片段交易中的自定义动画无效

Question

MFragment fragment = new MFragment();
final FragmentTransaction fragmentTransaction = fragmentManager
                    .beginTransaction();
fragmentTransaction.setCustomAnimations(R.anim.slide_in_right,
        R.anim.slide_out_left, R.anim.slide_in_left,
        R.anim.slide_out_right);
fragmentTransaction.add(R.id.container, fragment,
        "frag1");
fragmentTransaction.commit();

new Handler().postDelayed(new Runnable() {
    @Override
    public void run() {
        MFragment fragment = new MFragment();
        final FragmentTransaction fragmentTransaction = fragmentManager
                .beginTransaction();
        fragmentTransaction.setCustomAnimations(R.anim.slide_in_right,
                R.anim.slide_out_left, R.anim.slide_in_left,
                R.anim.slide_out_right);
        fragmentTransaction.replace(R.id.container, fragment)
                .addToBackStack("frag2");
        fragmentTransaction.commit();
    }
}, 3000);

当我加载FragmentActivity并添加 frag1 时，添加了适当的动画，从右向左滑动。

但第二个片段 frag2 应该替换 frag1 ，会产生淡入/淡出动画，默认为。当我按下后退按钮时， frag2会以淡入淡出的动画弹出而不是从左向右滑出。

动画/ slide_in_right.xml

<set xmlns:android="http://schemas.android.com/apk/res/android"
    android:shareInterpolator="false" >

    <translate
        android:duration="200"
        android:fromXDelta="100%"
        android:fromYDelta="0%"
        android:toXDelta="0%"
        android:toYDelta="0%" />

</set>