title: How to remove top border shadow from ActionBar
body: <p>I am working on a new Android app and for some reason, this new app (with no extra code added by myself) has a TOP border shadow on the actionbar.</p>
  
  <p>It seems as though it was added by default when I created a new project using Android Studio.</p>
  
  <p><a href="https://i.stack.imgur.com/0Ij1G.png" rel="noreferrer"><img src="https://i.stack.imgur.com/0Ij1G.png" alt="enter image description here"></a></p>
  
  <p>How do I just have a normal actionbar with only a bottom shadow?</p>
  
  <p>I have tried searching for a solution, however, all the results have people asking how to remove the bottom shadow. Usually with very specific code snippets which will remove all shadows from it, which I don't want.</p>
  
  <hr/>
  
  <h3>Edit:</h3>
  
  <p>main_activity.xml:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&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"
      xmlns:tools="http://schemas.android.com/tools"
      android:id="@+id/drawer_layout"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:fitsSystemWindows="true"
      tools:openDrawer="start"&gt;
  
      &lt;include
          layout="@layout/app_bar_main"
          android:layout_width="match_parent"
          android:layout_height="match_parent" /&gt;
  
      &lt;android.support.design.widget.NavigationView
          android:id="@+id/nav_view"
          android:layout_width="wrap_content"
          android:layout_height="match_parent"
          android:layout_gravity="start"
          android:fitsSystemWindows="true"
          app:headerLayout="@layout/nav_header_main"
          app:menu="@menu/main_drawer" /&gt;
  
  &lt;/android.support.v4.widget.DrawerLayout&gt;
  </code></pre>
  
  <p>content_main.xml:</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"
      xmlns:tools="http://schemas.android.com/tools"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:paddingBottom="@dimen/activity_vertical_margin"
      android:paddingLeft="@dimen/activity_horizontal_margin"
      android:paddingRight="@dimen/activity_horizontal_margin"
      android:paddingTop="@dimen/activity_vertical_margin"
      app:layout_behavior="@string/appbar_scrolling_view_behavior"
      tools:context="com.wer.wer.Main"
      tools:showIn="@layout/app_bar_main"&gt;
  
      &lt;TextView
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:text="Hello World!" /&gt;
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <p>nav_header_main.xml:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
      android:layout_width="match_parent"
      android:layout_height="@dimen/nav_header_height"
      android:background="@drawable/side_nav_bar"
      android:gravity="bottom"
      android:orientation="vertical"
      android:paddingBottom="@dimen/activity_vertical_margin"
      android:paddingLeft="@dimen/activity_horizontal_margin"
      android:paddingRight="@dimen/activity_horizontal_margin"
      android:paddingTop="@dimen/activity_vertical_margin"
      android:theme="@style/ThemeOverlay.AppCompat.Dark"&gt;
  
      &lt;ImageView
          android:id="@+id/imageView"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:paddingTop="@dimen/nav_header_vertical_spacing"
          android:src="@android:drawable/sym_def_app_icon" /&gt;
  
      &lt;TextView
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:paddingTop="@dimen/nav_header_vertical_spacing"
          android:text="Android Studio"
          android:textAppearance="@style/TextAppearance.AppCompat.Body1" /&gt;
  
      &lt;TextView
          android:id="@+id/textView"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:text="android.studio@android.com" /&gt;
  
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p>app_bar_main.xml:</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"
      xmlns:tools="http://schemas.android.com/tools"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:fitsSystemWindows="true"
      tools:context="com.wer.wer.Main"&gt;
  
      &lt;android.support.design.widget.AppBarLayout
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:theme="@style/AppTheme.AppBarOverlay"&gt;
  
          &lt;android.support.v7.widget.Toolbar
              android:id="@+id/toolbar"
              android:layout_width="match_parent"
              android:layout_height="?attr/actionBarSize"
              android:background="?attr/colorPrimary"
              app:popupTheme="@style/AppTheme.AppBarOverlay" /&gt;
  
      &lt;/android.support.design.widget.AppBarLayout&gt;
  
      &lt;include layout="@layout/content_main" /&gt;
  
      &lt;android.support.design.widget.FloatingActionButton
          android:id="@+id/fab"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_gravity="bottom|end"
          android:layout_margin="@dimen/fab_margin"
          android:src="@android:drawable/ic_menu_edit" /&gt;
  
  &lt;/android.support.design.widget.CoordinatorLayout&gt;
  </code></pre>
  
  <p>manifest.xml:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.wer.wer"&gt;
  
      &lt;application
          android:allowBackup="true"
          android:icon="@mipmap/ic_launcher"
          android:label="@string/app_name"
          android:supportsRtl="true"
          android:theme="@style/AppTheme"&gt;
          &lt;activity
              android:name=".Main"
              android:label="@string/app_name"
              android:theme="@style/AppTheme.NoActionBar"&gt;
              &lt;intent-filter&gt;
                  &lt;action android:name="android.intent.action.MAIN" /&gt;
  
                  &lt;category android:name="android.intent.category.LAUNCHER" /&gt;
              &lt;/intent-filter&gt;
          &lt;/activity&gt;
      &lt;/application&gt;
  
  &lt;/manifest&gt;
  </code></pre>