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java - Android Studio上的ToDo List-无法解决方法

问题描述

我在创建任务时遇到问题，我在其中长按将删除的项目。我不确定如何解决这个问题。显然，这应该在那里，我已经宣布了。检查我评论的地方。OnItemLongClicked 未被识别。那就是我遇到麻烦的地方。我是新手，所以请帮忙！

package com.example.mysimpletodo;

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;

import java.util.List;

public class itemsAdapter extends RecyclerView.Adapter<itemsAdapter.ViewHolder> {

    public interface onLongClickListener {
        void onItemLongClicked(int position);


    }

    List<String> items;
    View.OnLongClickListener longClickListener;

    public itemsAdapter(List<String> items, View.OnLongClickListener longClickListener) {
        this.items = items;
        this.longClickListener = longClickListener;
    }

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


        View todoView = LayoutInflater.from(parent.getContext()).inflate(android.R.layout.simple_list_item_1, parent, false);
        return new ViewHolder(todoView);
    }

    @Override
    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {

        String item = items.get(position);
        holder.bind(item);

    }

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

    class ViewHolder extends RecyclerView.ViewHolder{

        TextView tvItem;

        public ViewHolder(@NonNull View itemView) {
            super(itemView);
            tvItem = itemView.findViewById(android.R.id.text1);

        }

        public void bind(String item) {
            tvItem.setText(item);
            tvItem.setOnLongClickListener(new View.OnLongClickListener() {
                @Override
                public boolean onLongClick(View v) {

                    longClickListener.OnItemLongClicked(getAdapterPosition());
                            //check for this line again. I have a problem here where OnItemLongClicked is not recognized and stays red. How come it is not recognizing it and it's recognized above.

                    return true;

                }
            });
        }
    }
}

标签： javaandroidruntime-error

解决方案

将您的绑定方法签名更改为：

public void bind(String item, final LongClickListener longClickListener) {
        tvItem.setText(item);
        tvItem.setOnLongClickListener(new View.OnLongClickListener() {
            @Override
            public boolean onLongClick(View v) {

                longClickListener.onItemLongClicked(getAdapterPosition());

                return true;

            }
        });
    }

如果您没有在某处传递它，您的 ViewHolder 类不知道您声明的 longClickListener。

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