onNavigationItemSelected未在導航抽屜中調用

Question

我有一個NavigationDrawer應用，但是，onNavigationItemSelected方法未被調用。抽屜正常工作，當一個項目被選中的抽屜確實接近，但意見不加載/改變

我的主類

public class BRGO extends AppCompatActivity 
     implements NavigationView.OnNavigationItemSelectedListener { 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_brgo); 
     News initial = new News(); 
     FragmentTransaction transfer = getSupportFragmentManager().beginTransaction(); 
     transfer.replace(R.id.fragmentcontainer, initial); 
     transfer.commit(); 
     Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); 
     setSupportActionBar(toolbar); 
     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.brgo, 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(); 
     SharedPreferences sharedPref = getPreferences(Context.MODE_PRIVATE); 
     SharedPreferences.Editor editor = sharedPref.edit(); 
     //noinspection SimplifiableIfStatement 
     if (id == R.id.S14273) { 
     editor.putInt("School", 14273); 
      editor.commit(); 
      return true; 
     } 
     else if(id == R.id.S14276){ 
      editor.putInt("School", 14276); 
      editor.commit(); 
      return true; 
     } 
     else if(id == R.id.S14274){ 
      editor.putInt("School", 14274); 
      editor.commit(); 
      return true; 
     } 
     else if(id == R.id.S14271){ 
      editor.putInt("School", 14271); 
      editor.commit(); 
      return true; 
     } 
     else if(id == R.id.S14278){ 
      editor.putInt("School", 14278); 
      editor.commit(); 
      return true; 
     } 
     else if(id == R.id.S14277){ 
      editor.putInt("School", 14273); 
      editor.commit(); 
      return true; 
     } 
     else if(id == R.id.S14275){ 
      editor.putInt("School", 14275); 
      editor.commit(); 
      return true; 
     } 
     else if(id == R.id.S14272){ 
      editor.putInt("School", 14272); 
      editor.commit(); 
      return true; 
     } 
     else if(id == R.id.S14269){ 
      editor.putInt("School", 14269); 
      editor.commit(); 
      return true; 
     } 
     else if(id == R.id.S14268){ 
      editor.putInt("School", 14268); 
      editor.commit(); 
      return true; 
     } 
     else if(id == R.id.S14264){ 
      editor.putInt("School", 14264); 
      editor.commit(); 
      return true; 
     } 

     return super.onOptionsItemSelected(item); 
    } 

    @SuppressWarnings("StatementWithEmptyBody") 
    @Override 
    public boolean onNavigationItemSelected(MenuItem item) { 
     // Handle navigation view item clicks here. 
     int id = item.getItemId(); 
     Fragment fragment; 
     switch (id) { 
      case R.id.nav_News: 
       fragment = News.newInstance(); 
       break; 
      case R.id.nav_Calendar: 
       fragment = Calendar.newInstance(); 
       break; 
      case R.id.nav_Websites: 
       fragment = Websites.newInstance(); 
       break; 
      case R.id.nav_About: 
       fragment = About.newInstance(); 
      default: 
       fragment = News.newInstance(); 
       break; 
     } 
     FragmentTransaction transfer = getSupportFragmentManager().beginTransaction(); 
     transfer.replace(R.id.fragmentcontainer,fragment); 
     DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout); 
     drawer.closeDrawer(GravityCompat.START); 
     return true; 
    } 
} 

我的主要XML

<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" 
    android:background="@color/colorPrimary"> 

    <include 
     layout="@layout/app_bar_brgo" 
     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" 
     app:headerLayout="@layout/nav_header_brgo" 
     app:menu="@menu/activity_brgo_drawer" 
     app:itemTextColor="@color/colorPrimaryDark" 
     app:itemBackground="@color/colorPrimary" 
     android:background="@color/colorPrimary"/> 
</android.support.v4.widget.DrawerLayout> 

我的應用程序欄XML

<?xml version="1.0" encoding="utf-8"?> 
<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.tble.brgo.BRGO"> 

    <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:titleTextColor="@color/colorPrimaryDark" 
      app:popupTheme="@style/AppTheme.PopupOverlay" /> 

    </android.support.design.widget.AppBarLayout> 

<FrameLayout 
    android:id="@+id/fragmentcontainer" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent"> 

</FrameLayout> 

</android.support.design.widget.CoordinatorLayout> 

Answer 1

FragmentTransaction未完成而未提交。

更改此：

FragmentTransaction transfer = getSupportFragmentManager().beginTransaction(); 
transfer.replace(R.id.fragmentcontainer,fragment); 

到：

FragmentTransaction transfer = getSupportFragmentManager().beginTransaction(); 
transfer.replace(R.id.fragmentcontainer,fragment).commit();