title: Views in NavigationView are not showing/not visible
body: <p>I am using Navigation view with drawer layout and a custom layout in side Navigation view as menu, and included it inside navigation view but noting is visible, i have also tried to add other type of views but nothing is showing in navigationview.
  below is the main activity xml code where i am using the drawerlayout and navigation view and main activity class</p>
  
  <p>Main Activity</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:layout_width="match_parent"
  android:layout_height="match_parent"
  android:id="@+id/Drawer"
  tools:context="com.example.minhasoft_pc.drawer.MainActivity"&gt;
  
  &lt;LinearLayout
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:weightSum="4"
      android:orientation="vertical"&gt;
  
      &lt;ImageView
          android:layout_margin="10dp"
          android:layout_gravity="center"
          android:src="@mipmap/ic_launcher_round"
          android:layout_weight="1"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content" /&gt;
      &lt;ImageView
          android:layout_margin="5dp"
          android:layout_gravity="center"
          android:src="@mipmap/ic_launcher_round"
          android:layout_weight="1"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content" /&gt;
      &lt;ImageView
          android:layout_margin="10dp"
          android:layout_gravity="center"
          android:src="@mipmap/ic_launcher_round"
          android:layout_weight="1"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content" /&gt;
  
  
  
  &lt;/LinearLayout&gt;
  
  
  &lt;android.support.design.widget.NavigationView
      android:id="@+id/nav_view"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:layout_gravity="start"
      android:fitsSystemWindows="true"
      android:layout_marginEnd="-65dp"
      android:layout_marginRight="-65dp"
      &gt;
  
      &lt;LinearLayout
          android:layout_width="match_parent"
          android:layout_height="match_parent"&gt;
  
          &lt;include layout="@layout/drawer_menu"/&gt;
  
  
      &lt;/LinearLayout&gt;
  
  
  
      &lt;/android.support.design.widget.NavigationView&gt;
  
  
      &lt;/android.support.v4.widget.DrawerLayout&gt;
  </code></pre>
  
  <p>Activity class</p>
  
  <pre><code>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);
  
  
  
     // ActionBar bar = getActionBar();
     // bar.setBackgroundDrawable(new ColorDrawable(Color.parseColor("#0000ff")));
  
  
  
      mDrawerlayout = (DrawerLayout) findViewById(R.id.Drawer) ;
      mToggle = new ActionBarDrawerToggle(this,mDrawerlayout,R.string.draweropen,R.string.drawerclosed) ;
  
  
  
      mDrawerlayout.addDrawerListener(mToggle);
      mToggle.syncState();
  
      getSupportActionBar().setDisplayHomeAsUpEnabled(true);
  }
  
  @Override
  public boolean onOptionsItemSelected(MenuItem item) {
  
      if(mToggle.onOptionsItemSelected(item))
      {
             return true ;
      }
  
      return super.onOptionsItemSelected(item);
  }
  </code></pre>
  
  <p>}</p>