Android使用ViewPager实现无限滑动效果

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="match_parent"
 android:layout_height="match_parent">

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

public class MainActivity extends AppCompatActivity {

 private ViewPager mViewPager;
 private ViewPagerAdapter mAdapter;
 private int[] images; // 图片资源数组

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  initView(); // 初始化视图
  initData(); // 初始化数据
 }

 /**
  * 初始化视图
  */
 private void initView() {
  mViewPager = (ViewPager) findViewById(R.id.view_pager);
 }

 /**
  * 初始化数据
  */
 private void initData() {
  images = new int[]{R.mipmap.image1, R.mipmap.image2};
  mAdapter = new ViewPagerAdapter(this, images);
  mViewPager.setAdapter(mAdapter);

  // 将ViewPager定位到中间页（Short.MAX_VALUE/2附近的图片资源数组第1个元素对应的页面）
  // 目的：1.图片个数 >1 才轮播 2.定位到中间页，向左向右都可滑
  if(images.length > 1) {
   mViewPager.setCurrentItem(((Short.MAX_VALUE / 2) / images.length) * images.length, false);
  }
 }
}

/**
 * @ClassName: ViewPagerAdapter
 * @Description: ViewPager适配器
 * @Author Wangnan
 * @Date 2016/9/1
 */
public class ViewPagerAdapter extends PagerAdapter{

 private Context mContext;
 private int[] mImages; // 图片资源ID数组
 private List<ImageView> mImageViews; // ImageView集合

 public ViewPagerAdapter(Context context, int[] images){
  mContext = context;
  mImages = images;
  mImageViews = new ArrayList<>();
  initImageViews(mImages);
 }

 /**
  * 初始化ImageViews集合
  * @param imageIds
  */
 private void initImageViews(int[] imageIds) {

  // 根据图片资源数组填充ImageViews集合
  for(int i = 0 ; i < imageIds.length ; i++){
   ImageView mImageView = new ImageView(mContext);
   mImageView.setImageResource(imageIds[i]);
   mImageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
   mImageViews.add(mImageView);
  }

  // ImageViews集合中的图片个数在[2,3]时会存在问题，递归再次填充一遍
  if(mImageViews.size() > 1 && mImageViews.size() < 4){
   initImageViews(imageIds);
  }
 }

 @Override
 public int getCount() {
  return mImageViews.size() <=1 ? mImageViews.size() : Short.MAX_VALUE;
 }

 @Override
 public boolean isViewFromObject(View view, Object object) {
  return view == object;
 }

 @Override
 public Object instantiateItem(ViewGroup container, int position) {
  ImageView mImageView = mImageViews.get(position % mImageViews.size());
  container.addView(mImageView);
  return mImageView;
 }

 @Override
 public void destroyItem(ViewGroup container, int position, Object object) {
  container.removeView((View)object);
 }
}

 /**
  * 初始化ImageViews集合
  * @param imageIds
  */
 private void initImageViews(int[] imageIds) {

  ......

  // ImageViews集合中的图片个数在[2,3]时会存在问题，递归再次填充一遍
  if(mImageViews.size() > 1 && mImageViews.size() < 4){
   initImageViews(imageIds);
  }
 }

 @Override
 public int getCount() {
  return mImageViews.size() <=1 ? mImageViews.size() : Short.MAX_VALUE;
 }