Main Activirty untuk container

main_activity.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="id.kalviansofian.belajarfragment.MainActivity">


    <LinearLayout
        android:id="@+id/action_container"
        android:layout_width="match_parent"
        android:layout_height="300dp"
        android:orientation="vertical" />


    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/action_container"
        android:orientation="vertical"
        android:padding="10dp">

        <Button
            android:id="@+id/addFragment"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Add Fragment" />

        <Button
            android:id="@+id/replaceFragment"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_below="@+id/action_container"
            android:text="Replace Fragment" />

        <Button
            android:id="@+id/removeFragment"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_below="@+id/action_container"
            android:text="Remove Fragment" />
    </LinearLayout>
</RelativeLayout>