android - Navigation drawer doesn't show icon in actionbar

Question

I have added navigation drawer to an activity which contains PagerSlidingStrip.I can see the navigation drawer when I slide from left to right of screen but I can't see navigation drawer icon in action bar. Below is my code-

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <FrameLayout
        android:id="@+id/content_frame_main"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
    <com.astuetz.PagerSlidingTabStrip
        android:id="@+id/tabs"
        android:layout_width="match_parent"
        android:layout_height="48dip"
        android:background="#8E58D4"
        app:pstsIndicatorColor="#5B349E"

        app:pstsDividerColor="#8E58D4"
        app:pstsTabSwitch="true"
      />
    <android.support.v4.view.ViewPager
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:id="@+id/viewPager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_below="@+id/tabs"
        android:layout_alignParentBottom="true" />


</RelativeLayout>

    <ListView android:id="@+id/left_drawer"
        android:layout_width="240dp"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        android:choiceMode="singleChoice"
        android:divider="@android:color/transparent"
        android:dividerHeight="0dp"
        android:background="#111"/>
    </android.support.v4.widget.DrawerLayout>

Answer 1

add this

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    super.onCreateOptionsMenu(menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {

    return super.onOptionsItemSelected(item);
}