リストビューでFirebaseを使用すると1行しか表示されない

Question

これはおそらくここでのいくつかの質問と重複していることは知っていますが、ちょっと、それらの解決策は機能していません。だから私は本当に提案が必要です。 firebaseを使用してlistviewを管理しようとしましたが、役に立たないです。 私はいくつかのチュートリアルを試しましたが、誰も私の問題を解決していません。 Firebaseから移入しようとしているlistviewがあります。 custom adapterを作成し、そこにchildEventListenersを追加しました。最後に私はにadapterを添付します。 firebasedatabaseにいくつかの項目がありますが、最後のものだけがlistviewに表示されています。これらの項目をすべて表示したいと考えています。

public abstract class FireBaseListAdapter extends ArrayAdapter<SaleModel> { 

    Activity activity; 
    // Setup our Firebase mFirebaseRef 
    DatabaseReference mRef; 
    private SaleModel model; 
    private String mUsername; 
    private LayoutInflater mInflater; 
    private List<SaleModel> mModels; 
    private List<String> mKeys; 
    private ChildEventListener mListener; 
    private ViewGroup viewGroup; 
    private LinearLayout wrapper; 

    public FireBaseListAdapter(DatabaseReference mRef, Activity activity) { 
     super(activity, android.R.layout.simple_list_item_1); 
     this.activity = activity; 
     this.mRef = mRef; 
     this.mUsername = mUsername; 

     mInflater = activity.getLayoutInflater(); 
     mModels = new ArrayList<SaleModel>(); 
     mKeys = new ArrayList<String>(); 


     // Look for all child events. We will then map them to our own internal ArrayList, which backs ListView 
     mListener = this.mRef.addChildEventListener(new ChildEventListener() { 
      @Override 
      public void onChildAdded(DataSnapshot dataSnapshot, String previousChildName) { 

       Map<String, Object> newPost = 
         (Map<String, Object>) dataSnapshot.getValue(); 
       model = new SaleModel(newPost.get("name").toString(), 
         newPost.get("attendant_name").toString(), 
         newPost.get("created_at").toString()); 
       String key = dataSnapshot.getKey(); 

       // Insert into the correct location, based on previousChildName 
       if (previousChildName == null) { 
        mModels.add(0, model); 
        mKeys.add(0, key); 

       } else { 
        int previousIndex = mKeys.indexOf(previousChildName); 
        int nextIndex = previousIndex + 1; 
        if (nextIndex == mModels.size()) { 
         mModels.add(model); 
         mKeys.add(key); 

        } else { 
         mModels.add(nextIndex, model); 
         mKeys.add(nextIndex, key); 
         //showNotification(model); 
        } 
       } 

       notifyDataSetChanged(); 
      } 

      @Override 
      public void onChildChanged(DataSnapshot dataSnapshot, String s) { 
       // One of the mModels changed. Replace it in our list and name mapping 
       String key = dataSnapshot.getKey(); 
       Map<String, Object> newPost = 
         (Map<String, Object>) dataSnapshot.getValue(); 

       SaleModel newModel = new SaleModel(newPost.get("message").toString(), newPost.get("author").toString(), newPost.get("created_at").toString()); 
       int index = mKeys.indexOf(key); 

       mModels.set(index, newModel); 

       notifyDataSetChanged(); 
      } 

      @Override 
      public void onChildRemoved(DataSnapshot dataSnapshot) { 

       // A model was removed from the list. Remove it from our list and the name mapping 
       String key = dataSnapshot.getKey(); 
       int index = mKeys.indexOf(key); 

       mKeys.remove(index); 
       mModels.remove(index); 

       notifyDataSetChanged(); 
      } 

      @Override 
      public void onChildMoved(DataSnapshot dataSnapshot, String previousChildName) { 

       // A model changed position in the list. Update our list accordingly 
       String key = dataSnapshot.getKey(); 
       Map<String, Object> newPost = 
         (Map<String, Object>) dataSnapshot.getValue(); 

       SaleModel newModel = new SaleModel(newPost.get("message").toString(), newPost.get("author").toString(), newPost.get("created_at").toString()); 
       int index = mKeys.indexOf(key); 
       mModels.remove(index); 
       mKeys.remove(index); 
       if (previousChildName == null) { 
        mModels.add(0, newModel); 
        mKeys.add(0, key); 
       } else { 
        int previousIndex = mKeys.indexOf(previousChildName); 
        int nextIndex = previousIndex + 1; 
        if (nextIndex == mModels.size()) { 
         mModels.add(newModel); 
         mKeys.add(key); 
        } else { 
         mModels.add(nextIndex, newModel); 
         mKeys.add(nextIndex, key); 
        } 
       } 
       notifyDataSetChanged(); 
      } 

      @Override 
      public void onCancelled(DatabaseError databaseError) { 
       Log.e("FireBaseListAdapter", "Listen was cancelled, no more updates will occur"); 

      } 


     }); 
    } 

    public void cleanup() { 
     // We're being destroyed, let go of our mListener and forget about all of the mModels 
     mRef.removeEventListener(mListener); 
     mModels.clear(); 
     mKeys.clear(); 
    } 

