<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
 <!--背景色-->
 <item android:drawable="@color/white"/>
 <item>
  <!--图片-->
  <bitmap
   android:gravity="center"
   android:src="@mipmap/welcome_page"/>
 </item>
</layer-list>

<!-- Base application theme. -->
 <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
  <!-- Customize your theme here. -->
 </style>
 <style name="WelcomeThem" parent="AppTheme">
  <item name="android:windowBackground">@drawable/welcome</item>
 </style>

<!-- 欢迎页 -->
  <activity
   android:name=".ui.WelcomeActivity"
   android:windowSoftInputMode="adjustNothing" android:theme="@style/WelcomeThem">
   <intent-filter>
    <action android:name="android.intent.action.MAIN"/>
    <category android:name="android.intent.category.LAUNCHER"/>
   </intent-filter>
  </activity>

public class WelcomeActivity extends AppCompatActivity {
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  Intent intent = new Intent(this, MainActivity.class);
  startActivity(intent);
  finish();
 }
}