单个Activity应用程序中的Splash-screen方法

Question

I am trying to decide on the best approach for creating an app splash-screen while taking into consideration Google's latest recommendations on choosing a single Activity app whenever possible.

See here:

"The new approach is to use one-activity structure whenever possible."

and here:

"Today we are introducing the Navigation component as a framework for structuring your in-app UI, with a focus on making a single-Activity app the preferred architecture."

Any good splash-screen approaches I have found have a dedicated Activity for the splash screen:

See here

and here

Has anyone else had any experience creating a splash screen in a single Activity app? Does the the single Activity recommendation include the splash-screen or is it a special case? Does anyone have any good examples or advice on this?

Cheers, Paul.

Answer 1

The approach I use is the following:

First define a drawable for the background:

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">

    <item
        android:drawable="@color/green"/>

    <item>
        <bitmap
            android:gravity="center"
            android:src="@mipmap/ic_launcher"/>
    </item>

</layer-list>

2. Define a new style to use in the splashScreen:

<style name="SplashTheme" parent="Theme.AppCompat.NoActionBar">
    <item name="android:windowBackground">@drawable/background_splash</item>
</style>

3. Make your activity implement use the splash theme:

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

4. In on create, before the super invocation and before the set content view set the default app theme:

override fun onCreate(savedInstanceState: Bundle) {
    setTheme(android.R.style.AppTheme)
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main);
}

This approach is the one I've been using even with multiple Activities, since it follows the guidelines laid down by google: itshows the splash right away and doesn't stay longer than needed.

Answer 2

If you are using ConstraintLayout in your layouts, you can use the Group class of Android to group multiple views. Please refer to the following link for more information.

https://developer.android.com/reference/android/support/constraint/Group

This class controls the visibility of a set of referenced widgets. Widgets are referenced by being added to a comma separated list of ids, eg:

 <android.support.constraint.Group
          android:id="@+id/group"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:visibility="visible"
          app:constraint_referenced_ids="button4,button9" />

FYI - Multiple groups can reference the same widgets -- in that case, the XML declaration order will define the final visibility state (the group declared last will have the last word).

Hope this helps you resolve the issue.