Android - Launch Fragment from another Fragment

Question

I have been stuck in this issue for almost 10 days, I have searched all over the Internet for a solution and I have tried them all but no one is working with me. Fragment1.cs

public override View OnCreateView(LayoutInflater inflater, ViewGroup 
 container, Bundle savedInstanceState)
  {
base.OnCreate(savedInstanceState);
View view = inflater.Inflate(Resource.Layout.my_layout, container, false);
add.Click += delegate
    {
        Fragment2 fragment2 = new Fragment2();
        FragmentTransaction ft = FragmentManager.BeginTransaction();
        ft.Replace(Resource.Id.content_frame, fragment2);
        ft.Commit();
     };
return view;
}

Fragment2.cs

public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
    base.OnCreate(savedInstanceState);
    View view = inflater.Inflate(Resource.Layout.fragment_lay, container, false);

    TextView txt = view.FindViewById<TextView>(Resource.Id.textView1);
    Button btn = view.FindViewById<Button>(Resource.Id.button1);
    listView = view.FindViewById<ListView>(Resource.Id.listView1);
    Toast.MakeText(Activity, "Fragment2 started", ToastLength.Short).Show();
    return view;
   }

my_layout

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/content_frame">
<TextView
    android:text="Text"
    android:layout_width="match_parent"
    android:layout_height="70dp"
    android:id="@+id/total"
    android:textAlignment="center"
    android:textSize="30dp" />
<TextView
    android:text="Text"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/textchangevalue"
    android:textSize="33dip"
    android:textStyle="bold" />
<Button
    android:text="UPDATE"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:id="@+id/updatebtn" />
<Button
    android:text="ADD"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:id="@+id/addbtn" />
<ListView
    android:minWidth="25px"
    android:minHeight="25px"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/portfoliolist"
    android:clickable="true" />

I have tried to change the layout of the Fragment1 by putting instead of <LinearLayout> a <FrameLayout> but also didn't worked. I have put a toast message in the Fragment2 and when I click the addbutton in the Fragment1, the toast message (which is in the fragment2) is showing which means that the fragment2 is starting fine but it's layout is not showing on the screen. Please help me to find a solution.