ViewCompat.animate(view) floatEval.evaluate() argbEval.evaluate()

ViewCompat.animate(ivHead)
.translationX(60)
// .setInterpolator(new CycleInterpolator(4))//循环执行
// .setInterpolator(new OvershootInterpolator(4))//超过一点再回来
.setInterpolator(new BounceInterpolator())//动画插补器 实现反弹的效果
.setDuration(1000)
.start();

//执行动画
//1.获取main拖动的百分比:0-1f
float fraction = main.getLeft()*1f / maxLeft;

//fraction:0f - 1f
//main执行缩放动画
//scale: 1f - 0.8f
//算法: startVal + (endVal-startVal)*fraction
float scale = floatEval.evaluate(fraction,1f,0.8f);
main.setScaleY(scale);
main.setScaleX(scale);

//menu执行缩放
menu.setScaleX(floatEval.evaluate(fraction,0.3f,1f));
menu.setScaleY(floatEval.evaluate(fraction,0.3f,1f));
//menu执行平移
menu.setTranslationX(floatEval.evaluate(fraction,-menu.getMeasuredWidth()/2,0));

//立体3D效果
// main.setRotationY(floatEval.evaluate(fraction,0,90));
// menu.setRotationY(floatEval.evaluate(fraction,-90,0));

fraction是随着手势移动而变化的量

int color = (int) argbEval.evaluate(fraction,Color.BLACK,Color.TRANSPARENT);

getBackground().setColorFilter(color,PorterDuff.Mode.SRC_OVER);