Android มาวิธีใช้ tabbed activity + The Navigation Drawer หน่อยครับ แนะนำที

MainActivity.java

package com.androidbelieve.drawerwithswipetabs;

import android.os.Bundle;
import android.support.design.widget.NavigationView;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.view.MenuItem;

public class MainActivity extends AppCompatActivity{
    DrawerLayout mDrawerLayout;
    NavigationView mNavigationView;
    FragmentManager mFragmentManager;
    FragmentTransaction mFragmentTransaction;

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

        /**
         *Setup the DrawerLayout and NavigationView
         */

             mDrawerLayout = (DrawerLayout) findViewById(R.id.drawerLayout);
             mNavigationView = (NavigationView) findViewById(R.id.shitstuff) ;

        /**
         * Lets inflate the very first fragment
         * Here , we are inflating the TabFragment as the first Fragment
         */

             mFragmentManager = getSupportFragmentManager();
             mFragmentTransaction = mFragmentManager.beginTransaction();
             mFragmentTransaction.replace(R.id.containerView,new TabFragment()).commit();
        /**
         * Setup click events on the Navigation View Items.
         */

             mNavigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
             @Override
             public boolean onNavigationItemSelected(MenuItem menuItem) {
                mDrawerLayout.closeDrawers();



                 if (menuItem.getItemId() == R.id.nav_item_sent) {
                     FragmentTransaction fragmentTransaction = mFragmentManager.beginTransaction();
                     fragmentTransaction.replace(R.id.containerView,new
SentFragment()).commit();

                 }

                if (menuItem.getItemId() == R.id.nav_item_inbox) {
                    FragmentTransaction xfragmentTransaction = mFragmentManager.beginTransaction();
                    xfragmentTransaction.replace(R.id.containerView,new
TabFragment()).commit(); }

                 return false;
            }

        });

        /**
         * Setup Drawer Toggle of the Toolbar
         */

                android.support.v7.widget.Toolbar toolbar = (android.support.v7.widget.Toolbar) findViewById(R.id.toolbar);
                ActionBarDrawerToggle mDrawerToggle = new ActionBarDrawerToggle(this,mDrawerLayout, toolbar,R.string.app_name,
                R.string.app_name);

                mDrawerLayout.setDrawerListener(mDrawerToggle);

                mDrawerToggle.syncState();

    }
}

TabFragment.java

package com.androidbelieve.drawerwithswipetabs;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.design.widget.TabLayout;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class TabFragment extends Fragment {

    public static TabLayout tabLayout;
    public static ViewPager viewPager;
    public static int int_items = 3 ;

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        /**
         *Inflate tab_layout and setup Views.
         */
            View x =  inflater.inflate(R.layout.tab_layout,null);
            tabLayout = (TabLayout) x.findViewById(R.id.tabs);
            viewPager = (ViewPager) x.findViewById(R.id.viewpager);

        /**
         *Set an Apater for the View Pager
         */
        viewPager.setAdapter(new MyAdapter(getChildFragmentManager()));

        /**
         * Now , this is a workaround ,
         * The setupWithViewPager dose't works without the runnable .
         * Maybe a Support Library Bug .
         */

        tabLayout.post(new Runnable() {
            @Override
            public void run() {
                    tabLayout.setupWithViewPager(viewPager);
                   }
        });

        return x;

    }

    class MyAdapter extends FragmentPagerAdapter{

        public MyAdapter(FragmentManager fm) {
            super(fm);
        }

        /**
         * Return fragment with respect to Position .
         */

        @Override
        public Fragment getItem(int position)
        {
          switch (position){
              case 0 : return new PrimaryFragment();
              case 1 : return new SocialFragment();
              case 2 : return new UpdatesFragment();
          }
        return null;
        }

        @Override
        public int getCount() {

            return int_items;

        }

        /**
         * This method returns the title of the tab according to the position.
         */

        @Override
        public CharSequence getPageTitle(int position) {

            switch (position){
                case 0 :
                    return "Primary";
                case 1 :
                    return "Social";
                case 2 :
                    return "Updates";
            }
                return null;
        }
    }

}

package com.androidbelieve.drawerwithswipetabs;

import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;


public class PrimaryFragment extends Fragment {

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        return inflater.inflate(R.layout.primary_layout,null);
    }
}

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="40dp"
        android:textSize="30sp"
        android:gravity="center"
        android:id="@+id/textView"
        android:layout_centerHorizontal="true"
        android:textColor="@android:color/holo_blue_dark"
        android:text="Primary\nFragment"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:autoLink="web"
        android:textSize="15sp"
        android:layout_marginTop="10dp"
        android:layout_centerHorizontal="true"
        android:text="androidbelieve.com"
        android:textColor="#000"
        android:layout_below="@+id/textView"
        android:textStyle="italic"/>

</RelativeLayout>