[移动开发]给recycleview中每个子项添加水波纹效果并且长按出现弹出菜单

1. 水波纹效果
   参考 https://blog.csdn.net/REIGE/article/details/68957994

recycler_item_selector.xml文件

<?xml version="1.0" encoding="utf-8"?>
<ripple xmlns:android="http://schemas.android.com/apk/res/android" android:color="@color/design_default_color_primary">
    <item android:drawable="@color/white" />
</ripple>

chat_item.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="70dp"
    android:background="@drawable/recycler_item_selector">

    <ImageView
        android:id="@+id/chat_image"
        android:layout_width="40dp"
        android:layout_height="50dp"
        android:layout_margin="10dp"
        android:scaleType="fitCenter"
        android:src="@drawable/ic_launcher_background"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/chat_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="10dp"
        android:layout_marginTop="10dp"
        android:gravity="top"
        android:text="Name"
        android:textSize="18sp"
        app:layout_constraintLeft_toRightOf="@id/chat_image"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/tx_LastText"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="10dp"
        android:text="hint"
        app:layout_constraintLeft_toRightOf="@id/chat_image"
        app:layout_constraintTop_toBottomOf="@id/chat_name" />


    <View
        android:layout_width="match_parent"
        android:layout_height="1dp"
        android:background="@color/black"
        app:layout_constraintBottom_toBottomOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

3. 长按
   菜单使用popup菜单，在Android开发者手册中看到弹出菜单popup。于是百度查询 Recycleview popup
   便找到以下结果
   https://blog.csdn.net/qq_27494201/article/details/99709433

public void showPopup(View v) {
        PopupMenu popup = new PopupMenu(context, v);
        MenuInflater inflater = popup.getMenuInflater();
        inflater.inflate(R.menu.context_menu, popup.getMenu());
        popup.show();
    }

import android.content.Context;
import android.view.LayoutInflater;
import android.view.MenuInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

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

import com.junhaodev.mywechat.BaseApplication;
import com.junhaodev.mywechat.R;

import java.util.List;

public class ChatListAdapter extends RecyclerView.Adapter<ChatListAdapter.ViewHolder> {
    private List<ChatItem> list;
    private Context context;

    ChatListAdapter() {
        list = null;
        context = BaseApplication.getContext();
    }

    ChatListAdapter(List<ChatItem> list) {
        this(BaseApplication.getContext(), list);
    }

    ChatListAdapter(Context context, List<ChatItem> list) {
        this.context = context;
        this.list = list;
    }

    public void setList(List<ChatItem> list) {
        this.list = list;
    }

    @NonNull
    @Override
    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.chat_item,
                parent,
                false);
        view.setOnLongClickListener(new View.OnLongClickListener() {
            @Override
            public boolean onLongClick(View v) {
                showPopup(v);
                return true;
            }
        });
        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
        ChatItem item = list.get(position);
        holder.tx_name.setText(item.getName());
        holder.tx_name.setOnLongClickListener(new View.OnLongClickListener() {
            @Override
            public boolean onLongClick(View v) {
                showPopup(holder.tx_name);
                return true;
            }
        });
    }

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

    static class ViewHolder extends RecyclerView.ViewHolder {
        private final TextView tx_name;

        public ViewHolder(@NonNull View itemView) {
            super(itemView);
            tx_name = itemView.findViewById(R.id.chat_name);
        }
    }

    public void showPopup(View v) {
        PopupMenu popup = new PopupMenu(context, v);
        MenuInflater inflater = popup.getMenuInflater();
        inflater.inflate(R.menu.context_menu, popup.getMenu());
        popup.show();
    }

    public interface OnRvItemClick {
        void onItemClick(View v, int position);
    }

}