一段奇怪读取数据源的程序

作为一个初学者,我想爆头了也想不出个所以然来,那位大哥解说一下,谢谢,一段读取数据源程序:var products = ProductManager.GetAllProductsDisplayedOnHomePage();
            if (products.Count > 0)
            {
                dlCatalog.DataSource = products;
                dlCatalog.DataBind();
            }
----->2.
public static ProductCollection GetAllProductsDisplayedOnHomePage()
        {
       
            var dbCollection = DBProviderManager<DBProductProvider>.Provider.GetAllProductsDisplayedOnHomePage(showHidden, languageId);
            var products = DBMapping(dbCollection);
            return products;
        }
----> 3.
public abstract DBProductCollection GetAllProductsDisplayedOnHomePage(bool showHidden,
            int languageId);这三段程序是用VS转定义跟踪到的,到最后一段程序后,就没下文了,不明白怎么不见读取数据就能取到数据了???GetAllProductsDisplayedOnHomePage();--->2.GetAllProductsDisplayedOnHomePage();
...Provider.GetAllProductsDisplayedOnHomePage(showHidden, languageId);---->3.GetAllProductsDisplayedOnHomePage(bool showHidden,int languageId);
.....3.最后一段抽象方法就这样结束了,根本就没见我们平时连接数据一样读取数据嘛???