Fragment 嵌套Fragment时，用getChildFragmentManager()

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/projectContent"
android:layout_width="match_parent"
android:layout_height="match_parent">

</FrameLayout>

@Override
public void onStart() {
    super.onStart();

    if (UserCenter.getIns().getUser().getHasProject() == 0) {
        showWeibaomingFragment(); //显示AFragment
    } else if(UserCenter.getIns().getUser().getHasProject() == 1) {
        showProjectFragment();    //显示BFragment
    }
}

private void showWeibaomingFragment() {
    FragmentManager fragmentManager = getChildFragmentManager();
    Fragment fragment = fragmentManager
            .findFragmentByTag(TAG_WEIBAOMING);
    if (null == fragment) {
        fragment = new WeiBMProjectFragment();
        fragmentManager
                .beginTransaction()
                .replace(R.id.projectContent, fragment,
                        TAG_WEIBAOMING).commit();
    }

}

private void showProjectFragment() {
    FragmentManager fragmentManager = getChildFragmentManager();
    Fragment fragment = fragmentManager
            .findFragmentByTag(TAG_PROJET);
    if (null == fragment) {
        fragment = new PersonalProjectMainFragment();
        fragmentManager
                .beginTransaction()
                .replace(R.id.projectContent, fragment,
                        TAG_PROJET).commit();
    }

}