Android贝塞尔曲线实现直播点赞效果

//1、继承RelativeLayoutpublic class ChristmasView extends RelativeLayout implements View.OnClickListener { private Context context; //2、准备几张点赞图片 private int[] christmas_drawable = {R.drawable.christmas01, R.drawable.christmas02, R.drawable.christmas03  , R.drawable.christmas04, R.drawable.christmas05, R.drawable.christmas06}; //随机数种子 private Random random = new Random(); //View的宽高 private int width, height; //图片的宽高 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、设置点击事件 setOnClickListener(this); //4、获取点赞图片的宽高 Drawable drawable = ContextCompat.getDrawable(context, R.drawable.christmas01); drawableWidth = drawable.getIntrinsicWidth(); drawableHeight = drawable.getIntrinsicHeight(); }}@Overridepublic void onClick(View v) { //5、点击增加点赞图片 addChristmas(context);}

private void addChristmas(Context context) { /** * 1、点击一次增加一张图片在底部 */ 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、开始执行点赞效果 AnimatorSet animatorSet = getAnimatorSet(imageView); animatorSet.addListener(new AnimatorListenerAdapter() { @Override public void onAnimationEnd(Animator animation) {  //3、动画执行后移除View  removeView(imageView); } }); animatorSet.start();}

private AnimatorSet getAnimatorSet(ImageView imageView) { AnimatorSet enter = new AnimatorSet(); //1、缩放动画 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、贝塞尔动画 ValueAnimator bezierAnimator = getBezierAnimator(imageView); //3、两个动画按顺序播放 enter.playSequentially(scaleAnimator, bezierAnimator); return enter;}

/** * 贝塞尔曲线估值器：计算动画的执行轨迹 * * @params 传入贝塞尔曲线需要的四个点 * @return 通过计算返回贝塞尔曲线的坐标 */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 取值为 [0,1] /**  * 三阶贝塞尔公式  *  * 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; /**  * 三阶贝塞尔公式  *  * 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; }}

/** * 贝塞尔动画 * * @return */private ValueAnimator getBezierAnimator(final ImageView imageView) { //1、构建贝塞尔曲线的四个点 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、创建贝塞尔属性动画 BezierEvaluator evaluator = new BezierEvaluator(point1, point2); final ValueAnimator valueAnimator = ObjectAnimator.ofObject(evaluator, point0, point3); valueAnimator.setInterpolator(new LinearInterpolator()); valueAnimator.setDuration(3000); //3、监听贝塞尔曲线估值器返回值 valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() { @Override public void onAnimationUpdate(ValueAnimator animation) {  //4、获取BezierEvaluator中evaluate()返回的运行轨迹坐标点，设置点赞图片路线  PointF pointF = (PointF) animation.getAnimatedValue();  imageView.setX(pointF.x);  imageView.setY(pointF.y);  //6、获取BezierEvaluator中evaluate()返回的参数t，设置消失动画  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>