帧动画概念

在Android中，帧动画的本质是把一组预先准备好的图片循环切换播放，造成一种动画效果。

帧动画实现

实现帧动画有两种方式，即xml和java

方法1：xml实现帧动画

第一步：导入帧动画素材

把准备的素材放到drawable目录

第二步：创建帧动画文件

在drawable目录下创建一个animation_flower.xml的文件，往文件中添加

<?xml version="1.0" encoding="utf-8"?> <animation-list xmlns:android="https://schemas.android.com/apk/res/android"     android:oneshot="false">// 是否只播放一次 false 循环播放 <item         android:drawable="@drawable/img01"         android:duration="200" /> <item         android:drawable="@drawable/img02"         android:duration="200" /> <item         android:drawable="@drawable/img03"         android:duration="200" /> <item         android:drawable="@drawable/img04"         android:duration="200" /> <item         android:drawable="@drawable/img05"         android:duration="200" /> </animation-list> 

第三步：布局文件和Activity

布局文件：布局文件中添加两个点击按钮和一个图片控件

<?xml version="1.0" encoding="utf-8"?> <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="https://schemas.android.com/apk/res/android"     xmlns:app="https://schemas.android.com/apk/res-auto"     xmlns:tools="https://schemas.android.com/tools"     android:layout_width="match_parent"     android:layout_height="match_parent"     tools:context=".MainActivity"> <Button         android:id="@+id/button"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_marginTop="100dp"         android:text="开始动画"         app:layout_constraintEnd_toEndOf="parent"         app:layout_constraintStart_toStartOf="parent"         app:layout_constraintTop_toTopOf="parent" /> <Button         android:id="@+id/button2"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_marginTop="16dp"         android:text="结束动画"         app:layout_constraintEnd_toEndOf="parent"         app:layout_constraintStart_toStartOf="parent"         app:layout_constraintTop_toBottomOf="@+id/button" /> <ImageView         android:id="@+id/image"         android:layout_width="200dp"         android:layout_height="200dp"         app:layout_constraintBottom_toBottomOf="parent"         app:layout_constraintLeft_toLeftOf="parent"         app:layout_constraintRight_toRightOf="parent"         android:background="@drawable/animation_flower"         app:layout_constraintTop_toBottomOf="@+id/button2" /> </androidx.constraintlayout.widget.ConstraintLayout> 

在Activity中添加启动&停止动画代码

public class MainActivity extends AppCompatActivity {     Button mButtonStart;     Button mButtonStop;     ImageView mImageViewShow;     AnimationDrawable mAnimationDrawable; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main);         mImageViewShow = findViewById(R.id.image); // 获取动画对象         mAnimationDrawable = (AnimationDrawable) mImageViewShow.getBackground();         mButtonStart = findViewById(R.id.button);         mButtonStart.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { //开始动画                 mAnimationDrawable.start(); } });          mButtonStop = findViewById(R.id.button2);         mButtonStop.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { //结束动画                 mAnimationDrawable.stop(); } }); } } 

方法2：用Java代码实现帧动画

Java代码实现帧动画跟xml很类似，只有Activity部分有点区别

public class MainActivity extends AppCompatActivity {     Button mButtonStart;     Button mButtonStop;     ImageView mImageViewShow;     AnimationDrawable mAnimationDrawable; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main);         mImageViewShow = findViewById(R.id.image); // 获取动画对象         mAnimationDrawable =new AnimationDrawable();         mAnimationDrawable.addFrame(getResources().getDrawable(R.drawable.img01),200);         mAnimationDrawable.addFrame(getResources().getDrawable(R.drawable.img02),200);         mAnimationDrawable.addFrame(getResources().getDrawable(R.drawable.img03),200);         mAnimationDrawable.addFrame(getResources().getDrawable(R.drawable.img04),200);         mAnimationDrawable.addFrame(getResources().getDrawable(R.drawable.img05),200);         mAnimationDrawable.addFrame(getResources().getDrawable(R.drawable.img06),200);         mAnimationDrawable.setOneShot(false);//设置循环播放         mImageViewShow.setBackground(mAnimationDrawable);          mButtonStart = findViewById(R.id.button);         mButtonStart.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { //开始动画                 mAnimationDrawable.start(); } });          mButtonStop = findViewById(R.id.button2);         mButtonStop.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { //结束动画                 mAnimationDrawable.stop(); } }); } }