Question

我想使用for循环检索我的Firebase数据库的所有子级，数据将在片段中显示在recyclerview中。当我去事件片段时，应用程序崩溃，错误指出了要循环的那一行这是我的代码，

events.java （这是片段）

FirebaseDatabase.getInstance().getReference().child("Users/" + mUser.getUid() + "/Groups/RequestedGroups").addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
           for (DataSnapshot ds : dataSnapshot.getChildren()){
               value = ds.child("GroupID").getValue().toString();
               groupId.add(value);
           }
           retrieveGroups(groupId);
        }
        private void retrieveGroups(ArrayList<String> groupId) {
            if(groupId != null){
                for(String value : groupId){
                    FirebaseDatabase.getInstance().getReference().child("Events/"+value).addValueEventListener(new ValueEventListener() {
                        @Override
                        public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                            for(DataSnapshot d : dataSnapshot.getChildren()){

                                Event_Retrieve e = d.getValue(Event_Retrieve.class);   // error point out this line

                                list.add(e);
                            }
                            adapter = new MyAdapter(events.this.getActivity(),list);
                            recyclerView.setAdapter(adapter);
                        }

                        @Override
                        public void onCancelled(@NonNull DatabaseError databaseError) {
                            Toast.makeText(events.this.getActivity(), "oops", Toast.LENGTH_SHORT).show();
                        }
                    });
                }
            }
        }

Event_Retrieve .java

public class Event_Retrieve {
public String eventname;
public String eventdescription;
public String eventdate;
public String eventtime;
public String eventphotourl;
public String latitude;
public String lingitude;
public ArrayList<String> acceptedmember;
public ArrayList<String> invitedmember;

public Event_Retrieve(){

}

public Event_Retrieve(String eventname, String eventdescription, String eventdate, String eventtime, String eventphotourl, String latitude, String lingitude, ArrayList<String> acceptedmember, ArrayList<String> invitedmember) {
    this.eventname = eventname;
    this.eventdescription = eventdescription;
    this.eventdate = eventdate;
    this.eventtime = eventtime;
    this.eventphotourl = eventphotourl;
    this.latitude = latitude;
    this.lingitude = lingitude;
    this.acceptedmember = acceptedmember;
    this.invitedmember = invitedmember;
}

public String getEventname() {
    return eventname;
}

public String getEventdescription() {
    return eventdescription;
}

public String getEventdate() {
    return eventdate;
}

public String getEventtime() {
    return eventtime;
}

public String getEventphotourl() {
    return eventphotourl;
}

public String getLatitude() {
    return latitude;
}

public String getLingitude() {
    return lingitude;
}

public ArrayList<String> getAcceptedmember() {
    return acceptedmember;
}

public ArrayList<String> getInvitedmember() {
    return invitedmember;
}

}

fragment_event.xml

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/background"
tools:context=".places">

<!-- TODO: Update blank fragment layout -->
<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <TextView
        android:id="@+id/eventID"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginBottom="20dp"
        android:text="Events"
        android:textColor="#000"
        android:textSize="30sp" />

    <android.support.v7.widget.RecyclerView
        android:id="@+id/myRecyclerView"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />


</LinearLayout>

Logcat错误

E/HotwordDetector: Error at creating and/or starting hotword recognition.
java.lang.IllegalArgumentException: Invalid speaker model provided
    at com.google.speech.micro.GoogleHotwordRecognizer.nativeNew(Native Method)
    at com.google.speech.micro.GoogleHotwordRecognizer.<init>(SourceFile:6)
    at com.google.android.libraries.assistant.hotword.k.a(SourceFile:66)
    at com.google.android.libraries.assistant.hotword.k.at(SourceFile:35)
    at com.google.android.apps.gsa.voiceinteraction.hotword.a.dGU(SourceFile:48)
    at com.google.android.voiceinteraction.GsaVoiceInteractionService.dGU(SourceFile:109)
    at com.google.android.voiceinteraction.g.oa(SourceFile:13)
    at com.google.android.libraries.assistant.hotword.f.a(SourceFile:30)
    at com.google.android.libraries.assistant.hotword.g.run(Unknown Source)
    at com.google.android.libraries.gsa.runner.a.b.run(Unknown Source)
    at com.google.android.apps.gsa.shared.util.concurrent.b.cq.bsW(SourceFile:2)
    at com.google.android.apps.gsa.shared.util.concurrent.b.cp.run(SourceFile:5)
    at com.google.android.apps.gsa.shared.util.concurrent.b.i.run(Unknown Source)
    at com.google.android.apps.gsa.shared.util.concurrent.b.bs.run(SourceFile:3)
    at com.google.android.apps.gsa.shared.util.concurrent.b.bs.run(SourceFile:3)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1133)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607)
    at java.lang.Thread.run(Thread.java:760)
    at com.google.android.apps.gsa.shared.util.concurrent.b.o.run(SourceFile:6)

我的数据库结构

这是测试数据

使用for循环从Firebase数据库检索数据时出错

0 个答案: