Question

我想从List中的Firebase检索数据。为此，我创建了一个用于检索的活动和一个Retrieving类。从Firebase获取数据时，当我通过按下按钮打开Retrieve活动时，就会出现问题。它会打开一会儿，移回到上一个活动...

我在另一个项目中使用了相同的代码，因此没有任何问题。我被困住了...

这是我的Retrieve活动

public class RetrieveTourPlan extends AppCompatActivity {

ListView mylistView;
DatabaseReference db;
EditText search_edit_text;
List<ClassTourPlan> TourPlanList, totalreqSale, TouredArea, TouredCity;
String searchtext;
FirebaseUser firebaseUser;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_retrieve_tour_plan);


    mylistView = findViewById(R.id.mylisttourplan);
    search_edit_text= findViewById(R.id.etSearch);
    firebaseUser = FirebaseAuth.getInstance().getCurrentUser();

    TourPlanList = new ArrayList<>();
    totalreqSale = new ArrayList<>();
    TouredArea = new ArrayList<>();
    TouredCity = new ArrayList<>();

    db = FirebaseDatabase.getInstance().getReference("DbTourPlan");
}


@Override
protected void onStart() {
    super.onStart();
    db.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            TourPlanList.clear();

            for (DataSnapshot snapshot:dataSnapshot.getChildren()){
                ClassTourPlan classTourPlan=snapshot.getValue(ClassTourPlan.class);
                TourPlanList.add(classTourPlan);
            }

            TourPlanListClass adapter = new TourPlanListClass(RetrieveTourPlan.this, TourPlanList);
            mylistView.setAdapter(adapter);
        }

        @Override
        public void onCancelled(DatabaseError databaseError) {
        }
    });

}
}

与此类

public class TourPlanListClass extends ArrayAdapter<ClassTourPlan> {
private Activity context;
int position;
List<ClassTourPlan> tourPlanList;

public TourPlanListClass(Activity context,List<ClassTourPlan> tourPlanList){
    super(context,R.layout.mylistlayout,tourPlanList);
    this.context=context;
    this.tourPlanList=tourPlanList;
}

@NonNull
@Override
public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
    LayoutInflater inflater= context.getLayoutInflater();
    View listViewItems= inflater.inflate(R.layout.mylistlayout,null,true);

    TextView textTourId=listViewItems.findViewById(R.id.tvtourid);
    TextView textViewTotalReqSale=listViewItems.findViewById(R.id.tvtotalreqsale);
    TextView textViewTouredArea=listViewItems.findViewById(R.id.tvtouredarea);
    TextView textViewTouredCity=listViewItems.findViewById(R.id.tvtouredcity);



    ClassTourPlan strtingEndingPoint= tourPlanList.get(position);

    textTourId.setText(strtingEndingPoint.getClsTourId());
    textViewTotalReqSale.setText(strtingEndingPoint.getClstotalreqsale());
    textViewTouredArea.setText(strtingEndingPoint.getClstourarea());
    textViewTouredCity.setText(strtingEndingPoint.getClstourcity());

    return listViewItems;
}
}

我已经从Retrieve活动中删除了此代码，所以没有问题

  for (DataSnapshot snapshot:dataSnapshot.getChildren()){
                ClassTourPlan classTourPlan=snapshot.getValue(ClassTourPlan.class);
                TourPlanList.add(classTourPlan);
            }

这是规则

    {
  "rules": {
    ".read": true,
    ".write": true
  }
}

Logcat只显示

11-27 23：03：35.523 30191-30191 / com.example.medicalrepresentative.application E / HAL：负载： id = gralloc！= hmi-> id = gralloc 11-27 23：03：35.583 30191-30264 / com.example.medicalrepresentative.application E / HAL：负载： id = gralloc！= hmi-> id = gralloc 11-27 23：03：35.588 30191-30264 / com.example.medicalrepresentative.application E / HAL：负载： id = gralloc！= hmi-> id = gralloc

无法从Firebase检索数据

0 个答案: