Android ViewPager实现轮播图效果

public class MyViewPagerAdapter extends PagerAdapter {

private List<ImageView> mList;

public MyViewPagerAdapter(List<ImageView> mList){

 this.mList=mList;

}
//当要显示的图片进行缓存时，会调用这个方法进行显示图片的初始化
//我们将要显示的ImageView加入到ViewGroup中

public Object instantiateItem(ViewGroup container, int position) {
 // TODO Auto-generated method stub
 container.addView(mList.get(position));

 return mList.get(position);

}

@Override
//PagerAdapter只缓存三张要显示的图片，如果滑动的图片超出了缓存的范围，就会调用这个方法，将图片销毁
public void destroyItem(ViewGroup container, int position, Object object) {
 // TODO Auto-generated method stub
 container.removeView(mList.get(position));
}
//获取要滑动的控件的数量，
public int getCount() {
 // TODO Auto-generated method stub
 return mList.size();
}

//来判断显示的是否是同一张照片，这个我们将两个图片对比 再返回
public boolean isViewFromObject(View arg0, Object arg1) {
 // TODO Auto-generated method stub
 return arg0==arg1;
}

 }

<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.support.v4.view.ViewPager
 android:id="@+id/vp"
 android:layout_width="match_parent"
 android:layout_height="200dp" />

<LinearLayout
 android:layout_width="match_parent"
 android:layout_height="wrap_content"
 android:layout_alignBottom="@id/vp"
 android:background="#33000000"
 android:orientation="vertical"
 android:paddingBottom="10dp" >

 <LinearLayout
  android:id="@+id/ll_points"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:gravity="center_horizontal"
  android:orientation="horizontal"
  android:paddingBottom="10dp" >
 </LinearLayout>
</LinearLayout>

</RelativeLayout>

public class MainActivity extends Activity {

private ViewPager mVp;
//private TextView tvTitle;
private LinearLayout llPoints;
//private String[] titles;// 存放所有要显示的标题
private int[] images;// 存放所有要显示的图片资源id
private List<ImageView> list=new ArrayList<ImageView>();;// 存放要显示在ViewPager对象中的所有Imageview对象
private int prevPosition = 0;

private Handler handler = new Handler() {

 @SuppressLint("HandlerLeak") 
 public void handleMessage(android.os.Message msg) {

  switch (msg.what) {
  case 0:
   // 得到mvp当前页面的索引
   int currentItem = mVp.getCurrentItem();
   // 要显示的下一个页面的索引
   currentItem++;
   // 设置ViewPager显示的页面
   mVp.setCurrentItem(currentItem % list.size());

   break;

  default:
   break;
  }
 };
};

@SuppressWarnings("deprecation")
protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 initView(); 
 // titles = getTitles();
 images=getImages();
 for (int i = 0; i < images.length; i++) {
  ImageView iv=new ImageView(this);
  iv.setBackgroundResource(images[i]);
  list.add(iv);
  //根据图片的数量生成相对应的数量的小圆点
  final View view=new View(this);
  view.setBackgroundResource(R.drawable.login__05);
  DisplayMetrics metrics=new DisplayMetrics();
  float width=TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_PX,30, metrics);
  float height=TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_PX, 30, metrics);
  LinearLayout.LayoutParams params=new LinearLayout.LayoutParams((int)width,(int)height);
  params.leftMargin=5;
  view.setLayoutParams(params);
  llPoints.addView(view);
 }
 //设置第一页显示的标题
 //tvTitle.setText(titles[0]);
 //设置第一页的时候，小圆点显示的背景图
 llPoints.getChildAt(0).setBackgroundResource(R.drawable.login__03);
 //下面封装viewpager的适配器
 MyViewPagerAdapter adapter=new MyViewPagerAdapter(list);
 mVp.setAdapter(adapter);

 //设置ViewPager对象页面变化时的监听
 mVp.setOnPageChangeListener(new OnPageChangeListener() {

  @Override
  //当下一个页面被选择的时候
  public void onPageSelected(int arg0) {
   // TODO Auto-generated method stub
   //tvTitle.setText(titles[arg0%list.size()]);

   llPoints.getChildAt(prevPosition).setBackgroundResource(R.drawable.login__05);

   llPoints.getChildAt(arg0).setBackgroundResource(R.drawable.login__03);

   //把当前点位置做为下一次变化的前一个点的位置
   prevPosition=arg0;
  }

  @Override
  public void onPageScrolled(int arg0, float arg1, int arg2) {
   // TODO Auto-generated method stub

  }

  @Override
  public void onPageScrollStateChanged(int arg0) {
   // TODO Auto-generated method stub

  }
 });

 new Thread(new Runnable() {

  @Override
  public void run() {
   // TODO Auto-generated method stub
   while (true) {

   SystemClock.sleep(3000);

   handler.sendEmptyMessage(0);

   }
  }
 }).start();


}

private void initView() {
 // TODO Auto-generated method stub
 mVp = (ViewPager) findViewById(R.id.vp);
 //tvTitle = (TextView) findViewById(R.id.tv_title);
 llPoints = (LinearLayout) findViewById(R.id.ll_points);
}

private int[] getImages(){

 return new int[]{R.drawable.banner_01,R.drawable.banner_02,R.drawable.banner_03};


}

}