使RecyclerView可点击不起作用

Question

我一直在努力使我的RecyclerView列表可以点击。我还没有成功从点击中检索任何结果。我搜索了stackoverflow和youtube，但没有理解我实现的错误。我的适配器是

食物适配器

ublic class FoodAdapter extends RecyclerView.Adapter<FoodAdapter.FoodViewHolder> {

private Context mCtx;
private List<Food> foodList;

public FoodAdapter(Context mCtx, List<Food> foodList) {
    this.mCtx = mCtx;
    this.foodList = foodList;
}


@Override
public FoodViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    LayoutInflater inflater = LayoutInflater.from(mCtx);
    View view = inflater.inflate(R.layout.list_item, null);

    FoodViewHolder foodView = new FoodViewHolder(view, mCtx, foodList);

    return foodView;
}

@Override
public void onBindViewHolder(FoodViewHolder holder, int position) {
    Food food = foodList.get(position);
    holder.txtFoodTitle.setText(food.getFoodTitle());
    holder.txtFoodDesc.setText(food.getFoodDesc());
    holder.txtFoodLoc.setText(food.getFoodLoc() + ", CA");
    holder.txtFoodAuthor.setText(food.getFoodAuthor());
    holder.imageView.setImageDrawable(mCtx.getResources().getDrawable(food.getImage(), null));
}

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

class FoodViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
    ImageView imageView;
    TextView txtFoodTitle, txtFoodDesc, txtFoodLoc, txtFoodAuthor;
    List<Food> foods;
    Context ctx;

    public FoodViewHolder(View itemView, Context ctx, List<Food> foods) {
        super(itemView);

        itemView.setOnClickListener(this);
        this.ctx = ctx;
        this.foods = foods;
        imageView = itemView.findViewById(R.id.foodImg);
        txtFoodTitle = itemView.findViewById(R.id.foodTitle);
        txtFoodDesc = itemView.findViewById(R.id.foodDesc);
        txtFoodLoc = itemView.findViewById(R.id.foodLoc);
        txtFoodAuthor = itemView.findViewById(R.id.foodAuthor);
    }

    @Override
    public void onClick(View view) {
        int position = getAdapterPosition();
        //Food food = this.foods.get(position);
        Log.i(TAG, "Clicked!");

    }
}
}

FragmentList

public class FragmentList extends Fragment {

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    View v = inflater.inflate(R.layout.fragment_fragment_list, container, false);
    RecyclerView recyclerView;
    final FoodAdapter adapter;

    final List<Food> foodList = new ArrayList<>();
    recyclerView = v.findViewById(R.id.recyclerView);
    recyclerView.setHasFixedSize(true);

    recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));

    adapter = new FoodAdapter(getActivity(), foodList);
    recyclerView.setAdapter(adapter);

    String url = "url";
    StringRequest sr = new StringRequest(Request.Method.POST, url, new Response.Listener<String>() {
        @Override
        public void onResponse(String response) {
            Log.i(TAG, response);
            try {
                JSONArray foodResp = new JSONArray(response);
                for (int i = 0; i < foodResp.length(); i++) {
                    JSONObject foodObj = foodResp.getJSONObject(i);
                    foodList.add(
                            new Food(
                                    foodObj.getInt("u_id"),
                                    R.drawable.ic_launcher_background,
                                    foodObj.getString("mealTitle"),
                                    foodObj.getString("mealDesc"),
                                    foodObj.getString("cityName"),
                                    foodObj.getString("userName")
                    ));
                }

                if (adapter != null) {
                    adapter.notifyDataSetChanged();
                }

            } catch (Exception e) {
                Log.i(TAG, "Error: " + e.getMessage());
            }

        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            Log.i(TAG, "err: " + error.toString());
        }
    }){
        @Override
        protected Map<String, String> getParams() throws AuthFailureError {
            Map<String, String> params = new HashMap<>();
            params.put("data", "value");

            return params;
        }
    };
    Volley.newRequestQueue(getActivity()).add(sr);

    return v;
}

我正在观看的一个原始视频显示它是使用ArrayList＆lt;＆gt;完成的，但我已经使用List设置了我的RecyclerView。我不认为那会很重要。任何意见，将不胜感激。谢谢！

Answer 1

您需要在特定元素上设置单击侦听器。 例如，如果您想在单击图像时执行某些操作，那么：

您需要致电holder.imageview.setOnClickListener(this);

试试这个!!

