他のクラス内のフラグメントのTextViewを更新するには

Question

私のRecyclerViewをクリックして、フラグメント内のTextViewを更新しようとしています。コンテキストを渡してみましたが、コンテキストを使用するとボタンをクリックするとアプリがクラッシュしました。私にそれを手伝ってください。ここで

は私RecyclerAdapterです。ここ

public class CartRecycleAdapter extends RecyclerView.Adapter<CartRecycleAdapter.RecycleViewHolder> { 

private ArrayList<CartDataProvider> arraylist = new ArrayList<>(); 
Context CTX; 
public CartRecycleAdapter(ArrayList<CartDataProvider> arraylist, Context ctx){ 
    this.arraylist = arraylist; 
    this.CTX = ctx.getApplicationContext(); 
} 

@Override 
public RecycleViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { 

    View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.modelcart, parent,false); 
    RecycleViewHolder recycleViewHolder = new RecycleViewHolder(view); 
    return recycleViewHolder; 
} 
@Override 
public void onBindViewHolder(final RecycleViewHolder holder, int position) { 

    final CartDataProvider homeCycleDataProvider = arraylist.get(position); 

    holder.ItemImage.setImageResource(R.drawable.placeholder); 
    holder.TXV_ItemName.setText(homeCycleDataProvider.getItemName().toString()); 
    holder.TXV_PastPrice.setText(String.valueOf(homeCycleDataProvider.getPastPrice()).toString()); 
    holder.TXV_FixedPrice.setText(String.valueOf(homeCycleDataProvider.getFixedPrice()).toString()); 
    holder.TXV_Quantity.setText(Integer.valueOf(homeCycleDataProvider.getQuantity()).toString()); 
    holder.ratingBar.setRating(homeCycleDataProvider.getRating()); 

    holder.BTN_QuantityPlus.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      int x = holder.getAdapterPosition(); 
      CartDataProvider homeCycleDataProvider = arraylist.get(x); 
      int quantity = homeCycleDataProvider.getQuantity(); 

      homeCycleDataProvider.setQuantity(++quantity); 
      holder.TXV_Quantity.setText(String.valueOf(homeCycleDataProvider.getQuantity())); 
      TextView textView = (TextView) ((MainActivity)CTX).findViewById(R.id.txt_total_amount); 
      textView.setText("ok"); 
     } 
    }); 
    holder.BTN_QuantityMinus.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 

      int x = holder.getAdapterPosition(); 
      CartDataProvider homeCycleDataProvider = arraylist.get(x); 
      int quantity = homeCycleDataProvider.getQuantity(); 

      if(quantity != 0){ 
       homeCycleDataProvider.setQuantity(--quantity); 
       holder.TXV_Quantity.setText(String.valueOf(homeCycleDataProvider.getQuantity())); 
       TextView textView = (TextView) ((MainActivity)CTX).findViewById(R.id.txt_total_amount); 
       textView.setText("ok"); 

      } 

     } 
    }); 
} 

@Override 
public int getItemCount() { 
    return arraylist.size(); 
} 

public static class RecycleViewHolder extends RecyclerView.ViewHolder{ 

    ImageView ItemImage; 
    TextView TXV_ItemName, TXV_PastPrice, TXV_FixedPrice, TXV_Percentage,TXV_Quantity; 
    ImageButton BTN_QuantityMinus, BTN_QuantityPlus; 
    RatingBar ratingBar; 


    public RecycleViewHolder(View view){ 

     super(view); 

     ItemImage = (ImageView) view.findViewById(R.id.item_image); 
     TXV_ItemName = (TextView) view.findViewById(R.id.item_name); 
     TXV_PastPrice = (TextView) view.findViewById(R.id.past_price); 
     TXV_FixedPrice = (TextView) view.findViewById(R.id.fixed_price); 
     TXV_Percentage = (TextView) view.findViewById(R.id.percentiage); 
     ratingBar = (RatingBar) view.findViewById(R.id.ratingBar); 
     TXV_Quantity = (TextView) view.findViewById(R.id.txv_quantity); 
     BTN_QuantityMinus = (ImageButton) view.findViewById(R.id.quantity_minus); 
     BTN_QuantityPlus = (ImageButton) view.findViewById(R.id.quantity_plus); 

    } 
} 

は私のFragment.java

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, 
         Bundle savedInstanceState) { 
    // Inflate the layout for this fragment 
    View view = inflater.inflate(R.layout.fragment_cart, container, false); 

    TXT_TotalAmout = (TextView) view.findViewById(R.id.txt_total_amount); 
    TXT_Quantity = (TextView) view.findViewById(R.id.txv_quantity); 

    CartItemRecyclerView = (RecyclerView) view.findViewById(R.id.item_recycler_id); 

    int i =0; 
    for (String name : itemname){ 

     CartDataProvider cartDataProvider = new CartDataProvider(itemname[i], imageurl[i], 
       rating[i],pastprice[i],fixedprice[i],Quantity); 

     arrayList.add(cartDataProvider); 

     TotalPrice += fixedprice[i]; 
     i++; 
    } 

    adapter = new CartRecycleAdapter(arrayList,getContext()); 
    CartItemRecyclerView.setHasFixedSize(true); 
    layoutManager = new LinearLayoutManager(getActivity()); 
    CartItemRecyclerView.setLayoutManager(layoutManager); 
    CartItemRecyclerView.setAdapter(adapter); 
    CartItemRecyclerView.setNestedScrollingEnabled(false); 

    return view; 
} 

Answer 1

があなたのFragment Class

あなた Recycler view

で今

public static TextView TXT_TotalAmout, TXT_Quantity; 

であなたのtextviewstaticとして宣言しています

MyFragClass.TXT_TotalAmount.setText("Your Amount"); 
MyFragClass.TXT_Quantity.setText("Your Amount");