title: Navigation drawer icon not showing
body: <p>I'm building Xamarin Android application and I want to implement right navigation drawer with drawer toogle in a custom action bar. Everything is working (drawer slides from right side,...) except one thing: the navigation drawer icon is not showing.</p>
  
  <p>So, this is my <code>Activity.axml</code>:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;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"&gt;
       &lt;android.support.v4.widget.DrawerLayout
             android:orientation="vertical"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
             android:background="#ffffff"
             android:id="@+id/drawerLayout"&gt;
  
             &lt;!-- Main Content --&gt;
             &lt;FrameLayout xmlns:tools="http://schemas.android.com/tools"
                 android:layout_width="match_parent"
                 android:layout_height="match_parent"&gt;
                 &lt;fragment
                      android:name="com.google.android.gms.maps.MapFragment"
                      android:layout_width="match_parent"
                      android:layout_height="match_parent"
                      android:scrollbars="vertical"
                      android:id="@+id/map" /&gt;
                       ...
             &lt;/FrameLayout&gt;
  
             &lt;!-- Right Navigation Drawer --&gt;
             &lt;LinearLayout
                 android:orientation="vertical"
                 android:layout_width="250dp"
                 android:layout_height="match_parent"
                 android:layout_gravity="right"
                 android:background="#f2f2f2"&gt;
                 ...
              &lt;/LinearLayout&gt;
       &lt;/android.support.v4.widget.DrawerLayout&gt;
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <p>And this is my <code>Activity.cs</code>:</p>
  
  <pre><code>using Android.Support.V4.App;
  using Android.Support.V4.Widget;
  ... 
  
  public class Activity : Activity
  {
      ...
      private DrawerLayout mDrawerLayout;
      private ActionBarDrawerToggle mDrawerToogle;
  
      protected override void OnCreate(Bundle savedInstanceState)
      {
          base.OnCreate(savedInstanceState);
  
          ActionBar.SetDisplayShowHomeEnabled(false);
          ActionBar.SetDisplayShowTitleEnabled(false);
          ActionBar.SetCustomView(Resource.Layout.CustomActionBar);
          ActionBar.SetDisplayShowCustomEnabled(true);
  
          SetContentView(Resource.Layout.Activity2);
  
          mDrawerLayout = FindViewById&lt;DrawerLayout&gt;(Resource.Id.drawerLayout);
          mDrawerToogle = new ActionBarDrawerToggle(this, mDrawerLayout, Resource.Drawable.ic_drawer,Resource.String.open_drawer_layout, Resource.String.close_drawer_layout);
  
          mDrawerLayout.SetDrawerListener(mDrawerToogle);
          ActionBar.SetDisplayHomeAsUpEnabled(true);
          ActionBar.SetHomeButtonEnabled(true);
  
          ...
      }
  
      protected override void OnPostCreate(Bundle savedInstanceState)
      {
          base.OnPostCreate(savedInstanceState);
          mDrawerToogle.SyncState();
      }
  
      public override void OnConfigurationChanged(Configuration newConfig)
      {
          base.OnConfigurationChanged(newConfig);
          mDrawerToogle.OnConfigurationChanged(newConfig);
      }
  
      public override bool OnOptionsItemSelected(IMenuItem item)
      {
          if (mDrawerToogle.OnOptionsItemSelected(item))
          {
              return true;
          }
  
          return base.OnOptionsItemSelected(item);
      }
      ...
  }
  </code></pre>
  
  <p>This is my <code>Themes.xml</code>:</p>
  
  <pre><code>&lt;resources&gt;
     &lt;style name="CustomActionBarTheme"
       parent="@android:style/Theme.Holo.Light.DarkActionBar"&gt;
         &lt;item name="android:actionBarStyle"&gt;@style/ActionBar&lt;/item&gt;
     &lt;/style&gt;
     &lt;style name="ActionBar"
       parent="@android:style/Widget.Holo.Light.ActionBar.Solid.Inverse"&gt;
         &lt;item name="android:height"&gt;75dp&lt;/item&gt;
         &lt;item name="android:background"&gt;#00000000&lt;/item&gt;
     &lt;/style&gt;
  &lt;/resources&gt;
  </code></pre>
  
  <p>Am I doing something wrong? Any help is appreciated.</p>
  
  <p><strong>UPDATE</strong></p>
  
  <p>My CustomActionBar has app icon and app title. Is this maybe interrupting navigation drawer icon?</p>