private void ShowFragment(Android.App.Fragment fragment)
    {
        var trans = FragmentManager.BeginTransaction();

        // this line below set an animation
        trans.SetCustomAnimations(Resource.Animation.frag_slide_in, Resource.Animation.frag_slide_out);

        trans.Hide(mCurrentFragment);
        trans.Show(fragment);
        trans.AddToBackStack(null);
        trans.Commit();
        mStackFragment.Push(mCurrentFragment);
        mCurrentFragment = fragment;
    }

<?xml version="1.0" encoding="UTF-8" ?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
     android:interpolator="@android:interpolator/anticipate">

    <translate
        android:fromXDelta="0"
        android:toXDelta="100%"
        android:duration="650"/>

    <alpha
        android:fromAlpha="1.0"
        android:toAlpha="0.5"
        android:duration="650"/>
</set>