揭露动画（Reveal Effect）实现时的注意事项（附上bug-logcat）

Debug完成图：

昨天晚上开始学一下这个揭露动画，准备用在项目中做一个转场，啃完了API之后开始写个小demo，距离跑成功一步之遥的当儿，出了个bug，就怎么点击按钮都没用。

首先上bug图：

bug：怎么点击按钮都没用，每点击一次都会出现下面的报错（2040）：

11-07 19:20:49.665 2454-2454/? I/Finsky: [1] com.google.android.finsky.services.j.a(149): Installation state replication succeeded. 11-07 19:20:49.711 7448-7448/? E/hei: 2040 11-07 19:20:49.718 1350-1371/? W/audio_hw_generic: Not supplying enough data to HAL, expected position 5613338 , only wrote 5613120 11-07 19:20:50.376 7448-7448/? E/hei: 2040 11-07 19:20:50.992 7448-7448/? E/hei: 2040 11-07 19:20:51.591 7448-7448/? E/hei: 2040 11-07 19:20:54.790 1350-1372/? W/audio_hw_generic: Not supplying enough data to HAL, expected position 6098164 , only wrote 5856480 11-07 19:20:58.322 7448-7448/? E/hei: 2040 11-07 19:20:58.328 1350-1371/? W/audio_hw_generic: Not supplying enough data to HAL, expected position 5856667 , only wrote 5856480 11-07 19:21:01.540 1350-1372/? W/audio_hw_generic: Not supplying enough data to HAL, expected position 6162708 , only wrote 6010560 

activity.java全文：

package com.lwp.justtest; import android.animation.Animator; import android.animation.AnimatorListenerAdapter; import android.support.design.widget.FloatingActionButton; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.util.Log; import android.view.View; import android.view.ViewAnimationUtils; public class MainActivity extends AppCompatActivity implements View.OnClickListener { boolean flag = false; FloatingActionButton fab; private View mPuppet; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mPuppet = findViewById(R.id.view_puppet); fab = (FloatingActionButton)findViewById(R.id.fab); fab.setOnClickListener(this); } @Override public void onClick(View v) { doRevealAnimation(); } private void doRevealAnimation() { int[] vLocation = new int[2]; fab.getLocationInWindow(vLocation); int centerX = vLocation[0] + fab.getMeasuredWidth() / 2; int centerY = vLocation[1] + fab.getMeasuredHeight() / 2; int height = mPuppet.getHeight(); int width = mPuppet.getWidth(); int maxRradius = (int) Math.hypot(height, width); Log.e("hei", maxRradius + ""); if (flag) { Animator animator = ViewAnimationUtils.createCircularReveal(mPuppet, centerX, centerY, maxRradius, 0); animator.setDuration(1000); animator.addListener(new AnimatorListenerAdapter() { @Override public void onAnimationEnd(Animator animation) { super.onAnimationEnd(animation); mPuppet.setVisibility(View.GONE); } }); animator.start(); flag = false; } else { Animator animator = ViewAnimationUtils.createCircularReveal(mPuppet, centerX, centerY, 0, maxRradius); animator.setDuration(1000); animator.addListener(new Animator.AnimatorListener() { @Override public void onAnimationStart(Animator animation) { mPuppet.setVisibility(View.VISIBLE); } @Override public void onAnimationEnd(Animator animation) { } @Override public void onAnimationCancel(Animator animation) { } @Override public void onAnimationRepeat(Animator animation) { } }); animator.start(); flag = true; } } } 

layout.xml全文：

<?xml version="1.0" encoding="utf-8"?> <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context="com.lwp.justtest.MainActivity"> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:layout_gravity="center" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <View android:id="@+id/view_puppet" android:layout_width="match_parent" android:layout_height="match_parent"/> <android.support.design.widget.FloatingActionButton android:id="@+id/fab" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="bottom|end" android:layout_margin="16dp" android:backgroundTint="@color/colorPrimary" android:src="@drawable/map" app:pressedTranslationZ="10dp" /> </FrameLayout> 

观众朋友们，这个看出毛病了吗。

我想了一下，额，会不会我的View没有设置颜色啊。。好的试了一下，果然是，可以说是很鬼畜了。。

layout.xml里边的View控件改成下面这样子，再次运行程序就成了（发现2040还是会报错，但是动画算是完美跑出来了，所以小伙伴们这里记得设置android:background以及android:visibility噢）：

 <View android:id="@+id/view_puppet" android:background="@color/colorPrimaryDark" android:layout_width="match_parent" android:layout_height="match_parent" android:visibility="gone"/> 

效果图如下：