android - GridView Items 更改并最终在 Scrolling 上消失

Question

这是我BaseAdapater正在使用的课程ViewHolder。

public class CategoryAdapter extends BaseAdapter {

    private Context         mContext;
    public int[] mThumbIds = {R.drawable.shoes,R.drawable.dress,R.drawable.purse,
            R.drawable.shoes,R.drawable.dress,R.drawable.purse ,
            R.drawable.shoes,R.drawable.dress,R.drawable.purse  };


    public WishbookCategoryAdapter(Context c){

        mContext = c;
    }

    @Override
    public int getCount() {
        return mThumbIds.length;
    }

    @Override
    public Object getItem(int position) {
        return mThumbIds[position];
    }

    @Override
    public long getItemId(int position) {
        return (long)position;
    }

    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
        ViewHolder holder = null;

        if(convertView==null){
            holder = new ViewHolder();
            LayoutInflater li = (LayoutInflater)mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = li.inflate(R.layout.wishbook_gridview_items, null);

            holder.Category  = (TextView)convertView.findViewById(R.id.wishbook_grid_category);         
            holder.items     = (TextView)convertView.findViewById(R.id.wishbook_grid_category_number);          
            holder.iv        = (ImageView)convertView.findViewById(R.id.wishbook_category_image);

            convertView.setTag(holder);
        }
        else
        {
            holder = (ViewHolder)convertView.getTag();
        }       
        holder.iv.setImageDrawable(mContext.getResources().getDrawable(mThumbIds[position]));
        holder.iv.setScaleType(ScaleType.FIT_XY);
        holder.Category.setText("Category");
        holder.items.setText("items");

        return convertView;
    }

     private static class ViewHolder {
         protected ImageView iv;
         protected TextView Category;
         protected TextView items;
    }


}