android design库之TabLayout的用法

compile 'com.android.support:appcompat-v7:23.4.0'
compile 'com.android.support:design:23.4.0'

<?xml version="1.0" encoding="utf-8"?>
<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" >
<android.support.design.widget.TabLayout
android:id="@+id/sliding_tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Hello World!" />
<android.support.v4.view.ViewPager
android:id="@+id/viewpager"
android:layout_width="match_parent"
android:layout_height="0px"
android:layout_weight="1"
android:background="@android:color/white" />

</LinearLayout>

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

public class SimpleFragmentAdapter extends FragmentPagerAdapter {
final int PAGE_COUNT = 3;
private String tabTitles[]  = new String[]{"tabl","tab2","tab2"};
private Context context;
public SimpleFragmentAdapter(FragmentManager fm,Context context) {
super(fm);
this.context = context;
}

@Override
public Fragment getItem(int position) {
return fragment.getInstance(position);
}

@Override
public int getCount() {
return PAGE_COUNT;
}

@Override
public CharSequence getPageTitle(int position) {
return tabTitles[position];
}
}

public class fragment extends Fragment {
public static  String tag = "fragment";
private int num;
public static fragment getInstance(int num){
Bundle bundle = new Bundle();
bundle.putInt(tag,num);
fragment fg = new fragment();
fg.setArguments(bundle);
return fg;
}

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
num = getArguments().getInt(tag);
}

@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_content, container, false);
TextView tv = (TextView)view;
tv.setText("Fragment++"+num);
return view;
}

public class MainActivity extends AppCompatActivity {
private SimpleFragmentAdapter fragmentAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
fragmentAdapter = new SimpleFragmentAdapter(getSupportFragmentManager(), this);
ViewPager viewPager = (ViewPager) findViewById(R.id.viewpager);
viewPager.setAdapter(fragmentAdapter);
TabLayout tabLayout = (TabLayout) findViewById(R.id.sliding_tabs);
tabLayout.setupWithViewPager(viewPager);
tabLayout.setTabMode(TabLayout.MODE_FIXED);
}
}