Android中TabLayout+ViewPager实现tab和页面联动效果

<?xml version="1.0" encoding="utf-8"?>
<relativelayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  android:id="@+id/activity_main"
  android:layout_width="match_parent"
  android:layout_height="match_parent">

  <android.support.design.widget.tablayout
    android:id="@+id/toolbar_tl_tab"
    android:layout_width="match_parent"
    android:layout_height="?attr/actionbarsize"
    android:layout_gravity="bottom"
    app:layout_scrollflags="scroll"
    app:tabindicatorcolor="@android:color/holo_green_light"
    app:tabselectedtextcolor="@android:color/holo_green_light" />

  <view
    android:layout_width="match_parent"
    android:layout_height="1dp"
    android:background="#f0f0f0" />

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

public class mainactivity extends appcompatactivity {

  private tablayout toolbar_tl_tab;
  private viewpager vp_container;
  private string[] titles = {"标题1", "标题2", "标题3", "标题4"};

  @override
  protected void oncreate(bundle savedinstancestate) {
    super.oncreate(savedinstancestate);
    setcontentview(r.layout.activity_main);
    init();
  }

  private void init() {
    toolbar_tl_tab = (tablayout) findviewbyid(r.id.toolbar_tl_tab);
    vp_container = (viewpager) findviewbyid(r.id.vp_container);
    toolbar_tl_tab.setupwithviewpager(vp_container);
    toolbar_tl_tab.settabmode(tablayout.mode_scrollable);
    vp_container.setadapter(new fragmentstatepageradapter(getsupportfragmentmanager()) {
      @override
      public fragment getitem(int position) {
        return new pagefragment();
      }

      @override
      public charsequence getpagetitle(int position) {
        return titles[position];
      }

      @override
      public int getcount() {
        return titles.length;
      }
    });
  }

}

public class pagefragment extends fragment {
  @nullable
  @override
  public view oncreateview(layoutinflater inflater, @nullable viewgroup container, @nullable bundle savedinstancestate) {
    view view = inflater.inflate(r.layout.fragment_page, null);
    return view;
  }
}

<?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">

  <textview
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center"
    android:text="页面" />
</linearlayout>

toolbar_tl_tab.settabmode(tablayout.mode_scrollable);

toolbar_tl_tab.settabmode(tablayout.mode_fixed);