ViewPager+FragmentPagerAdapter+TabPageIndicator实现Tab效果（推荐）

编写布局文件代码：

activity_main.xml：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    xmlns:tools="http://schemas.android.com/tools"
    tools:context="com.example.pagerindicator_tab.MainActivity"
    >
    <com.viewpagerindicator.TabPageIndicator
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/tabPageIndicator"
        android:background="@color/colorAccent"/>
    <android.support.v4.view.ViewPager
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/viewPager"/>
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Hello"
        android:id="@+id/tv"
        android:textSize="25sp"/>
</LinearLayout><

编写TabFragment继承fragment,用来显示页面数据:

public class TabFragment extends Fragment{
    private int pos;
    @SuppressLint("ValidFragment")
    public TabFragment(int pos){  
        this.pos = pos;
    }
    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.frag,container,false);
        TextView tv = (TextView) view.findViewById(R.id.tv);
        tv.setText(TabAdapter.TITLES[pos]);
        return view;
    }
}

public class TabAdapter extends FragmentPagerAdapter{
    public static String TITLES[] = {"新朋友","群聊","公众号","商城"};
    public TabAdapter(FragmentManager fm) {
        super(fm);
    }
// viewPager填充的每个fragment页面,
    @Override
    public Fragment getItem(int position) {
        TabFragment fragment = new TabFragment(position);
        return fragment;
    }
//  Tab的数目
    @Override
    public int getCount() {
        return TITLES.length;
    }
//  填充Tab的标题
    @Override
    public CharSequence getPageTitle(int position) {
        return TITLES[position];
    }
}

编写MainActivity代码：

public class MainActivity extends FragmentActivity {
    private TabAdapter tabAdapter;
    private ViewPager viewPager;
    private TabPageIndicator tabPageIndicator;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tabAdapter = new TabAdapter(getSupportFragmentManager());
        initViews();
        viewPager.setAdapter(tabAdapter);
        tabPageIndicator.setViewPager(viewPager,0);
    }

    private void initViews(){
        viewPager =  (ViewPager) findViewById(R.id.viewPager);
        tabPageIndicator = (TabPageIndicator) findViewById(R.id.tabPageIndicator);
    }
}

关于TabPageIndicator的样式可以在style.xml中进行配置，如下：

  <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
        <!--设置TabPageIndicator样式为MyTabPageIndicator-->
        <item name="vpiTabPageIndicatorStyle">@style/MyTabPageIndicator</item>  
        <item name="android:windowNoTitle">true</item>
    </style>
    <style name="MyTabPageIndicator" parent="Widget">
        <item name="android:background">@drawable/vpi__tab_indicator</item>      <<span style="font-family: Arial, Helvetica, sans-serif;">!--设置TabPageIndicator的背景样式--></span>
        <item name="android:textSize">20sp</item>                 <!--设置TabPageIndicator中文字的大小-->
    </style>

实现的效果如下：

注：com.viewpagerindicator.TabPageIndicator需要导入相关包，在Android Studio中导入这个包，可以参见我的博客介绍：http://blog.csdn.net/csdn_blog_lcl/article/details/52744101