처음으로 query1.addevent 리스너가 호출되지 않습니다.

Question

firebase를 사용하여 Android 앱에서 채팅 앱을 개발해야합니다. 그룹을 탈퇴하고 참여할 수있는 여러 그룹으로 구성되어 있습니다. 처음에는 그룹에 참여하고 참여하지 않은 그룹이 표시되지 않습니다. 두 번째로 목록보기를 스크롤하거나보기를 변경하면 올바르게 표시됩니다. 문제를 친절하게 해결해야하며 아래의 코드를 살펴보고 어떤 문제를 수정해야하는지 보여줍니다.

public class Allgroups extends AppCompatActivity { 
    private DatabaseReference mDatabaseRef; 
    private List<ImageUpload> imgList; 
    private List<groupuserstoken> imgList1; 
    ListView listView; 
    private ImageListAdapter adapter; 
    private DatabaseReference databaseReference; 
    ProgressDialog progressDialog; 


    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_allgroups); 
     progressDialog = new ProgressDialog(this); 
     progressDialog.setMessage("Please wait loading groups..."); 

     listView=(ListView)findViewById(R.id.allgroups11); 
     mDatabaseRef = FirebaseDatabase.getInstance().getReference(); 
     imgList=new ArrayList<>(); 
     final Query query = mDatabaseRef.child("Groups"); 
     listView.smoothScrollByOffset(10); 
     query.addValueEventListener(new ValueEventListener() { 
      @Override 
      public void onDataChange(DataSnapshot dataSnapshot) { 
       for (DataSnapshot snapshot : dataSnapshot.getChildren()) { 
        ImageUpload img = snapshot.getValue(ImageUpload.class); 
        imgList.add(img); 
       } 

       adapter = new ImageListAdapter(Allgroups.this, R.layout.custommenu, imgList); 
       adapter.notifyDataSetChanged(); 
       listView.setAdapter(adapter); 
      } 
      @Override 
      public void onCancelled(DatabaseError databaseError) { 

      } 
     }); 
     listView.setOnItemClickListener(new AdapterView.OnItemClickListener() { 
      @Override 
      public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) { 
       String name=imgList.get(i).getName(); 
       String path=imgList.get(i).getUrl(); 
       String topic=imgList.get(i).getTopic(); 
       Intent intent= new Intent(getApplicationContext(),Main4Activity.class); 
       intent.putExtra("name",name); 
       intent.putExtra("path",path); 
       intent.putExtra("topic",topic); 
       startActivity(intent); 
      } 
     }); 
    } 
} 




public class ImageListAdapter extends ArrayAdapter<ImageUpload> { 
     private Activity context; 
     private int resource; 
     private List<ImageUpload> listImage; 

     private DatabaseReference mDatabaseRef; 
     private List<groupuserstoken> imgList1; 
     ProgressDialog progressDialog; 
     int pos; 




     public ImageListAdapter(@NonNull Activity context, @LayoutRes int resource, @NonNull List<ImageUpload> objects) { 
      super(context, resource, objects); 
      this.context = context; 
      this.resource = resource; 
      listImage = objects; 
     } 


      TextView tvName; 
       TextView tvDes; 
      TextView statuss; 
      Button leave; 
      ImageView img; 





     @NonNull 
     @Override 
     public View getView(final int position, @Nullable View convertView, @NonNull ViewGroup parent) { 

      View v = convertView; 

      if (v == null) { 
       LayoutInflater vi; 
       vi = LayoutInflater.from(getContext()); 
       v = vi.inflate(R.layout.custommenu, null); 
      } 
      // final LayoutInflater inflater = context.getLayoutInflater(); 
     // v = LayoutInflater.from(getContext()).inflate(R.layout.custommenu, parent, false); 

      ImageUpload listImage1 = getItem(position); 

      if (listImage1 !=null) { 


       tvName = (TextView) v.findViewById(R.id.as); 
       tvDes = (TextView) v.findViewById(R.id.aa); 
       statuss = (TextView) v.findViewById(R.id.users); 
       img = (ImageView) v.findViewById(R.id.addgroup1); 
       leave = (Button) v.findViewById(R.id.leavegroup); 

       mDatabaseRef = FirebaseDatabase.getInstance().getReference(); 
       final String name = listImage.get(pos).getName(); 
       final Query query1 = mDatabaseRef.child(name + "user"); 
       query1.addValueEventListener(new ValueEventListener() { 
        @Override 
        public void onDataChange(DataSnapshot dataSnapshot) { 

         imgList1 = new ArrayList<>(); 
         for (DataSnapshot snapshot : dataSnapshot.getChildren()) { 
          groupuserstoken img = snapshot.getValue(groupuserstoken.class); 
          imgList1.add(img); 
         } 
         String token = FirebaseInstanceId.getInstance().getToken(); 
         if (!(imgList1.isEmpty())) { 

          if (!(imgList1.contains(token))) { 
           leave.setText("Leave Group"); 
          } 
         } 


        } 

        @Override 
        public void onCancelled(DatabaseError databaseError) { 


        } 
       }); 

       tvName.setText(listImage1.getName()); 
       tvDes.setText(listImage1.getDescription()); 
       statuss.setText(listImage1.getMembers() + " Users "); 
       Glide.with(context).load(listImage1.getUrl()).into(img); 
      } 


      leave.setOnClickListener(new View.OnClickListener() { 
       @Override 
       public void onClick(View v) { 
        String groupname = listImage.get(position).getName(); 
        mDatabaseRef = FirebaseDatabase.getInstance().getReference().child(groupname+"user").child(FirebaseInstanceId.getInstance().getToken()); 
        mDatabaseRef.child("token").setValue(FirebaseInstanceId.getInstance().getToken()); 
       } 
      }); 
      return v; 
     } 
    } 

Answer 1

어댑터에 setTag() 및 getTag()를 사용하지만, 더 나은 연습 RecyclerView 대신 ListView을 사용하는 것입니다하시기 바랍니다.