如果要将单击侦听器设置为整个行，则可能需要在行项的根元素上设置单击侦听器。

Answer 2

尝试在FragmentList.java。

中设置Click Listener

食物适配器

public class FoodAdapter extends RecyclerView.Adapter<FoodAdapter.FoodViewHolder> {

private Context mCtx;
private List<Food> foodList;

public FoodAdapter(Context mCtx, List<Food> foodList) {
    this.mCtx = mCtx;
    this.foodList = foodList;
}

public static class FoodViewHolder extends RecyclerView.FoodViewHolder {
    ImageView imageView;
    TextView txtFoodTitle, txtFoodDesc, txtFoodLoc, txtFoodAuthor;
    //List<Food> foods;
    //Context ctx;

    public FoodViewHolder(View v) {
        super(v);
        imageView = itemView.findViewById(R.id.foodImg);
        txtFoodTitle = itemView.findViewById(R.id.foodTitle);
        txtFoodDesc = itemView.findViewById(R.id.foodDesc);
        txtFoodLoc = itemView.findViewById(R.id.foodLoc);
        txtFoodAuthor = itemView.findViewById(R.id.foodAuthor);
    }
}

@Override
public FoodAdapter.FoodViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    LayoutInflater inflater = LayoutInflater.from(mCtx);
    View view = inflater.inflate(R.layout.list_item, parent, false);
    return FoodViewHolder(view);
}

@Override
public void onBindViewHolder(FoodViewHolder holder, int position) {
    Food food = foodList.get(position);
    holder.txtFoodTitle.setText(food.getFoodTitle());
    holder.txtFoodDesc.setText(food.getFoodDesc());
    holder.txtFoodLoc.setText(food.getFoodLoc() + ", CA");
    holder.txtFoodAuthor.setText(food.getFoodAuthor());
    holder.imageView.setImageDrawable(mCtx.getResources().getDrawable(food.getImage(), null));
}

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

}

<强> FragmentList

public class FragmentList extends Fragment {

    RecyclerView recyclerView;

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

    final List<Food> foodList = new ArrayList<>();
    recyclerView = v.findViewById(R.id.recyclerView);
    recyclerView.setHasFixedSize(true);

    recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));

    adapter = new FoodAdapter(getActivity(), foodList);
    recyclerView.setAdapter(adapter);

    String url = "url";
    StringRequest sr = new StringRequest(Request.Method.POST, url, new Response.Listener<String>() {
        @Override
        public void onResponse(String response) {
            Log.i(TAG, response);
            try {
                JSONArray foodResp = new JSONArray(response);
                for (int i = 0; i < foodResp.length(); i++) {
                    JSONObject foodObj = foodResp.getJSONObject(i);
                    foodList.add(
                            new Food(
                                    foodObj.getInt("u_id"),
                                    R.drawable.ic_launcher_background,
                                    foodObj.getString("mealTitle"),
                                    foodObj.getString("mealDesc"),
                                    foodObj.getString("cityName"),
                                    foodObj.getString("userName")
                    ));
                }

                if (adapter != null) {
                    adapter.notifyDataSetChanged();
                }

            } catch (Exception e) {
                Log.i(TAG, "Error: " + e.getMessage());
            }

        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            Log.i(TAG, "err: " + error.toString());
        }
    }){
        @Override
        protected Map<String, String> getParams() throws AuthFailureError {
            Map<String, String> params = new HashMap<>();
            params.put("data", "value");

            return params;
        }
    };
    Volley.newRequestQueue(getActivity()).add(sr);

    return v;
    }

    @Override
    public void onViewCreated(final View view, Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);

        /* --- Adding the Listener here --- */
        recyclerView.addOnItemTouchListener(new RecyclerItemClickListener(getContext(), new RecyclerItemClickListener.OnItemClickListener() {
            @Override
            public void onItemClick(View itemView, int position) {
                //Food food = this.foods.get(position);
                Log.i(TAG, "Clicked!");
            }
        }));
    }

