揭露動畫實現時的注意事項（附上bug-logcat）

摘要： 昨天晚上開始學一下這個揭露動畫，準備用在專案中做一個轉場，啃完了API之後開始寫個小demo，距離跑成功一步之遙的當兒，出了個bug，就怎麼點選按鈕都沒用。 首先上bug圖： bug：怎麼點選按鈕都沒用，每點選一次都會出現下面的報錯（2040）： 11-07...

昨天晚上開始學一下這個揭露動畫，準備用在專案中做一個轉場，啃完了API之後開始寫個小demo，距離跑成功一步之遙的當兒，出了個bug，就怎麼點選按鈕都沒用。

首先上bug圖：

bug：怎麼點選按鈕都沒用，每點選一次都會出現下面的報錯（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>

觀眾朋友們，這個看出毛病了嗎。

我想了一下，額，會不會我的View沒有設定顏色啊。。好的試了一下，果然是，可以說是很鬼畜了。。

layout.xml裡邊的View控制元件改成下面這樣子，再次執行程式就成了（發現2040還是會報錯，但是動畫算是完美跑出來了，所以小夥伴們這裡記得設定 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"/>

效果圖如下：