//1、繼承RelativeLayoutpublic class ChristmasView extends RelativeLayout implements View.OnClickListener { private Context context; //2、準備幾張點贊圖片 private int[] christmas_drawable = {R.drawable.christmas01, R.drawable.christmas02, R.drawable.christmas03  , R.drawable.christmas04, R.drawable.christmas05, R.drawable.christmas06}; //隨機數種子 private Random random = new Random(); //View的寬高 private int width, height; //圖片的寬高 private int drawableWidth, drawableHeight; public ChristmasView(Context context) { this(context, null); } public ChristmasView(Context context, AttributeSet attrs) { this(context, attrs, 0); } public ChristmasView(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); this.context = context; //3、設置點擊事件 setOnClickListener(this); //4、獲取點贊圖片的寬高 Drawable drawable = ContextCompat.getDrawable(context, R.drawable.christmas01); drawableWidth = drawable.getIntrinsicWidth(); drawableHeight = drawable.getIntrinsicHeight(); }}@Overridepublic void onClick(View v) { //5、點擊增加點贊圖片 addChristmas(context);}

private void addChristmas(Context context) { /** * 1、點擊一次增加一張圖片在底部 */ final ImageView imageView = new ImageView(context); imageView.setBackgroundResource(christmas_drawable[random.nextInt(christmas_drawable.length - 1)]); RelativeLayout.LayoutParams params = new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,  ViewGroup.LayoutParams.WRAP_CONTENT); params.addRule(ALIGN_PARENT_BOTTOM); params.addRule(CENTER_HORIZONTAL); imageView.setLayoutParams(params); addView(imageView); //2、開始執行點贊效果 AnimatorSet animatorSet = getAnimatorSet(imageView); animatorSet.addListener(new AnimatorListenerAdapter() { @Override public void onAnimationEnd(Animator animation) {  //3、動畫執行后移除View  removeView(imageView); } }); animatorSet.start();}

private AnimatorSet getAnimatorSet(ImageView imageView) { AnimatorSet enter = new AnimatorSet(); //1、縮放動畫 AnimatorSet scaleAnimator = new AnimatorSet(); ObjectAnimator alpha = ObjectAnimator.ofFloat(imageView, "alpha", 0.3f, 1f); ObjectAnimator scaleX = ObjectAnimator.ofFloat(imageView, "scaleX", 0.3f, 1f); ObjectAnimator scaleY = ObjectAnimator.ofFloat(imageView, "scaleY", 0.3f, 1f); scaleAnimator.setDuration(300); scaleAnimator.playTogether(alpha, scaleX, scaleY); //2、貝塞爾動畫 ValueAnimator bezierAnimator = getBezierAnimator(imageView); //3、兩個動畫按順序播放 enter.playSequentially(scaleAnimator, bezierAnimator); return enter;}

/** * 貝塞爾曲線估值器：計算動畫的執行軌跡 * * @params 傳入貝塞爾曲線需要的四個點 * @return 通過計算返回貝塞爾曲線的坐標 */public class BezierEvaluator implements TypeEvaluator<PointF> { private PointF point1; private PointF point2; public BezierEvaluator(PointF point1, PointF point2) { this.point1 = point1; this.point2 = point2; } @Override public PointF evaluate(float t, PointF point0, PointF point3) { PointF point = new PointF(); //t 取值為 [0,1] /**  * 三階貝塞爾公式  *  * B(t)=(1 - t)^3 P0  * + 3 t (1 - t)^2 P1  * + 3 t^2 (1 - t) P2  * + t^3 P3  */ point.x = point0.x * (1 - t) * (1 - t) * (1 - t)  + 3 * point1.x * t * (1 - t) * (1 - t)  + 3 * point2.x * t * t * (1 - t)  + point3.x * t * t * t; /**  * 三階貝塞爾公式  *  * B(t)=(1 - t)^3 P0  * + 3 t (1 - t)^2 P1  * + 3 t^2 (1 - t) P2  * + t^3 P3  */ point.y = point0.y * (1 - t) * (1 - t) * (1 - t)  + 3 * point1.y * t * (1 - t) * (1 - t)  + 3 * point2.y * t * t * (1 - t)  + point3.y * t * t * t; return point; }}

/** * 貝塞爾動畫 * * @return */private ValueAnimator getBezierAnimator(final ImageView imageView) { //1、構建貝塞爾曲線的四個點 PointF point0 = new PointF((width - drawableWidth) / 2, height - drawableHeight); PointF point1 = new PointF(random.nextInt(width), random.nextInt(height / 2)); PointF point2 = new PointF(random.nextInt(width), random.nextInt(height / 2) + height / 2); PointF point3 = new PointF(random.nextInt(width - drawableWidth), 0); //2、創建貝塞爾屬性動畫 BezierEvaluator evaluator = new BezierEvaluator(point1, point2); final ValueAnimator valueAnimator = ObjectAnimator.ofObject(evaluator, point0, point3); valueAnimator.setInterpolator(new LinearInterpolator()); valueAnimator.setDuration(3000); //3、監聽貝塞爾曲線估值器返回值 valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() { @Override public void onAnimationUpdate(ValueAnimator animation) {  //4、獲取BezierEvaluator中evaluate()返回的運行軌跡坐標點，設置點贊圖片路線  PointF pointF = (PointF) animation.getAnimatedValue();  imageView.setX(pointF.x);  imageView.setY(pointF.y);  //6、獲取BezierEvaluator中evaluate()返回的參數t，設置消失動畫  float t = animation.getAnimatedFraction();  imageView.setAlpha(1 - t + 0.2f); } }); return valueAnimator;}

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <com.handsome.boke2.CustomView.ChristmasView android:layout_width="100dp" android:layout_height="200dp" android:layout_alignParentBottom="true" android:layout_alignParentRight="true" /></RelativeLayout>