接續到上一篇的RecyclerView，今天要來分享一下點擊事件

首先是Adapter的部分

先創立一個interface接口

    void onItemClick(int position);
}

接著去設定一個變數引用他

private OnItemClickListener listener;

創建一個呼叫他的方法

public void setOnItemClickListener(OnItemClickListener listener) {
    this.listener = listener;
}

然後到原本的viewholder去設定

itemView.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            if (listener != null) {
                int position = getAdapterPosition();
                if (position != RecyclerView.NO_POSITION) {
                    listener.onItemClick(position);
                }
            }
        }
    });

主程式

接著回到主程式就可以調用了

myAdapter.setOnItemClickListener(new MyAdapter.OnItemClickListener() {
            @Override
            public void onItemClick(int position) {
                String itemNumber = dataList.get(position).get("num");
                Toast.makeText(MainActivity.this,"點擊了" + itemNumber + "號",Toast.LENGTH_SHORT).show();
            }
        });

Adatper的完整程式碼

package com.example.itdemo;

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.ArrayList;
import java.util.HashMap;

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> {
    private ArrayList<HashMap<String,String>> dataList;
    private OnItemClickListener listener;
    public MyAdapter(ArrayList<HashMap<String,String>> dataList) {
        this.dataList = dataList;
    }

    @NonNull
    @Override
    public MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        // 創建 ViewHolder 並連結項目佈局檔案
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item, parent, false);
        return new MyViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull MyAdapter.MyViewHolder holder, int position) {
        // 在這裡綁定數據到 ViewHolder 的 View
        String itemView = String.valueOf(dataList.get(position));
        holder.textView.setText(dataList.get(position).get("num"));
        holder.textView5.setText(dataList.get(position).get("score"));

    }

    @Override
    public int getItemCount() {
        return dataList.size();
    }
    public void setOnItemClickListener(OnItemClickListener listener) {
        this.listener = listener;
    }

    public class MyViewHolder extends RecyclerView.ViewHolder {
        private TextView textView;
        private TextView textView5;

        public MyViewHolder(@NonNull View itemView) {
            super(itemView);
            textView = itemView.findViewById(R.id.textView);
            textView5 = itemView.findViewById(R.id.textView5);
            itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    if(listener != null){
                        int position = getAdapterPosition();
                        if (position != RecyclerView.NO_POSITION){
                            listener.onItemClick(position);
                        }
                    }
                }
            });
        }
    }
    public interface OnItemClickListener {
        void onItemClick(int position);
    }
}

成果如下