圆形揭露动画

今天看官方的动画效果无意发现了这个动画,可能是之前没怎么关注吧使用也很简单,其实就是一个圆形缩小或者变大的动画.官方连接如下:
https://developer.android.com/training/animation/reveal-or-hide-view
中文地址如下:
https://developer.android.google.cn/training/animation/reveal-or-hide-view

具体使用如下

主要使用的是ViewAnimationUtils.createCircularReveal(view, cx, cy, initialRadius, 0F)这个方法,其中后面两个参数用来控制变大还是缩小

fun animator(view: View) {
        // Check if the runtime version is at least Lollipop
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            // get the center for the clipping circle
            val cx = view.width / 2
            val cy = view.height / 2
            // get the initial radius for the clipping circle
            val initialRadius = Math.hypot(cx.toDouble(), cy.toDouble()).toFloat()
            // create the animation (the final radius is zero)
            val anim = ViewAnimationUtils.createCircularReveal(view, cx, cy, initialRadius, 0F)

            // make the view invisible when the animation is done
            anim.addListener(object : AnimatorListenerAdapter() {

                override fun onAnimationEnd(animation: Animator) {
                    super.onAnimationEnd(animation)
                    view.visibility = View.INVISIBLE
                }
            })
            // start the animation
            anim.start()
        } else {
            // set the view to visible without a circular reveal animation below Lollipop
            view.visibility = View.INVISIBLE
        }
    }