Use of ViewPager and Fragment in Android

Small case

In XML

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

Create Fragment

 fragments = new ArrayList<>();
 ConversationFragment fragment1 = new ConversationFragment();
 GroupFragment fragment2 = new GroupFragment();
 SearchFragment fragment3 = new SearchFragment();
 fragments.add(fragment1);
 fragments.add(fragment2);
 fragments.add(fragment3);
 adapter = new MainPagerAdapter(getSupportFragmentManager(), fragments);
 viewPager.setAdapter(adapter);

adapter

public class MainPagerAdapter extends FragmentPagerAdapter{

  List<Fragment> fragmentList;

  public MainPagerAdapter(FragmentManager fm, List<Fragment> fragmentList) {
    super(fm);
    this.fragmentList = fragmentList;
  }

  @Override
  public Fragment getItem(int position) {
    return fragmentList.get(position);
  }

  @Override
  public int getCount() {
    return fragmentList.size();
  }
}

OnPageChangeListener

viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
  @Override
  public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
    int distance = positionOffsetPixels / 3;
    //1 Dan fragment Slide, here's position Actually before 1 A 
    ViewPropertyAnimator.animate(v_indicate_line).translationX(distance + position * v_indicate_line.getWidth()).setDuration(0);
  }

  @Override
  public void onPageSelected(int position) {
    textLightAndSize();
  }


  @Override
  public void onPageScrollStateChanged(int state) {

  }
});

Cooperate with other click events

// Here is the note setCurrentItem Usage of 
switch (view.getId()) {
  case R.id.ly_conversation:
    viewPager.setCurrentItem(0);
    break;
  case R.id.ly_group:
    viewPager.setCurrentItem(1);
    break;
  case R.id.ly_search:
    viewPager.setCurrentItem(2);
    break;
}

Official case

R.layout.fragment_pager

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:padding="4dip"
    android:gravity="center_horizontal"
    android:layout_width="match_parent" android:layout_height="match_parent">

  <android.support.v4.view.ViewPager
      android:id="@+id/pager"
      android:layout_width="match_parent"
      android:layout_height="0px"
      android:layout_weight="1">
  </android.support.v4.view.ViewPager>

  <LinearLayout android:orientation="horizontal"
      android:gravity="center" android:measureWithLargestChild="true"
      android:layout_width="match_parent" android:layout_height="wrap_content"
      android:layout_weight="0">
    <Button android:id="@+id/goto_first"
      android:layout_width="wrap_content" android:layout_height="wrap_content"
      android:text="@string/first">
    </Button>
    <Button android:id="@+id/goto_last"
      android:layout_width="wrap_content" android:layout_height="wrap_content"
      android:text="@string/last">
    </Button>
  </LinearLayout>
</LinearLayout>

R.layout.fragment_pager_list

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="vertical"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:background="@android:drawable/gallery_thumb">

  <TextView android:id="@+id/text"
    android:layout_width="match_parent" android:layout_height="wrap_content"
    android:gravity="center_vertical|center_horizontal"
    android:textAppearance="?android:attr/textAppearanceMedium"
    android:text="@string/hello_world"/>

  <!-- The frame layout is here since we will be showing either
  the empty view or the list view. -->
  <FrameLayout
    android:layout_width="match_parent"
    android:layout_height="0dip"
    android:layout_weight="1" >
    <!-- Here is the list. Since we are using a ListActivity, we
       have to call it "@android:id/list" so ListActivity will
       find it -->
    <ListView android:id="@android:id/list"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:drawSelectorOnTop="false"/>

    <!-- Here is the view to show if the list is emtpy -->
    <TextView android:id="@android:id/empty"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:textAppearance="?android:attr/textAppearanceMedium"
      android:text="No items."/>

  </FrameLayout>

</LinearLayout>

public class FragmentPagerSupport extends FragmentActivity {
  static final int NUM_ITEMS = 10;

  MyAdapter mAdapter;

  ViewPager mPager;

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

    mAdapter = new MyAdapter(getSupportFragmentManager());

    mPager = (ViewPager)findViewById(R.id.pager);
    mPager.setAdapter(mAdapter);

    // Watch for button clicks.
    Button button = (Button)findViewById(R.id.goto_first);
    button.setOnClickListener(new OnClickListener() {
      public void onClick(View v) {
        mPager.setCurrentItem(0);
      }
    });
    button = (Button)findViewById(R.id.goto_last);
    button.setOnClickListener(new OnClickListener() {
      public void onClick(View v) {
        mPager.setCurrentItem(NUM_ITEMS-1);
      }
    });
  }

  public static class MyAdapter extends FragmentPagerAdapter {
    public MyAdapter(FragmentManager fm) {
      super(fm);
    }

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

    @Override
    public Fragment getItem(int position) {
      return ArrayListFragment.newInstance(position);
    }
  }

  public static class ArrayListFragment extends ListFragment {
    int mNum;

    /**
     * Create a new instance of CountingFragment, providing "num"
     * as an argument.
     */
    static ArrayListFragment newInstance(int num) {
      ArrayListFragment f = new ArrayListFragment();

      // Supply num input as an argument.
      Bundle args = new Bundle();
      args.putInt("num", num);
      f.setArguments(args);

      return f;
    }

    /**
     * When creating, retrieve this instance's number from its arguments.
     */
    @Override
    public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      mNum = getArguments() != null ? getArguments().getInt("num") : 1;
    }

    /**
     * The Fragment's UI is just a simple text view showing its
     * instance number.
     */
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
      View v = inflater.inflate(R.layout.fragment_pager_list, container, false);
      View tv = v.findViewById(R.id.text);
      ((TextView)tv).setText("Fragment #" + mNum);
      return v;
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
      super.onActivityCreated(savedInstanceState);
      setListAdapter(new ArrayAdapter<String>(getActivity(),
          android.R.layout.simple_list_item_1, Cheeses.sCheeseStrings));
    }

    @Override
    public void onListItemClick(ListView l, View v, int position, long id) {
      Log.i("FragmentList", "Item clicked: " + id);
    }
  }
}

Attention

fragment is not available for Activity prior to 3.0. In order to use fragment (in supportV4), FragmentActivity came into being. FragmentActivity inherits from Activity.

The above is the whole content of this article, hoping to help everyone learn Android software programming.