title: Missing Hamburger Icon Android
body: <p>I tried searching for different answers regarding the hamburger icon, but haven't found anything similar. I'm trying to create a hamburger icon and have been following a tutorial. The code runs fine, but the icon is missing when I open it in the virtual device. Any suggestions are appreciated.</p>
  
  <p>activity_main 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:tools="http://schemas.android.com/tools"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  tools:context="com.android.navigationapp.navigationapp.MainActivity"
  android:id="@+id/drawerLayout"&gt;
  
  &lt;LinearLayout
      android:layout_width="match_parent"
      android:layout_height="match_parent"&gt;
  
      &lt;TextView
          android:text="Main Layout"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:id="@+id/textView"
          android:layout_gravity="center_vertical"
          android:textAlignment="center"
          android:textSize="24dp" /&gt;
  &lt;/LinearLayout&gt;
  
  &lt;android.support.design.widget.NavigationView
      android:layout_width="wrap_content"
      android:layout_height="match_parent"
      app:menu="@menu/navigation_menu"
      android:layout_gravity="start"&gt;
  &lt;/android.support.design.widget.NavigationView&gt;
  
  &lt;/android.support.v4.widget.DrawerLayout&gt;
  </code></pre>
  
  <p>MainActivity Java</p>
  
  <pre><code>package com.android.navigationapp.navigationapp;
  
  import android.support.v4.widget.DrawerLayout;
  import android.support.v7.app.ActionBar;
  import android.support.v7.app.ActionBarDrawerToggle;
  import android.support.v7.app.AppCompatActivity;
  import android.os.Bundle;
  import android.view.MenuItem;
  
  public class MainActivity extends AppCompatActivity {
  
  private DrawerLayout mDrawerLayout;
  private ActionBarDrawerToggle mToggle;
  
  @Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
  
      mDrawerLayout = (DrawerLayout) findViewById(R.id.drawerLayout);
      mToggle = new ActionBarDrawerToggle(this, mDrawerLayout, R.string.open, R.string.close);
  
      mDrawerLayout.addDrawerListener(mToggle);
      mToggle.syncState();
  
      getSupportActionBar().setDefaultDisplayHomeAsUpEnabled(true);
      getSupportActionBar().setHomeButtonEnabled(true);
  
  }
  
  @Override
  public boolean onOptionsItemSelected(MenuItem item) {
  
      if (mToggle.onOptionsItemSelected(item)) {
          return true;
      }
      return super.onOptionsItemSelected(item);
  }
  }
  </code></pre>