Android - Custom Animation on fragment transaction not running

As suggested above, separate statements will definitely work. But the trick here is to setCustomAnimation before setting transaction type viz.add, replace, etc. else it doesn't. So, applying the same logic, method chaining also works. eg.

getSupportFragmentManager()
        .beginTransaction()
        .setCustomAnimations(R.anim.a_slide_up,
                             R.anim.a_slide_down,
                             R.anim.a_slide_up,
                             R.anim.a_slide_down)
        .add(R.id.root_layout, 
             MyFrag.newInstance())
        .addToBackStack("MyFrag")
        .commit();

Putting it here, so that someone who prefers method chaining finds it helpful. Cheers!

The manager was stacking my transaction before I set the animation, so it stacks the transaction without animations (sad but true), and that occurs even if I commit the transaction after the setCustomAnimations().

The solution is to set the animations first:

FragmentTransaction transaction = manager.beginTransaction();       
transaction.setCustomAnimations(R.anim.slide_in_left, R.anim.slide_out_right);
transaction.replace(R.id.content, myFragment);
transaction.commit();

Leaving this here as it's the most popular question. I had the same problem with fragment transaction not animating. The culprit was having the attribute android:animateLayoutChanges set to true in the containing layout.

I hope it helps someone save some time looking for a solution as it can be hard to notice when having nested layouts in different files.