替换子片段

我是Android开发新手。我使用Xamarin Android开发一个Android应用程序。我有问题时，在替换碎片碎片，在一个模板应用程序上工作，我想用FragmentB代替FragmentA。在Main Activity中，content_frame被FragmentA取代。

这是我目前拥有的代码

主要。axml

<?xml version="1.0" encoding="utf-8"?>
        <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:orientation="vertical">
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:textAppearance="?android:attr/textAppearanceLarge"
                android:text="MAIN ACTIVITY" />
            <FrameLayout
                android:id="@+id/parent_fragment"
                android:layout_width="fill_parent"
                android:layout_height="200dip" />
</LinearLayout>

MainActivity.cs

[Activity(Label = "NestedFrags", MainLauncher = true, Icon = "@drawable/icon")]
    public class MainActivity : Activity
    {
        int count = 1;
        protected override void OnCreate(Bundle bundle)
        {
            base.OnCreate(bundle);
            // Set our view from the "main" layout resource
            SetContentView(Resource.Layout.Main);
            Fragment fragA = new FragmentA();
            FragmentManager.BeginTransaction().Replace(Resource.Id.parent_fragment, fragA).Commit();
        }
    }

FragmentA.axml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:minWidth="25px"
    android:minHeight="25px">
    <TextView
        android:text="Parent Fragment"
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/textView1" />
    <FrameLayout
        android:id="@+id/child_fragment"
        android:layout_width="fill_parent"
        android:layout_height="200dip" />
</LinearLayout>

FragmentA.cs

public class FragmentA : Fragment
    {
        public override void OnCreate(Bundle savedInstanceState)
        {
            Fragment fragmentB = new FragmentB();
            FragmentTransaction transaction = ChildFragmentManager.BeginTransaction();
            transaction.Add(Resource.Id.child_fragment, fragmentB).Commit();
            base.OnCreate(savedInstanceState);
        }
        public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
        {
            View view = inflater.Inflate(Resource.Layout.fraga, container, false);
            return view;
        }
    }

FragmentB.axml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:minWidth="25px"
    android:minHeight="25px">
    <TextView
        android:text="Child Fragment of A"
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/textView2" />
</LinearLayout>

FragmentB.cs

 public class FragmentB : Fragment
    {
        public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
        {
            View view = inflater.Inflate(Resource.Layout.fragb, container, false);
            return view;
        }
    }

到目前为止，我还可以一个一个地替换碎片。但我试图用fragmentB完全取代fragmentA。有人能帮帮我吗?我不介意如果有人可以在Java回答，因为我只是需要一些工作，我会根据Java解决方案改变我的代码。

提前感谢所有或任何帮助。

        Fragment fragB = new FragmentB();
        FragmentManager.BeginTransaction().Replace(Resource.Id.parent_fragment, fragB).Commit();