How to Cache PagerAdapter Item

[SingleJie]

public class SimpleGalleryAdapter extends PagerAdapter {

private List<T> mDatas;
private String imgFieldName;
private SparseArray<ImageView> mCaches = new SparseArray<>();
private String host;
private OnImageLoadListener<T> mListener;

@Override
public int getCount() {
    return EmptyUtils.emptyOfList(mDatas) ? 0 : mDatas.size();
}

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

@Override
public Object instantiateItem(ViewGroup container, int position) {

    Context context = container.getContext();
    ImageView img_display = mCaches.get(position);

    if (img_display == null) {
        img_display = new ImageView(context);
        img_display.setScaleType(ImageView.ScaleType.CENTER_CROP);
        mCaches.put(position, img_display);
    }

    T mItem = mDatas.get(position);

    if (mListener != null) {
         mListener.onImageLoad(img_display, mItem, imgFieldName, host);
    }
    container.addView(img_display);
    return img_display;
}

@Override
public void destroyItem(ViewGroup container, int position, Object object) {
    if (mCaches.keyAt(position) != -1) {
        container.removeView(mCaches.get(position));
        mCaches.remove(position);
    }
}

public SimpleGalleryAdapter(List<T> mDatas, String host, String imgFieldName, OnImageLoadListener<T> mListener) {
    this.mDatas = mDatas;
    this.imgFieldName = imgFieldName;
    this.host = host;
    this.mListener = mListener;
}

public SimpleGalleryAdapter(List<T> mDatas, String host, String imgFieldName) {
    this.mDatas = mDatas;
    this.imgFieldName = imgFieldName;
    this.host = host;
    this.mListener = new GlideImageLoader<T>();
}

}

that is my adapter , I user ViewPager no error , but use LoopViewPager throw this error
The specified child already has a parent. You must call removeView() on the child's parent first.