Navigationsansicht wird nicht angezeigt

Question

Ich vermisse etwas wirklich Grundlegendes hier.

In meinem content_passenger_home

<LinearLayout 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:orientation="vertical" 
       app:layout_behavior="@string/appbar_scrolling_view_behavior" 
       tools:context="com.mcruiseon.buseeta.PassengerHome" 
       tools:menu="passenger_home" 
       tools:showIn="@layout/app_bar_passenger_home"> 

In meinem app_bar_passenger_home

<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.mcruiseon.buseeta.PassengerHome"> 

In meinem activity_passenger_home

<android.support.v4.widget.DrawerLayout android:id="@+id/drawer_layout" 
             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:openDrawer="start"> 

    <include 
     layout="@layout/app_bar_passenger_home" 
     android:layout_width="match_parent" 
     android:layout_height="match_parent"/> 

    <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" 
     android:visibility="gone" 
     app:headerLayout="@layout/nav_header_passenger_home" 
     app:menu="@menu/activity_passenger_home_drawer" 
     /> 
</android.support.v4.widget.DrawerLayout> 

Mein passenger_home.java

public class PassengerHome extends AppCompatActivity 
     implements NavigationView.OnNavigationItemSelectedListener { 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_passenger_home); 
     Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); 
     setSupportActionBar(toolbar); 

     FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab); 
     fab.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View view) { 
       Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG) 
         .setAction("Action", null).show(); 
      } 
     }); 

     DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout); 
     ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
       this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close); 
     drawer.setDrawerListener(toggle); 
     toggle.syncState(); 

     NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view); 
     navigationView.setNavigationItemSelectedListener(this); 
    } 

    @Override 
    public void onBackPressed() { 
     DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout); 
     if (drawer.isDrawerOpen(GravityCompat.START)) { 
      drawer.closeDrawer(GravityCompat.START); 
     } else { 
      super.onBackPressed(); 
     } 
    } 

    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     // Inflate the menu; this adds items to the action bar if it is present. 
     getMenuInflater().inflate(R.menu.passenger_home, menu); 
     return true; 
    } 

    @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 
     // Handle action bar item clicks here. The action bar will 
     // automatically handle clicks on the Home/Up button, so long 
     // as you specify a parent activity in AndroidManifest.xml. 
     int id = item.getItemId(); 

     //noinspection SimplifiableIfStatement 
     if (id == R.id.action_settings) { 
      return true; 
     } 

     return super.onOptionsItemSelected(item); 
    } 

    @SuppressWarnings("StatementWithEmptyBody") 
    @Override 
    public boolean onNavigationItemSelected(MenuItem item) { 
     // Handle navigation view item clicks here. 
     int id = item.getItemId(); 

     if (id == R.id.nav_camera) { 
      // Handle the camera action 
     } else if (id == R.id.nav_gallery) { 

     } else if (id == R.id.nav_slideshow) { 

     } else if (id == R.id.nav_manage) { 

     } else if (id == R.id.nav_share) { 

     } else if (id == R.id.nav_send) { 

     } 

     DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout); 
     drawer.closeDrawer(GravityCompat.START); 
     return true; 
    } 
} 

Answer 1

bitte meinen Kommentar in Ihrer Codezeilen überprüfen

<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" 
    android:visibility="gone" // why your setting visibility gone here. 
    app:headerLayout="@layout/nav_header_passenger_home" 
    app:menu="@menu/activity_passenger_home_drawer" 
    /> 

Answer 2

dies Idealer

activity_passenger_home die Strömung sein

<?xml version="1.0" encoding="utf-8"?> 
<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"> 
    <include 
     layout="@layout/app_bar_passenger_home" 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" /> 
    <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" 
     android:layout_marginTop="@dimen/activity_vertical_margin" 
     app:headerLayout="@layout/nav_header_home" 
     app:menu="@menu/activity_home_drawer" /> 
</android.support.v4.widget.DrawerLayout> 

Jetzt im app_bar_passenger_home dies die Komponenten einschließlich, Toolbar

<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.demo.HomeActivity"> 
    <android.support.design.widget.AppBarLayout 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:theme="@style/AppTheme.AppBarOverlay"> 
     <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.PopupOverlay" /> 
    </android.support.design.widget.AppBarLayout> 
    <include layout="@layout/content_passenger_home" 
     android:id="@+id/mainContent" 
     /> 
</android.support.design.widget.CoordinatorLayout> 

Endlich Umsetzung der Home-Bildschirm in content_passenger_home wird

sein

<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" 
    app:layout_behavior="@string/appbar_scrolling_view_behavior" 
    tools:context="com.demo.HomeActivity" 
    tools:showIn="@layout/app_bar_home"> 
</RelativeLayout>