FirebaseRecyclerAdapter multiple viewHolder

• Z时代
• 2024-01-10
• 分类：问答

我试图使用FirebaseRecyclerAdapter与RecyclerView来显示不同类型的项目。特别是用户对特定股票的股票交易。按照我的理解，我已经扩展了FirebaseRecyclerAdapter，但它不起作用。以下是代码：FirebaseRecyclerAdapter multiple viewHolder

public abstract class StockTransactionFirebaseRecyclerAdapter extends 
     FirebaseRecyclerAdapter<StockTransactionType, TransactionViewHolder> 
     implements ListenerInterface 
{ 
    private static final String TAG = "StockTxnAdapter"; 
    private DatabaseReference mFirebaseDatabaseReference; 
    private FirebaseListenerManager mFirebaseListenerManager; 
    private String mUserId; 
    public StockTransactionFirebaseRecyclerAdapter (Query ref, DatabaseReference databaseReference, 
                String userId) 
    { 
     // The layout portfolio_buy_transaction_item is just a dummy since we are 
     // inflating our own layouts when required. 
     super (StockTransactionType.class, R.layout.portfolio_buy_transaction_item, 
       TransactionViewHolder.class, ref); 
     mFirebaseDatabaseReference = databaseReference; 
     mFirebaseListenerManager = new FirebaseListenerManager(); 
     mUserId = userId; 
     Log.e (TAG, "Inside StockTransactionFirebaseRecyclerAdapter"); 
    } 
    @Override 
    public int getItemViewType (int position) 
    { 
     StockTransactionType stockTransactionType = getItem (position); 
     Log.e (TAG, "Inside getItemViewType (" + position + "): " + stockTransactionType.returnType()); 
     return stockTransactionType.returnType(); 
    } 
    @Override 
    public TransactionViewHolder onCreateViewHolder (ViewGroup parent, int viewType) 
    { 
     Log.e (TAG, "onCreateViewHolder for " + viewType); 
     View itemView; 
     switch (viewType) 
     { 
      case StockTransactionType.TRANSACTION_TYPE_BUY: 
       itemView = LayoutInflater.from (parent.getContext()) 
         .inflate (R.layout.portfolio_buy_transaction_item, parent, false); 
       return new BuyTransactionViewHolder (itemView); 
      case StockTransactionType.TRANSACTION_TYPE_SELL: 
       itemView = LayoutInflater.from (parent.getContext()) 
         .inflate (R.layout.portfolio_sell_transaction_item, parent, false); 
       return new SellTransactionViewHolder (itemView); 
      case StockTransactionType.TRANSACTION_TYPE_DIVIDEND: 
       itemView = LayoutInflater.from (parent.getContext()) 
         .inflate (R.layout.portfolio_dividend_transaction_item, parent, false); 
       return new DividendTransactionViewHolder (itemView); 
      case StockTransactionType.TRANSACTION_TYPE_SPLIT: 
       itemView = LayoutInflater.from (parent.getContext()) 
         .inflate (R.layout.portfolio_split_transaction_item, parent, false); 
       return new SplitTransactionViewHolder (itemView); 
     } 
     throw new IllegalStateException ("Invalid transaction type: " + viewType); 
    } 
    @Override 
    protected void populateViewHolder (final TransactionViewHolder viewHolder, 
             StockTransactionType stockTransactionType, int position) 
    { 
     final String transactionId = this.getRef (position).getKey(); 
     final Class transaction; 
     final String location; 
     Log.e (TAG, "populateViewHolder: " + stockTransactionType.getClass().getName() + " " 
       + position); 
     switch (stockTransactionType.returnType()) 
     { 
      case StockTransactionType.TRANSACTION_TYPE_BUY: 
       transaction = BuyStockTransaction.class; 
       location = FirebaseDatabaseUtil.CHILD_TRANSACTIONS_BUY; 
       break; 
      case StockTransactionType.TRANSACTION_TYPE_SELL: 
       transaction = SellStockTransaction.class; 
       location = FirebaseDatabaseUtil.CHILD_TRANSACTIONS_SELL; 
       break; 
      case StockTransactionType.TRANSACTION_TYPE_SPLIT: 
       transaction = SplitStockTransaction.class; 
       location = FirebaseDatabaseUtil.CHILD_TRANSACTIONS_SPLIT; 
       break; 
      case StockTransactionType.TRANSACTION_TYPE_DIVIDEND: 
       transaction = DividendStockTransaction.class; 
       location = FirebaseDatabaseUtil.CHILD_TRANSACTIONS_DIVIDEND; 
       break; 
      default: 
       throw new IllegalStateException ("Invalid transaction type: " 
         + stockTransactionType.renameTypeString()); 
     } 
     DatabaseReference databaseReference = mFirebaseDatabaseReference 
       .child (location).child (mUserId).child (transactionId); 
     ValueEventListener valueEventListener = databaseReference 
       .addValueEventListener (new ValueEventListener() 
       { 
        @Override 
        public void onDataChange (DataSnapshot dataSnapshot) 
        { 
         StockTransaction stockTransaction = (StockTransaction) dataSnapshot.getValue (transaction); 
         viewHolder.assignViewHolder (stockTransaction); 
        } 
        @Override 
        public void onCancelled (DatabaseError databaseError) 
        { 
         if (getActivity() instanceof MainActivity) 
         { 
          MainActivity mainActivity = (MainActivity) getActivity(); 
          mainActivity.showDatabaseError (TAG, Thread.currentThread() 
            .getStackTrace(), databaseError); 
         } 
        } 
       }); 
     mFirebaseListenerManager.addListner (databaseReference, valueEventListener); 
    } 
    protected abstract Activity getActivity(); 
    @Override 
    public void removeAllListeners() 
    { 
     mFirebaseListenerManager.removeAllListners(); 
    } 
} 

BuyTransactionViewHolder，SellTransactionViewHolder等都是TransactionViewHolder子类，并且，BuyStockTransaction，SellStockTransaction等都是StockTransaction子类。

除了构造函数，甚至没有函数被调用。由于我对android编程新手可能会做些傻事。有人能帮助我理解我做错了什么吗？

编辑

这是怎么了初始化适配器：

final DatabaseReference databaseReference = mFirebaseDatabaseReference 
      .child (FirebaseDatabaseUtil.CHILD_USER_STOCK_TRANSACTIONS) 
      .child (mUserId).child (mStockId); 
mStockTransactionFirebaseRecyclerAdapter = new StockTransactionFirebaseRecyclerAdapter (
     databaseReference, mFirebaseDatabaseReference, mUserId) 
{ 
    @Override 
    protected Activity getActivity() 
    { 
     return StockDisplayFragment.this.getActivity(); 
    } 
}; 

我希望我没有错过了一些东西，这清除所有的疑虑。但如果它不，我会很乐意添加更多的信息。

回答：

以上是 FirebaseRecyclerAdapter multiple viewHolder 的全部内容， 来源链接： utcz.com/qa/265053.html