左右滑动切换Activity

package misc.demo;import java.util.ArrayList;import android.app.ActivityGroup;import android.content.Intent;import android.os.Bundle;import android.support.v4.view.PagerAdapter;import android.support.v4.view.ViewPager;import android.view.View;import android.view.Window;public class MainActivity extends ActivityGroup {private View oneView;private View twoView;private View threeView;private ArrayList<View> views;private ViewPager mViewPager;//多页面滑动切换效果/** Called when the activity is first created. */@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);requestWindowFeature(Window.FEATURE_NO_TITLE);setContentView(R.layout.main);views = new ArrayList<View>();mViewPager = (ViewPager)findViewById(R.id.main_viewpager);            mViewPager.setOnPageChangeListener(null);initView();addViews();PagerAdapter mPagerAdapter = new PagerAdapter() {@Overridepublic boolean isViewFromObject(View arg0, Object arg1) {return arg0 == arg1;}@Overridepublic int getCount() {return views.size();}@Overridepublic void destroyItem(View container, int position, Object object) {((ViewPager)container).removeView(views.get(position));}@Overridepublic Object instantiateItem(View container, int position) {((ViewPager)container).addView(views.get(position));return views.get(position);}};mViewPager.setAdapter(mPagerAdapter);}/** * 将相应的Activity转换成View对象 */public void initView(){oneView=getViews(OneActivity.class,"one");twoView=getViews(TwoActivity.class,"two");threeView=getViews(ThreeActivity.class,"three");}/** * 将转换成View后的Activity添加到列表中 */public void addViews(){views.add(oneView);views.add(twoView);views.add(threeView);}/** * 获取要跳转的Activity对应的View * @param cls目的Activity * @param pageid目的Activity的唯一id * @return 返回一个View类型的变量 */public View getViews(Class<?> cls,String pageid){return getLocalActivityManager().startActivity(pageid, new Intent(MainActivity.this,cls).addFlags(Intent.FLAG_ACTIVITY_BROUGHT_TO_FRONT)).getDecorView();}}