替換ViewPager與新片段

我有一個應用程序，其中我的MainActivity有一個viewpager和TabLayout與三個片段（片段a，b和c）。我有一個菜單項，當選擇我想打開一個新的單獨的片段（片段d）重疊我的viewpager一個tablayout。當我點擊我的菜單選項片段d出現，但片段a，b或c仍然在後臺。替換ViewPager與新片段

What is happening

What I want to do

MainActivity.Java

public class MainActivity extends AppCompatActivity { 

    private DrawerLayout mDrawer; 
    private Toolbar toolbar; 
    private NavigationView nvDrawer; 
    private ViewPager viewPager; 
    private TabLayout tabLayout; 
    private ActionBarDrawerToggle drawerToggle; 
    private static String TAG = "MainActivity"; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 

     viewPager = (ViewPager) findViewById(R.id.viewpager); 
     BookShelfPagerAdapter bookShelfPagerAdapter = new BookShelfPagerAdapter(getApplicationContext(), getSupportFragmentManager()); 
     viewPager.setAdapter(bookShelfPagerAdapter); 

     tabLayout = (TabLayout) findViewById(R.id.tab_layout); 
     tabLayout.setupWithViewPager(viewPager); 
    } 

    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     MenuInflater inflater = getMenuInflater(); 
     inflater.inflate(R.menu.menu_book_list, menu); 
     return true; 
    } 

    @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 
      case R.id.action_discover: 
       Fragment discoverFragment = new DiscoverFragment(); 
       this.getSupportFragmentManager() 
         .beginTransaction() 
         .add(R.id.flContent, discoverFragment) 
         .addToBackStack(null) 
         .commit(); 

      return true; 
     return super.onOptionsItemSelected(item); 
    } 
}

XML佈局：MainAcitvity

<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:app="http://schemas.android.com/apk/res-auto" 
    android:id="@+id/drawer_layout" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent"> 

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

     <!-- This LinearLayout represents the contents of the screen --> 
     <LinearLayout 
      android:layout_width="match_parent" 
      android:layout_height="match_parent" 
      android:orientation="vertical"> 

      <!-- The ActionBar displayed at the top --> 
      <include 
       layout="@layout/toolbar" 
       android:layout_width="match_parent" 
       android:layout_height="wrap_content" /> 


      <android.support.design.widget.TabLayout 
       android:id="@+id/tab_layout" 
       android:layout_width="match_parent" 
       android:layout_height="wrap_content" /> 
      <!-- The main content view where fragments are loaded --> 


      <android.support.v4.view.ViewPager 
       android:id="@+id/viewpager" 
       android:layout_width="match_parent" 
       android:layout_height="match_parent" /> 


     </LinearLayout> 
    </FrameLayout> 

    <!-- The navigation drawer that comes from the left --><!-- Note that `android:layout_gravity` needs to be set to 'start' --> 
    <android.support.design.widget.NavigationView 
     android:id="@+id/nvView" 
     android:layout_width="wrap_content" 
     android:layout_height="match_parent" 
     android:layout_gravity="start" 
     android:background="@android:color/white" 
     app:headerLayout="@layout/nav_header" 
     app:menu="@menu/drawer_view" /> 
</android.support.v4.widget.DrawerLayout>

來源

2017-07-03 Antonio Rosario