About white screen issues when the app just started

Problem Description: Click the launch icon, when you start the app, the app will have a short blank view, and then it will show the first activity launched by the app.

What caused this phenomenon. Step: Start-up-blank view--> show the app's first activity

Because the windowbackground and other backgrounds are set to white when theme set style in Androidmanifest.xml,

Customizing a Style

If the start page is a picture:
<style name= "Start_theme" parent= "@android: Style/theme.notitlebar" >
    <item name= " Android:windowbackground "> @drawable/Start Page picture name </item>
    <item name=" Android:windownotitle ">true </item>
  </style>

Another way is to set windowbackground to transparent, this has a disadvantage is to click on the start icon, give a sense of the start delay

<style name= "Start_theme" parent= "@android: Style/theme.notitlebar ">

        <item name= "android:windowistranslucent" >true</item>
        <item name= "Android:windownotitle" > True</item>
 </style>