Android使用ActionBar和ViewPager切换页面

演示效果如下：



项目布局如下：





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。