title: Xamarin.Android : CS0103 The name 'SetSupportActionBar' does not exist in the current context
body: <p>CS0103 The name 'SetSupportActionBar' does not exist in the current context</p>
  
  <p>Am clean and build many of time but this error is occur and i will change my manifest xml theme also but there is an error how to can solve this issue</p>
  
  <p>my android target platform api 27 and minimum 18</p>
  
  <p>my mainactivity.cs only the error is occur how to solve this issue </p>
  
  <p>i will find some answers from stackoverflow but it not solving my issue</p>
  
  <p>MainActivity.cs</p>
  
  <pre><code>using System;
  using Android.App;
  using Android.Content;
  using Android.Runtime;
  using Android.Views;
  using Android.Widget;
  using Android.OS;
  using Android.Support.V7.App;
  using Android.Support.V4.Widget;
  using V7Toolbar = Android.Support.V7.Widget.Toolbar;
  using Android.Support.Design.Widget;
  
  namespace NavigationDrawerLayout
  {
      [Activity(Label = "NavigationDrawerLayout", Theme = "@style/Theme.DesignDemo", MainLauncher = true, Icon = "@drawable/icon")]
      public class MainActivity : AppCompatActivity
      {
  
          DrawerLayout drawerLayout;
          NavigationView navigationView;
          protected override void OnCreate(Bundle bundle)
          {
              base.OnCreate(bundle);
  
              // Set our view from the "main" layout resource
              SetContentView(Resource.Layout.Main);
  
              drawerLayout = FindViewById&lt;DrawerLayout&gt;(Resource.Id.drawer_layout);
  
  
              // Create ActionBarDrawerToggle button and add it to the toolbar
              var toolbar = FindViewById&lt;V7Toolbar&gt;(Resource.Id.toolbar);
              SetSupportActionBar(toolbar);
  
  
              var drawerToggle = new ActionBarDrawerToggle(this, drawerLayout, toolbar, Resource.String.drawer_open, Resource.String.drawer_close);
              drawerLayout.SetDrawerListener(drawerToggle);
              drawerToggle.SyncState();
  
              navigationView = FindViewById&lt;NavigationView&gt;(Resource.Id.nav_view);
              setupDrawerContent(navigationView);
          }
          void setupDrawerContent(NavigationView navigationView)
          {
              navigationView.NavigationItemSelected += (sender, e) =&gt; {
                  e.MenuItem.SetChecked(true);
                  drawerLayout.CloseDrawers();
              };
          }
  
          public override bool OnCreateOptionsMenu(IMenu menu)
          {
  
              navigationView.InflateMenu(Resource.Menu.nav_menu);
              return true;
  
          }
  
          }
  }
  </code></pre>
  
  <p>toolbar.axml </p>
  
  <pre><code> &lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  android:id="@+id/main_content"
  android:layout_width="match_parent"
  android:layout_height="match_parent"&gt;
  &lt;android.support.design.widget.AppBarLayout
  android:id="@+id/appbar"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"&gt;
  &lt;android.support.v7.widget.Toolbar
  android:id="@+id/toolbar"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:elevation="4dp"
  android:background="?attr/colorPrimary" /&gt;
  &lt;/android.support.design.widget.AppBarLayout&gt;
  &lt;/android.support.design.widget.CoordinatorLayout&gt;
  `
  </code></pre>
  
  <p>styles.xml</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8" ?&gt;
  &lt;resources&gt;
    &lt;style name="Theme.DesignDemo" parent="Base.Theme.DesignDemo"&gt;&lt;/style&gt;
    &lt;style name="Base.Theme.DesignDemo" parent="Theme.AppCompat.Light.NoActionBar"&gt;
      &lt;item name="colorPrimary"&gt;#2196F3&lt;/item&gt;
      &lt;item name="colorPrimaryDark"&gt;#1976D2&lt;/item&gt;
      &lt;item name="android:windowBackground"&gt;@color/window_background&lt;/item&gt;
    &lt;/style&gt;
  &lt;/resources&gt;
  </code></pre>