1、添加android support包
因为上面的几个类都是在android support包中才提供,我们先添加包。
在Eclipse->Window->Android SDK Manager,选择列表中Extras->Android Support Library进行安装。下载完后在android-sdk\extras\android\support目录下,这里我们选择v4版本,进入v4目录,拷贝其中的android-support-v4.jar文件到工程的libs目录(若没有新建)下即可,编译时ADT会自动将其导入项目中。
2、新建ViewPager的layout,内容如下
<?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" > <android.support.v4.view.ViewPager android:id="@+id/viewPager" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center" > <android.support.v4.view.PagerTabStrip android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="top" /> </android.support.v4.view.ViewPager> </LinearLayout>
ViewPager用来管理layout并可以左右滑动显示各个页面数据,PagerTabStrip用来显示页面title,android:layout_gravity="top"表示title在顶部,可设置bottom等。
3、新建FragmentActivity页面
FragmentActivity页面含有ViewPager元素,可以用来显示Fragment,定义如下:
public class ViewPagerDemo extends FragmentActivity { /** 页面list **/ List<Fragment> fragmentList = new ArrayList<Fragment>(); /** 页面title list **/ List<String> titleList = new ArrayList<String>(); @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.view_pager_demo); ViewPager vp = (ViewPager)findViewById(R.id.viewPager); fragmentList.add(new ViewPagerFragment1("页面1")); fragmentList.add(new ViewPagerFragment1("页面2")); fragmentList.add(new ViewPagerFragment1("页面3")); titleList.add("title 1 "); titleList.add("title 2 "); titleList.add("title 3 "); vp.setAdapter(new myPagerAdapter(getSupportFragmentManager(), fragmentList, titleList)); } /** * 定义适配器 */ class myPagerAdapter extends FragmentPagerAdapter { private List<Fragment> fragmentList; private List<String> titleList; public myPagerAdapter(FragmentManager fm, List<Fragment> fragmentList, List<String> titleList){ super(fm); this.fragmentList = fragmentList; this.titleList = titleList; } /** * 得到每个页面 */ @Override public Fragment getItem(int arg0) { return (fragmentList == null || fragmentList.size() == 0) ? null : fragmentList.get(arg0); } /** * 每个页面的title */ @Override public CharSequence getPageTitle(int position) { return (titleList.size() > position) ? titleList.get(position) : ""; } /** * 页面的总个数 */ @Override public int getCount() { return fragmentList == null ? 0 : fragmentList.size(); } } }
其中的myPagerAdapter集成自ragmentPagerAdapter,为ViewPager提供数据源。
onCreate函数得到ViewPager实例并设置数据源,getSupportFragmentManager表示得到Fragment管理器。ViewPagerFragment1表示具体的页面,见下面介绍。
4、新建Fragment页面
Fragment页面即为左右滑动需要显示的页面,新建类集成Fragment,并重写onCreateView函数即可。onCreateView函数相当于Activity的onCreate函数。如下:
public class ViewPagerFragment1 extends Fragment { private String text; private TextView tv = null; public ViewPagerFragment1(String text){ super(); this.text = text; } /** * 覆盖此函数,先通过inflater inflate函数得到view最后返回 */ @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View v = inflater.inflate(R.layout.view_pager_fragment_demo1, container, false); tv = (TextView)v.findViewById(R.id.viewPagerText); tv.setText(text); return v; } }
5、示例工程代码:
package cn.trinea.android.demo; 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.view.ViewPager; public class ViewPagerDemo extends BaseFragmentActivity { private static int TOTAL_COUNT = 3; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState, R.layout.view_pager_demo); ViewPager vp = (ViewPager)findViewById(R.id.view_pager); List<Fragment> fragmentList = new ArrayList<Fragment>(); List<String> titleList = new ArrayList<String>(); for (int i = 0; i < TOTAL_COUNT; i++) { ViewPagerFragment viewPagerFragment1 = new ViewPagerFragment(); Bundle bundle = new Bundle(); bundle.putInt("upImageId", 0); bundle.putString("text", "Page " + i); viewPagerFragment1.setArguments(bundle); titleList.add("title " + i); fragmentList.add(viewPagerFragment1); } vp.setAdapter(new myPagerAdapter(getSupportFragmentManager(), fragmentList, titleList)); } class myPagerAdapter extends FragmentPagerAdapter { private List<Fragment> fragmentList; private List<String> titleList; public myPagerAdapter(FragmentManager fm, List<Fragment> fragmentList, List<String> titleList) { super(fm); this.fragmentList = fragmentList; this.titleList = titleList; } @Override public Fragment getItem(int arg0) { return (fragmentList == null || fragmentList.size() == 0) ? null : fragmentList.get(arg0); } @Override public CharSequence getPageTitle(int position) { return (titleList.size() > position) ? titleList.get(position) : ""; } @Override public int getCount() { return fragmentList == null ? 0 : fragmentList.size(); } } }
简单效果如下: