灵活使用Android中ActionBar和ViewPager切换页面

本文实例讲述了Android使用ActionBar和ViewPager切换页面，分享给大家供大家参考。具体如下：
运行效果截图如下：

项目布局如下：

具体代码如下：

MainActivity.java代码

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));
  }

}

下边是四个fragment

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);
  }
}

activity_main.xml

<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>

下边是四个fragment的布局文件

<?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>

其他三个都一样只是文件名和里边的内容改变了一下。

希望本文所述对大家学习Android软件编程有所帮助。