}

这将是您的 RecyclerItemClickListener.java 文件：

public class RecyclerItemClickListener  implements RecyclerView.OnItemTouchListener {
    private OnItemClickListener mListener;
    GestureDetector mGestureDetector;


    public interface OnItemClickListener{
        void onItemClick(View view, int position);
    }


    public RecyclerItemClickListener(Context context, OnItemClickListener listener) {
        mListener = listener;
        mGestureDetector = new GestureDetector(context, new GestureDetector.SimpleOnGestureListener() {
            @Override public boolean onSingleTapUp(MotionEvent e) {
                return true;
            }
        });
    }

    @Override
    public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) {
        View childView = rv.findChildViewUnder(e.getX(),e.getY());
        if(childView != null && mListener != null && mGestureDetector.onTouchEvent(e)){
            mListener.onItemClick(childView, rv.getChildAdapterPosition(childView));
            return true;
        }
        return false;
    }

    @Override
    public void onTouchEvent(RecyclerView rv, MotionEvent e) {

    }

    @Override
    public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {

    }
}

希望它会有所帮助:)

Answer 3

处理整个项目“the viewholder”的点击次数

<强> 1。创建自定义侦听器

    public class RecyclerClickListener implements RecyclerView.OnItemTouchListener {
    private OnItemClickListener mListener;

    public interface OnItemClickListener {
        public void onItemClick(View view, int position);

        public void onLongItemClick(View view, int position);
    }

    GestureDetector mGestureDetector;

    public RecyclerClickListener(Context context, final RecyclerView recyclerView, OnItemClickListener listener) {
        mListener = listener;
        mGestureDetector = new GestureDetector(context, new GestureDetector.SimpleOnGestureListener() {
            @Override
            public boolean onSingleTapUp(MotionEvent e) {
                return true;
            }

            @Override
            public void onLongPress(MotionEvent e) {
                View child = recyclerView.findChildViewUnder(e.getX(), e.getY());
                if (child != null && mListener != null) {
                    mListener.onLongItemClick(child, recyclerView.getChildAdapterPosition(child));
                }
            }
        });
    }

    @Override
    public boolean onInterceptTouchEvent(RecyclerView view, MotionEvent e) {
        View childView = view.findChildViewUnder(e.getX(), e.getY());
        if (childView != null && mListener != null && mGestureDetector.onTouchEvent(e)) {
            mListener.onItemClick(childView, view.getChildAdapterPosition(childView));
            return true;
        }
        return false;
    }

    @Override
    public void onTouchEvent(RecyclerView view, MotionEvent motionEvent) {
    }

    @Override
    public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {
    }
}

<强> 2。在

中使用我们的监听器监听点击次数

  recyclerView.addOnItemTouchListener(
   //use getActivity() if you are using fragment instead of MyActivity.this
            new RecyclerClickListener(MyActivity.this, recyclerView, new RecyclerClickListener.OnItemClickListener() {
                @Override
                public void onItemClick(View view, int position) {
                    Food food= foodList.get(position);
                    //do whatever 

                }

                @Override
                public void onLongItemClick(View view, int position) {
                    // to be implement add to favourite
                }
            })


    );

如果您正在收听视图持有者中的特定项目。

1.在适配器内创建一个内部接口并创建它的实例。

    private OnItemClickListener mListener;
       public interface OnItemClickListener {
        void onItemClick(Food item);
        }


               //and also the constructor 
               public MyAdapter(List<Food> foodList,Context ctx,OnItemClickListener 
               listener){
          // ......
          this.mListener=mListener;
    }

2.在您的观察者类中创建setListener()方法

            public void SetListener(final Food item, final OnItemClickListener listener) {


            mButton.setOnClickListener(new View.OnClickListener() {

                @Override public void onClick(View v) {

                    listener.onItemClick(item);

                }

            });

        }

3.在你onBindView

之内

    @Override
    public void onBindViewHolder(FoodViewHolder holder, int position) { 
    //...
    viewHolder.setListener(foodList.get(position), mListener);
      }

4.包括您的活动或片段

 MyAdapter adapter=new MyAdapter(foodList,getActivity(),new MyAdapter.OnItemClickListener(){

          @Override
          public void onItemClick(Food item){


              }
          });