完美解决Android App启动页有白屏闪过的问题

 <style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
    <!-- Customize your theme here. -->
    <item name="colorPrimary">@color/colorPrimary</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="colorAccent">@color/colorAccent</item>
  </style>

  <style name="AppTheme.Transparent">
    <item name="android:windowIsTranslucent">true</item>
    <item name="windowNoTitle">true</item>
  </style>

<activity android:name=".MainActivity"
      android:theme="@style/AppTheme.Transparent"
      >
      <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <action android:name="android.intent.action.VIEW"/>
        <category android:name="android.intent.category.LAUNCHER" />
      </intent-filter>
    </activity>

  <style name="SplashActivityThemes" parent="Theme.AppCompat.NoActionBar">
    <item name="android:windowBackground">@drawable/bg_splash</item>
    <item name="android:windowFullscreen">true</item>
  </style>

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >
  <item>
    <shape>
      <solid android:color="#FFFFFF"/>
    </shape>
  </item>
  <item
    android:bottom="50dp">
    <bitmap
      android:gravity="bottom|center_horizontal"
      android:src="@mipmap/icon_welcome"/>
  </item>
</layer-list>