sheishuoAPP/app/res/layout/chat_room_activity.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

  <fragment
        android:id="@+id/chat_rooms_fragment"
        android:name="com.sheishuo.app.chatroom.fragment.ChatRoomFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>


</LinearLayout>