    @Override 
    public int getCount() { 
     return mModels.size(); 
    } 

    @Override 
    public SaleModel getItem(int i) { 
     return mModels.get(i); 
    } 

    @Override 
    public long getItemId(int i) { 
     return i; 
    } 

    @Override 
    public View getView(int position, View convertView, ViewGroup parent) { 
     View row = convertView; 
     SaleModel comment = getItem(position); 

     int type = getItemViewType(position); 

     // Map a Chat object to an entry in our listview 
     String author = comment.getName(); 
     String attendant_name = comment.getAttendant_name(); 
     String created_at = comment.getCreated_at(); 

     // If the message was sent by this user, color it differently 
     LayoutInflater inflater = (LayoutInflater) this.getContext().getSystemService 
       (this.activity.getApplicationContext().LAYOUT_INFLATER_SERVICE); 

     row = inflater.inflate(R.layout.itemview, parent, false); 
     ((TextView) row.findViewById(R.id.attname)).setText(attendant_name); 
     ((TextView) row.findViewById(R.id.c_name)).setText(author); 
     ((TextView) row.findViewById(R.id.updated_at)).setText(created_at); 

     return row; 

    } 
} 

SaleModel.java：

public class SaleModel { 
    //obviously there's a lot of things i'm not using here, so ignore these 
    String id, business_id, attendant_id, attendant_name, product_id, 
      customer_id, customer_first_name, code, 
      customer_last_name, customer_image, uid, 
      reader_id, price, quantity, name, image, 
      created_at, deleted_at, offlineTag, updated_at, svg; 
public SaleModel() { 
    } 

    public SaleModel(String name, String attendant_name, String created_at) { 
     this.name = name; 
     this.attendant_name = attendant_name; 
     this.created_at = created_at; 
    } 
//getters and setters 
public String getAttendant_name() { 
     return attendant_name; 
    } 

    public void setAttendant_name(String attendant_name) { 
     this.attendant_name = attendant_name; 
    } 
public String getName() { 
     return name; 
    } 

    public void setName(String name) { 
     this.name = name; 
    } 
    public String getCreated_at() { 
     return created_at; 
    } 

    public void setCreated_at(String created_at) { 
     this.created_at = created_at; 
    }} 

そして、これは私が私のフラグメントでそれを使用している方法です：

FireBaseListAdapter.java

@Override 
    public void onStart() { 
     super.onStart(); 
    FirebaseDatabase ref = FirebaseDatabase.getInstance().getReference().child("sales"); 
     setUpAdapter(); 
     final FireBaseListAdapter mChatListAdapter = new FireBaseListAdapter(ref, parentActivity) { 
      @Override 
      public void cleanup() { 
       super.cleanup(); 
      } 
     }; 
     listView.setAdapter(mChatListAdapter); 
     mChatListAdapter.registerDataSetObserver(new DataSetObserver() { 
      @Override 
      public void onChanged() { 
       super.onChanged(); 
       listView.setSelection(mChatListAdapter.getCount() - 1); 
      } 
     }); 

    } 

そして例の私のデータ構造：

{ 
    "-KMjcAb5O2MOx_WrofUT" : { 
    "attendant_id" : "93", 
    "business_id" : "9", 
    "code" : "9.146860413464", 
    "created_at" : "2016-07-15 08:32:10", 
    "customer_first_name" : "Unidentified", 
    "customer_id" : "10", 
    "customer_last_name" : "", 
    "image" : "", 
    "name" : "Black Forest Cake 2kg", 
    "price" : "3500.0", 
    "product_id" : "59", 
    "quantity" : "1", 
    "reader_id" : "93", 
    "uid" : "" 
    }, 
    "-KMjcAb8EQi3ujTpoJG1" : { 
    "attendant_id" : "93", 
    "business_id" : "9", 
    "code" : "9.146860413465", 
    "created_at" : "2016-07-15 08:32:10", 
    "customer_first_name" : "Unidentified", 
    "customer_id" : "10", 
    "customer_last_name" : "", 
    "image" : "", 
    "name" : "Black Forest Cake 2kg", 
    "price" : "3500.0", 
    "product_id" : "59", 
    "quantity" : "1", 
    "reader_id" : "93", 
    "uid" : "" 
    }} 

Answer 1

コードのこのセクションを以下のようにループする必要があります。これがあなたを助けることを願っています

Map < String, Object > newPost = 
    (Map < String, Object >) dataSnapshot.getValue(); 
for (Object posts: newPost.values()) { 
    Map < String, Object > postMap = (Map < String, Object >) posts; 
    model = new SaleModel(postMap.get("name").toString(), 
    postMap.get("attendant_name").toString(), 
    postMap.get("created_at").toString()); 
    String key = dataSnapshot.getKey(); 

    // Insert into the correct location, based on previousChildName 
    if (previousChildName == null) { 
    mModels.add(0, model); 
    mKeys.add(0, key); 

    } else { 
    int previousIndex = mKeys.indexOf(previousChildName); 
    int nextIndex = previousIndex + 1; 
    if (nextIndex == mModels.size()) { 
     mModels.add(model); 
     mKeys.add(key); 

    } else { 
     mModels.add(nextIndex, model); 
     mKeys.add(nextIndex, key); 
     //showNotification(model); 
    } 
    } 
}