無法在獨立視圖上啓動動畫製作工具

Question

我已經創建了在Kotlin中擴展PopupView的類，並嘗試將它與CircleReveal庫一起顯示爲動畫。這裏是我的類的功能

fun show(root: View) { 
    showAtLocation(root, Gravity.CENTER, 0, 0) 

    val cx = (mainView.left + mainView.right)/2 
    val cy = (mainView.top + mainView.bottom)/2 
    val dx = Math.max(cx, mainView.width - cx) 
    val dy = Math.max(cy, mainView.height - cy) 
    val finalRadius = Math.hypot(dx.toDouble(), dy.toDouble()).toFloat() 

    with (ViewAnimationUtils.createCircularReveal(mainView, cx, cy, 0f, finalRadius)) { 
     interpolator = AccelerateDecelerateInterpolator() 
     duration = 1500 
     start() 
    } 
} 

該代碼給我下面的錯誤

java.lang.IllegalStateException: Cannot start this animator on a detached view! 
                  at android.view.RenderNode.addAnimator(RenderNode.java:817) 
                  at android.view.RenderNodeAnimator.setTarget(RenderNodeAnimator.java:300) 
                  at android.view.RenderNodeAnimator.setTarget(RenderNodeAnimator.java:282) 
                  at android.animation.RevealAnimator.<init>(RevealAnimator.java:37) 
                  at android.view.ViewAnimationUtils.createCircularReveal(ViewAnimationUtils.java:53) 
                  at io.codetail.animation.ViewAnimationUtils.createCircularReveal(ViewAnimationUtils.java:74) 
                  at io.codetail.animation.ViewAnimationUtils.createCircularReveal(ViewAnimationUtils.java:39) 

類初始化

class MemberMenu(ctx: Context, val member: Member): PopupWindow(ctx), View.OnClickListener { 
val mainView: View 

init { 
    contentView = LayoutInflater.from(ctx).inflate(R.layout.member_menu_layout, null) 
    mainView = contentView.findViewById(R.id.member_menu_view) 
    val size = Helpers.dipToPixels(ctx, 240f) 
    width = size; height = size 
    setBackgroundDrawable(ColorDrawable()) 
    isOutsideTouchable = true 
    isTouchable = true 
} 
....... 

Answer 1

不知道，如果它是正確的解決方案，但我剛搬到該代碼OnAttachStateChangeListener

fun show(root: View) { 
     showAtLocation(root, Gravity.CENTER, 0, 0) 
     backgroundView.addOnAttachStateChangeListener(this) 
    } 

    override fun onViewAttachedToWindow(v: View?) { 
     if (v==null) return 

     with(ViewAnimationUtils.createCircularReveal(v, 500, 500, 0f, 500f)) { 
      interpolator = AccelerateDecelerateInterpolator() 
      duration = 2500 
      start() 
     } 
    } override fun onViewDetachedFromWindow(v: View?) {}