Android Studio實現幀動畫

<?xml version="1.0" encoding="utf-8"?>
//幀動畫資源列表控件
<animation-list xmlns:android="http://schemas.android.com/apk/res/android">
  //第一個是圖片資源的地址；第二參數是這個圖片播放的事件：120ms；
    <item android:drawable="@drawable/boy_0" android:duration="120"/>
    <item android:drawable="@drawable/boy_1" android:duration="120"/>
    <item android:drawable="@drawable/boy_2" android:duration="120"/>
    <item android:drawable="@drawable/boy_3" android:duration="120"/>
    <item android:drawable="@drawable/boy_4" android:duration="120"/>
    <item android:drawable="@drawable/boy_5" android:duration="120"/>
    <item android:drawable="@drawable/boy_6" android:duration="120"/>
    <item android:drawable="@drawable/boy_7" android:duration="120"/>
</animation-list>

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    android:id="@+id/boy"
    android:background="@drawable/cartoon"(背景為資源整合佈局文件)
    android:layout_height="match_parent"
    android:layout_width="match_parent"
    xmlns:android="http://schemas.android.com/apk/res/android"/>

package com.example.imageview;

import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
import androidx.core.app.NotificationCompat;

import android.annotation.SuppressLint;
import android.app.AlertDialog;
import android.app.Notification;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.DialogInterface;
import android.content.Intent;
import android.graphics.BitmapFactory;
import android.graphics.Color;
import android.graphics.drawable.AnimationDrawable;
import android.graphics.drawable.Drawable;
import android.os.Build;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.ListView;
import android.widget.PopupWindow;
import android.widget.ProgressBar;
import android.widget.RelativeLayout;
import android.widget.TextView;

import java.nio.channels.Channel;
import java.util.ArrayList;
import java.util.List;

public class MainActivity<i> extends AppCompatActivity {
    /*
    private static final String TAG = "leo";
    private NotificationManager manager;
    private Notification notification;
    private PopupWindow popupWindow;
    //創建一個數組，內部元素為Bean類型；
    private List<Bean> data = new ArrayList<>();
     */
    private boolean flag = true;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.cartoon_boy);
        //獲得佈局
        RelativeLayout relativeLayout = findViewById(R.id.boy);
        //從佈局中獲得背景
        AnimationDrawable anim = (AnimationDrawable)relativeLayout.getBackground();
        //設置點擊監聽
        relativeLayout.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if (flag){
                    anim.start();
                    flag = false;
                }
                else{
                    anim.stop();
                    flag = true;
                }
            }
        });
}