage("2.Cargando Noticias...");
                    pDialog3.setCancelable(false);//erabiltzaileak atzera botoia sakatuz ez kantzelatzeko
                    pDialog3.setProgressStyle(ProgressDialog.STYLE_SPINNER);
                    pDialog3.show();
                }
           }

它将pDialog3设为NULL并抛出空指针异常

Answer 3

在BroadcastReceiver中使用Fragment的大多数情况下，BroadcastReceiver在onStart中注册，在onStop中未注册。建议BroadcastReceiver和onStart注册和取消注册onStop的位置。因为在Activity的生命周期内，onStart之后调用onCreate而onStop之前调用onDestroy，而通常在onCreate中初始化小部件但onDestroy不能总是及时执行。 Fragment的生命周期依赖于Activity的生命周期。

Fragment中的“接收广播意图错误”

3 个答案: