title: Do not request Window.FEATURE_SUPPORT_ACTION_BAR and set windowActionBar to false in your theme to use a Toolbar instead
body: <p>I'm trying to set up a toolbar with a burger menu, this is my code,and
  the error is:</p>
  
  <blockquote>
    <p>This Activity already has an action bar supplied by the window decor.
    Do not request <code>Window.FEATURE_SUPPORT_ACTION_BAR</code> and set
    windowActionBar to false in your theme to use a Toolbar instead.</p>
  </blockquote>
  
  <p>The problem is that I don't know where I am getting the error from, and
  also the fact that I tried everything.</p>
  
  <p><strong>MainActivity.java</strong></p>
  
  <pre><code>    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
      setSupportActionBar(toolbar);
      txResult = (TextView) findViewById(R.id.txResult);
      toolbar = (Toolbar) findViewById(R.id.toolbar);
      setSupportActionBar(toolbar);
      mDrawer = (DrawerLayout) findViewById(R.id.drawer_layout);}
  
  // Set a Toolbar to replace the ActionBar.
  
  
  // Find our drawer view
  
  
  
  private void setupDrawerContent(NavigationView navigationView) {
      navigationView.setNavigationItemSelectedListener(
              new NavigationView.OnNavigationItemSelectedListener() {
                  @Override
                  public boolean onNavigationItemSelected(MenuItem menuItem) {
                      selectDrawerItem(menuItem);
                      return true;
                  }
              });
  }
  
  public void selectDrawerItem(MenuItem menuItem) {
      // Create a new fragment and specify the planet to show based on
      // position
      Fragment fragment = null;
  
      Class fragmentClass;
      switch(menuItem.getItemId()) {
          case R.id.nav_first_fragment:
              fragmentClass = MainActivity.class;
              break;
          case R.id.nav_second_fragment:
              fragmentClass = SecondActivity.class;
              break;
          case R.id.nav_third_fragment:
              fragmentClass = ThirdActivity.class;
              break;
          default:
              fragmentClass = MainActivity.class;
      }
  
      try {
          fragment = (Fragment) fragmentClass.newInstance();
      } catch (Exception e) {
          e.printStackTrace();
      }
  
      // Insert the fragment by replacing any existing fragment
      FragmentManager fragmentManager = getSupportFragmentManager();
      fragmentManager.beginTransaction().replace(R.id.flContent, fragment).commit();
  
      // Highlight the selected item, update the title, and close the drawer
      menuItem.setChecked(true);
      setTitle(menuItem.getTitle());
      mDrawer.closeDrawers();
  }
  
  @Override
  public boolean onOptionsItemSelected(MenuItem item) {
      // The action bar home/up action should open or close the drawer.
      switch (item.getItemId()) {
          case android.R.id.home:
              mDrawer.openDrawer(GravityCompat.START);
              return true;
      }
  
      return super.onOptionsItemSelected(item);
  }
  </code></pre>
  
  <p><strong>MainActivity.xml</strong></p>
  
  <pre><code>&lt;!-- This DrawerLayout has two children at the root  --&gt;
   &lt;android.support.v4.widget.DrawerLayout
       xmlns:android="http://schemas.android.com/apk/res/android"
       xmlns:app="http://schemas.android.com/apk/res-auto"
       android:id="@+id/drawer_layout"
       android:layout_width="match_parent"
       android:layout_height="match_parent"&gt;
  
       &lt;!-- This LinearLayout represents the contents of the screen  --&gt;
       &lt;LinearLayout
           android:layout_width="match_parent"
           android:layout_height="match_parent"
           android:orientation="vertical"&gt;
  
           &lt;include
               layout="@layout/toolbar"
               android:layout_width="match_parent"
               android:layout_height="wrap_content" /&gt;
  
           &lt;View
               android:layout_width="match_parent"
               android:layout_height="1dp"
               android:layout_marginTop="10dp"
               android:layout_marginBottom="10dp"
               android:background="#ddd"
              android:visibility="invisible" /&gt;
  
           &lt;View
               android:layout_width="match_parent"
               android:layout_height="1dp"
               android:layout_marginTop="10dp"
               android:layout_marginBottom="10dp"
               android:background="#ddd"
               android:visibility="invisible" /&gt;
  
           &lt;TextView
               android:id="@+id/txResult"
               android:layout_width="match_parent"
               android:layout_height="wrap_content"
               android:text="Rezultat:"
               android:textSize="20sp"
               android:visibility="invisible" /&gt;
  
           &lt;Button
               android:layout_width="207dp"
               android:layout_height="wrap_content"
               android:text="Scan"
               android:radius="3dp"
               android:shape="oval"
               android:width="5px"
               android:color="#1a1a1a"
               android:onClick="callZXing"
               android:id="@+id/Button"
               android:layout_centerHorizontal="true"
               android:background="#F39C12"
               android:textColor="#ffffff"
               android:layout_above="@+id/button2"
               android:singleLine="false"
               android:soundEffectsEnabled="false" /&gt;
  
           &lt;Button
               style="@style/CaptureTheme"
               android:layout_width="112dp"
               android:layout_height="68dp"
               android:text="No"
               android:id="@+id/button1"
               android:layout_weight="0.10"
               android:layout_gravity="center_horizontal"
               android:onClick="sendFirst"
               android:visibility="visible"
               android:layout_alignParentBottom="true"
               android:layout_centerHorizontal="true"
               android:layout_marginBottom="60dp" /&gt;
  
           &lt;Button
               style="@style/CaptureTheme"
               android:layout_width="112dp"
               android:layout_height="20dp"
               android:text="Yes"
               android:id="@+id/button2"
               android:layout_gravity="center_horizontal"
               android:onClick="sendSecond"
               android:visibility="visible"
               android:layout_alignParentBottom="true"
               android:layout_centerHorizontal="true"
               android:layout_marginBottom="165dp"
               android:layout_weight="0.01" /&gt;
  
  
           &lt;!-- The ActionBar displayed at the top --&gt;
  
           &lt;!-- The main content view where fragments are loaded --&gt;
           &lt;FrameLayout
               android:id="@+id/flContent"
               android:layout_width="match_parent"
               android:layout_height="match_parent" /&gt;
       &lt;/LinearLayout&gt;
  
       &lt;!-- The navigation drawer that comes from the left --&gt;
       &lt;!-- Note that `android:layout_gravity` needs to be set to 'start' --&gt;
       &lt;android.support.design.widget.NavigationView
           android:id="@+id/nvView"
           android:layout_width="wrap_content"
           android:layout_height="match_parent"
           android:layout_gravity="start"
           android:background="@android:color/white"
           app:menu="@menu/drawer_view" /&gt; &lt;/android.support.v4.widget.DrawerLayout&gt;
  </code></pre>
  
  <p><strong>AndroidManifest.xml</strong></p>
  
  <pre><code>&lt;Activity
      android:name="com.google.zxing.client.android.CaptureActivity"
      android:configChanges="orientation|keyboardHidden"
      android:label="ZXing ScanBar"
      android:theme="@style/Theme.AppCompat.Light.NoActionBar"
      android:windowSoftInputMode="stateAlwaysHidden"&gt;
  </code></pre>
  
  <p><strong>Styles.xml</strong></p>
  
  <pre><code>&lt;style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar"&gt;
      &lt;item name="windowActionBar"&gt;false&lt;/item&gt;
      &lt;item name="colorPrimary"&gt;#673AB7&lt;/item&gt;
      &lt;item name="colorPrimaryDark"&gt;#512DA8&lt;/item&gt;
      &lt;item name="colorAccent"&gt;#FF4081&lt;/item&gt;
      &lt;item name="windowNoTitle"&gt;true&lt;/item&gt;
  
  &lt;/style&gt;
  
  
  &lt;!-- Application theme. --&gt;
  &lt;style name="AppBaseTheme" parent="Theme.AppCompat.Light.NoActionBar"&gt;
      &lt;item name="windowActionBar"&gt;false&lt;/item&gt;
      &lt;item name="colorPrimary"&gt;#673AB7&lt;/item&gt;
      &lt;item name="windowNoTitle"&gt;true&lt;/item&gt;         
      &lt;item name="colorPrimaryDark"&gt;#512DA8&lt;/item&gt;
      &lt;item name="colorAccent"&gt;#FF4081&lt;/item&gt;
      &lt;!-- All customizations that are NOT specific to a particular API-level can go here. --&gt;    
  &lt;/style&gt;
  </code></pre>
  
  <p><strong>Toolbar.xml</strong></p>
  
  <pre><code>&lt;android.support.v7.widget.Toolbar
      xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:app="http://schemas.android.com/apk/res-auto"
      android:id="@+id/toolbar"
      android:layout_height="wrap_content"
      android:layout_width="match_parent"
      android:fitsSystemWindows="true"
      android:minHeight="?attr/actionBarSize"
      app:theme="@style/Theme.AppCompat.Light.NoActionBar"
      android:background="?attr/colorPrimaryDark"&gt;  
  &lt;/android.support.v7.widget.Toolbar&gt;
  </code></pre>