RecyclerView onItemClick 不起作用，始终显示 nullpointerexception

Question

我检查了整个 Whosebug，但找不到解决方案，可能这是重复的问题，但请帮助我。我在适配器中创建接口：-

public interface OnItemClickListener {
    void onItemClick(int positon, AdvSearchList_Model item, View view);
}
public MyMatches_New_Adapter(Context context, ArrayList<AdvSearchList_Model> dataList, OnItemClickListener listener) {
    this.context = context;
    this.listItem = dataList;
    this.listener = listener;
}

在 onBindViewHolder 中：-

final AdvSearchList_Model item = listItem.get(position);
        myholder.setIsRecyclable(false);
        myholder.bind(position, item, listener);

调用绑定函数：-

public void bind(final int position, final AdvSearchList_Model item, final MyMatches_New_Adapter.OnItemClickListener listener) {
                itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    listener.onItemClick(position, item, v);
                }
            });
            user_pic_circle_layout.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    listener.onItemClick(position, item, v);
                }
            });}

并在 Fragment 中设置 onItemClick Class:-

adapter1 = new MyMatches_New_Adapter(context, listItem, new MyMatches_New_Adapter.OnItemClickListener() {
        @Override
        public void onItemClick(int positon, final AdvSearchList_Model item, View view) {
            switch (view.getId()) {
                case R.id.user_pic_circle_layout:
                    Toast.makeText(context, "COMMENT Working", Toast.LENGTH_SHORT).show();
                    break;
            }
        }
    });

当我单击 Item 时，它会给我 NullPointerException。请做有需要的。

Answer 1

在你的适配器中添加这个方法 -

 public void setOnItemListener(Context context, ArrayList<AdvSearchList_Model> dataList, OnItemClickListener listener) {    
    this.context = context;
    this.listItem = dataList;
    this.listener = listener;
 }

访问您的片段 -

adapter1.setOnItemListener(context, listItem, new MyMatches_New_Adapter.OnItemClickListener() {
        @Override
        public void onItemClick(int positon, final AdvSearchList_Model item, View view) {
            switch (view.getId()) {
                case R.id.user_pic_circle_layout:
                    Toast.makeText(context, "COMMENT Working", Toast.LENGTH_SHORT).show();
                    break;
            }
        }
    });

Answer 2

您必须将适配器 class 中的上下文向下转换为您的侦听器字段，而不是将侦听器从外部 class 传递给您的适配器，在 try catch 中这样做：

    private Context mContext;
    private OnItemClickListener mListener;
    public MyMatches_New_Adapter(Context context, ArrayList<AdvSearchList_Model> dataList) {
       this.mContext = context;
       this.listItem = dataList;
        try {
               this.mListener = (OnItemClickListener ) context;
      } catch (ClassCastException e) {
               throw new ClassCastException(context.toString() +  
          " must implement OnItemClickListener ");
      }

 }

您必须在 activity 中像回调一样实现此接口如果不起作用请尝试此操作，请告诉我们更多详细信息。

RecyclerView onItemClick 不起作用，始终显示 nullpointerexception

RecyclerView onItemClick not working, always show nullpointerexception

android

android-recyclerview

onitemclicklistener

onitemclick