灵活使用Android中ActionBar和ViewPager切换页面

import java.util.ArrayList;import java.util.List;import android.os.Bundle;import android.support.v4.app.Fragment;import android.support.v4.app.FragmentManager;import android.support.v4.app.FragmentPagerAdapter;import android.support.v4.app.FragmentTransaction;import android.support.v4.view.ViewPager;import android.support.v4.view.ViewPager.OnPageChangeListener;import android.support.v7.app.ActionBar;import android.support.v7.app.ActionBar.Tab;import android.support.v7.app.ActionBar.TabListener;import android.support.v7.app.ActionBarActivity;import com.xuliugen.fragment.ChatFragment;import com.xuliugen.fragment.FriendFragment;import com.xuliugen.fragment.MomentFragment;import com.xuliugen.fragment.MoreFragment;public class MainActivity extends ActionBarActivity implements TabListener,OnPageChangeListener {  private List<MyTab> tabsList = new ArrayList<MainActivity.MyTab>(4);  private ViewPager viewPager;// ViewPager用于存放fragment  private ActionBar actionBar;  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    // 添加4个fragment到自定义的Tab中去    tabsList.add(new MyTab("聊天", ChatFragment.class));    tabsList.add(new MyTab("朋友", FriendFragment.class));    tabsList.add(new MyTab("时刻", MomentFragment.class));    tabsList.add(new MyTab("更多", MoreFragment.class));    initActionBar();  }  private void initActionBar() {    // 找到viewpager    viewPager = (ViewPager) this.findViewById(R.id.viewpager);    actionBar = getSupportActionBar(); // 获得v7中的ActionBar    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);// 设置为导航模式    // 通过循环遍历将创建的四个Tab加入到actionBar中    for (MyTab tab : tabsList) {      Tab t = actionBar.newTab(); // 使用v7下边的Tab      t.setText(tab.getText());      t.setTabListener(this);// 设置TabListener监听器      actionBar.addTab(t);    }    viewPager.setAdapter(new TabFragmentPagerAdapter(getSupportFragmentManager()));    viewPager.setOnPageChangeListener(this);  }  /**   * 封装一个Tab的类   *    * tab的文字   *    * tab所包含的Class   */  class MyTab {    private String text; // 标题的文字    private Class fragment;// 每一个tab所对应的页面fragment    public String getText() {      return text;    }    public void setText(String text) {      this.text = text;    }    public Class getFragment() {      return fragment;    }    public void setFragment(Class fragment) {      this.fragment = fragment;    }    /**     * 两个参数的构造方法，便于创建一个对象     *      * @param string     * @param fragment     */    public MyTab(String string, Class fragment) {      this.text = string;      this.fragment = fragment;    }  }  /**   * 为viewpager设置的适配器   */  class TabFragmentPagerAdapter extends FragmentPagerAdapter {    public TabFragmentPagerAdapter(FragmentManager fm) {      super(fm);    }    @Override    public Fragment getItem(int i) {      try {        return (Fragment) tabsList.get(i).getFragment().newInstance();      } catch (InstantiationException e) {        e.printStackTrace();      } catch (IllegalAccessException e) {        e.printStackTrace();      }      return null;    }    @Override    public int getCount() {      return tabsList.size();    }  }  /************* 下边是TabListener所实现的方法 ***********************/  /**   * 当Tab被双次选中   */  @Override  public void onTabReselected(Tab tab, FragmentTransaction fragmentTransaction) {  }  /**   * 当Tab被单次选中   */  @Override  public void onTabSelected(Tab tab, FragmentTransaction fragmentTransaction) {    viewPager.setCurrentItem(tab.getPosition());  }  @Override  public void onTabUnselected(Tab tab, FragmentTransaction fragmentTransaction) {  }  /**************** 下边是OnPageChangeListener实现的方法 ****************/  @Override  public void onPageScrollStateChanged(int i) {  }  @Override  public void onPageScrolled(int i, float arg1, int arg2) {  }  @Override  public void onPageSelected(int i) {    actionBar.selectTab(actionBar.getTabAt(i));  }}

public class ChatFragment extends Fragment {  @Override  public View onCreateView(LayoutInflater inflater, ViewGroup container,      Bundle savedInstanceState) {    return inflater.inflate(R.layout.fragment_friends, container, false);  }}public class FriendFragment extends Fragment {  @Override  public View onCreateView(LayoutInflater inflater, ViewGroup container,      Bundle savedInstanceState) {    return inflater.inflate(R.layout.fragment_chat, container, false);  }}public class MomentFragment extends Fragment {  @Override  public View onCreateView(LayoutInflater inflater, ViewGroup container,      Bundle savedInstanceState) {    return inflater.inflate(R.layout.fragment_moment, container, false);  }}public class MoreFragment extends Fragment {  @Override  public View onCreateView(LayoutInflater inflater, ViewGroup container,      Bundle savedInstanceState) {    return inflater.inflate(R.layout.fragment_more, container, false);  }}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"  xmlns:tools="http://schemas.android.com/tools"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:paddingBottom="@dimen/activity_vertical_margin"  android:paddingLeft="@dimen/activity_horizontal_margin"  android:paddingRight="@dimen/activity_horizontal_margin"  android:paddingTop="@dimen/activity_vertical_margin"  tools:context=".MainActivity" >  <android.support.v4.view.ViewPager    android:id="@+id/viewpager"    android:layout_width="fill_parent"    android:layout_height="fill_parent" >  </android.support.v4.view.ViewPager></RelativeLayout>

<?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="fill_parent"  android:orientation="vertical" >  <TextView    android:id="@+id/textView"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:layout_gravity="center_horizontal"    android:text="聊天" >  </TextView></LinearLayout>