android 应用切换滑动 Android应用中利用ViewPager实现多页面滑动切换效果示例

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

android:layout_width="match_parent"

android:layout_height="match_parent"

android:orientation="vertical" >

android:id="@+id/viewPager"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_gravity="center" >

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_gravity="top" />

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 fragmentList = new ArrayList();

/** 页面title list **/

List titleList = new ArrayList();

@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 fragmentList;

private List titleList;

public myPagerAdapter(FragmentManager fm, List fragmentList, List 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 fragmentList = new ArrayList();

List titleList = new ArrayList();

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 fragmentList;

private List titleList;

public myPagerAdapter(FragmentManager fm, List fragmentList, List 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：