写一个自定义view
package com.anguomob.guideline
import android.content.Context
import android.util.AttributeSet
import android.view.ViewAnimationUtils
import androidx.constraintlayout.widget.ConstraintHelper
import androidx.constraintlayout.widget.ConstraintLayout
import kotlin.math.hypot
class CircularReveal @JvmOverloads constructor(
context: Context, attrs: AttributeSet? = null
) :
ConstraintHelper(context, attrs) {
override fun updatePostLayout(container: ConstraintLayout?) {
super.updatePostLayout(container)
val views = getViews(container)
for (view in views) {
val a = hypot((view.height / 2).toDouble(), (view.width / 2).toDouble()).toFloat();
val anim = ViewAnimationUtils.createCircularReveal(
view, view.width / 2, view.height / 2, 0f, a
)
anim.duration = 3000;
anim.start()
}
}
}
使用
&l