Android中如何实现RecyclerView点击条目弹出Toast展示点击内容

方案一：直接在Adapter内部处理（最简实现，适合仅需要Toast的场景） #

仅需修改MainAdapter.java中myViewHolder的构造方法，新增条目点击/触摸监听即可：

class myViewHolder extends RecyclerView.ViewHolder{
    CircleImageView img;
    TextView name, course, email;

    public myViewHolder(@NonNull View itemView)
    {
        super(itemView);

        img = (CircleImageView)itemView.findViewById(R.id.img1);
        name = (TextView)itemView.findViewById(R.id.nametext);
        course = (TextView)itemView.findViewById(R.id.coursetext);
        email = (TextView)itemView.findViewById(R.id.emailtext);

        // 点击事件触发Toast
        itemView.setOnClickListener(v -> {
            int position = getBindingAdapterPosition();
            // 避免条目已被移除时点击触发崩溃
            if (position != RecyclerView.NO_POSITION) {
                MainModel clickedItem = getItem(position);
                // 可自定义Toast展示的字段内容
                String showContent = "点击条目：" + clickedItem.getName() + "\n课程：" + clickedItem.getCourse();
                Toast.makeText(v.getContext(), showContent, Toast.LENGTH_SHORT).show();
            }
        });

        // 若需要触摸触发Toast，注释上方点击事件，启用下方代码即可
        /*
        itemView.setOnTouchListener((v, event) -> {
            if (event.getAction() == MotionEvent.ACTION_UP) {
                int position = getBindingAdapterPosition();
                if (position != RecyclerView.NO_POSITION) {
                    MainModel clickedItem = getItem(position);
                    String showContent = "触摸条目：" + clickedItem.getName() + "\n邮箱：" + clickedItem.getEmail();
                    Toast.makeText(v.getContext(), showContent, Toast.LENGTH_SHORT).show();
                }
                return true;
            }
            return false;
        });
        */
    }
}

方案二：接口回调到Activity处理（适合后续需要扩展点击逻辑的场景） #

如果后续点击条目需要做跳转页面、请求接口等更复杂的操作，推荐用接口回调把事件传到Activity处理：

1. 先在MainAdapter.java中定义回调接口

public class MainAdapter extends FirebaseRecyclerAdapter<MainModel, MainAdapter.myViewHolder> {
    // 新增条目点击回调接口
    public interface OnItemClickListener {
        void onItemClick(MainModel item, int position);
    }
    private OnItemClickListener mListener;
    // 暴露设置监听器的方法给外部调用
    public void setOnItemClickListener(OnItemClickListener listener) {
        this.mListener = listener;
    }

    // 原有其他代码保持不变...
}

2. 修改myViewHolder构造方法中的点击逻辑，回调给外部监听器

class myViewHolder extends RecyclerView.ViewHolder{
    CircleImageView img;
    TextView name, course, email;

    public myViewHolder(@NonNull View itemView)
    {
        super(itemView);
        img = (CircleImageView)itemView.findViewById(R.id.img1);
        name = (TextView)itemView.findViewById(R.id.nametext);
        course = (TextView)itemView.findViewById(R.id.coursetext);
        email = (TextView)itemView.findViewById(R.id.emailtext);

        itemView.setOnClickListener(v -> {
            int position = getBindingAdapterPosition();
            if (position != RecyclerView.NO_POSITION && mListener != null) {
                mListener.onItemClick(getItem(position), position);
            }
        });
    }
}

3. 在MainActivity.java中设置监听器，处理点击事件弹出Toast

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    recyclerView = (RecyclerView)findViewById(R.id.rv);
    recyclerView.setLayoutManager(new LinearLayoutManager(this));

    FirebaseRecyclerOptions<MainModel> options =
            new FirebaseRecyclerOptions.Builder<MainModel>()
                    .setQuery(FirebaseDatabase.getInstance().getReference().child("students"), MainModel.class)
                    .build();

    mainAdapter = new MainAdapter(options);
    recyclerView.setAdapter(mainAdapter);

    // 新增条目点击监听
    mainAdapter.setOnItemClickListener((item, position) -> {
        String showContent = "点击了第" + (position+1) + "个学生：" + item.getName();
        Toast.makeText(MainActivity.this, showContent, Toast.LENGTH_SHORT).show();
    });
}

注意事项 #

• 使用getBindingAdapterPosition()而非废弃的getPosition()，可以避免数据刷新时位置匹配错误
• 所有点击逻辑都加了position != RecyclerView.NO_POSITION的判断，避免条目被移除时点击触发空指针崩溃

内容的提问来源于stack exchange，提问作者Isaac Darlong