Can I change the Android startActivity() transition animation?

Question

Starting from API level 5 you can call overridePendingTransition immediately to specify an explicit transition animation:

startActivity();
overridePendingTransition(R.anim.hold, R.anim.fade_in);

or

finish();
overridePendingTransition(R.anim.hold, R.anim.fade_out);

See themes on android: http://developer.android.com/guide/topics/ui/themes.html.

Under themes.xml there should be android:windowAnimationStyle where you can see the declaration of the style in styles.xml.

Example implementation:

<style name="AppTheme" parent="...">

    ...

    <item name="android:windowAnimationStyle">@style/WindowAnimationStyle</item>

</style>

<style name="WindowAnimationStyle">
    <item name="android:windowEnterAnimation">@android:anim/fade_in</item>
    <item name="android:windowExitAnimation">@android:anim/fade_out</item>
</style>

In the same statement in which you execute finish(), execute your animation there too. Then, in the new activity, run another animation. See this code:

fadein.xml

<set xmlns:android="http://schemas.android.com/apk/res/android" 
     android:fillAfter="true">
     <alpha android:fromAlpha="1.0" 
            android:toAlpha="0.0"
            android:duration="500"/> //Time in milliseconds
</set>

In your finish-class

private void finishTask() {
    if("blabbla".equals("blablabla"){
        finish();
        runFadeInAnimation();
    }
}

private void runFadeInAnimation() {
    Animation a = AnimationUtils.loadAnimation(this, R.anim.fadein);
    a.reset();
    LinearLayout ll = (LinearLayout) findViewById(R.id.yourviewhere);
    ll.clearAnimation();
    ll.startAnimation(a);   
}

fadeout.xml

<set xmlns:android="http://schemas.android.com/apk/res/android"
           android:fillAfter="true">
  <alpha android:fromAlpha="0.0"
         android:toAlpha="1.0"
         android:duration="500"/>
</set>

In your new Activity-class you create a similiar method like the runFadeAnimation I wrote and then you run it in onCreate and don't forget to change the resources id to fadeout.

Use overridePendingTransition

startActivity();
overridePendingTransition(R.anim.fadein, R.anim.fadeout);

fadein.xml

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
    <alpha xmlns:android="http://schemas.android.com/apk/res/android"
        android:interpolator="@android:anim/accelerate_interpolator"
        android:fromAlpha="0.0" android:toAlpha="1.0" android:duration="500" />
</set>

fadeout.xml

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
    <alpha xmlns:android="http://schemas.android.com/apk/res/android"
        android:interpolator="@android:anim/anticipate_interpolator"
        android:fromAlpha="1.0" android:toAlpha="0.0" android:duration="500" />
</set>