当前文件： SmallBusinessStarterKit/App_Code/Catalog/SqlCatalogProvider.cs[6K，2009-6-12 11:54:21]，打开代码结构图

		            
  1using System;
  2using System.Configuration;
  3using System.Web.Configuration;
  4using System.Data;
  5using System.Data.SqlClient;
  6using System.Collections.Generic;
  7 /**//// <summary>
  8 ///提供访问SQL Server数据库的方法
  9 /// </summary>
 10public class SqlCatalogProvider : CatalogProvider
 11...{
 12    //从Web.Config配置文件中获取连接字符串信息。
 13    private string connectionString()
 14    ...{
 15        SmallBusinessDataProvidersSection sec = (ConfigurationManager.GetSection("SmallBusinessDataProviders")) as SmallBusinessDataProvidersSection;
 16        string connectionStringName = sec.CatalogProviders[sec.CatalogProviderName].Parameters["connectionStringName"];
 17        return WebConfigurationManager.ConnectionStrings[connectionStringName].ConnectionString;
 18    }
 19    /**////<summary>
 20    /// 返回属于指定分类ID的产品列表。如果产品中没有价格，则Double.MinValue被返回。
 21    /// </summary>
 22    public override List<Item> GetChildItems(string parentCategoryId)
 23    ...{
 24        List<Item> list = new List<Item>();
 25        //参数检验
 26        if (String.IsNullOrEmpty(parentCategoryId)) return list;
 27        // 连接到数据源
 28        using (SqlConnection con = new SqlConnection(connectionString()))
 29        ...{ 
 30            con.Open();
 31            //使用存储过程GetChildItems获取产品列表
 32            SqlCommand cmd = new SqlCommand("GetChildItems", con);
 33            cmd.CommandType = CommandType.StoredProcedure;
 34            //初始化参数
 35            cmd.Parameters.Add("@categoryId", SqlDbType.NVarChar);            
 36            cmd.Parameters["@categoryId"].Value = parentCategoryId;
 37            //执行存储过程返回SqldataReader.
 38            SqlDataReader r = cmd.ExecuteReader();
 39            Item curr;
 40            //遍历SqlDataRader对象，用数据初始化Item实体类，并添加到List<Item>泛型集合。
 41            while (r.Read())
 42            ...{
 43                if (r["id"] is DBNull || r["visible"] is DBNull || r["title"] is DBNull)
 44                    throw new InvalidOperationException(Messages.ItemRequiredAttributesMissing);
 45
 46                curr = new Item((string) r["id"],
 47                                (Boolean)r["visible"],
 48                                (string) r["title"]);
 49                curr.Description = (r["description"] is DBNull) ? String.Empty : (string)r["description"];
 50                curr.Price = (r["price"] is DBNull) ? Double.MinValue : (double)r["price"];
 51                curr.InStock = (r["inStock"] is DBNull) ? true : (Boolean)r["inStock"];
 52                curr.ImageUrl = (r["imageUrl"] is DBNull) ? String.Empty : (string)r["imageUrl"];
 53                curr.ImageAltText = (r["imageAltText"] is DBNull) ? String.Empty : (string)r["imageAltText"];
 54                list.Add(curr);
 55            }
 56        }
 57        //返回列表
 58        return list;
 59    }
 60    /**////<summary>
 61    ///返回指定分类下面的子分类。
 62    ///</summary>
 63    public override List<Category> GetChildCategories(string parentCategoryId)
 64    ...{   
 65        List<Category> list       = new List<Category>();        
 66        using (SqlConnection con = new SqlConnection(connectionString()))
 67        ...{
 68            con.Open();
 69            SqlCommand cmd;
 70            if( String.IsNullOrEmpty(parentCategoryId))
 71            ...{
 72                //使用GetRootCategories方法获取子分类数据。
 73                cmd = new SqlCommand("GetRootCategories", con);
 74            }
 75            else
 76            ...{
 77                //如果没有指定分类ID，则使用GetNonRootCategories存储过程获取分类数据。
 78                cmd = new SqlCommand("GetNonRootCategories ", con);
 79                cmd.CommandType = CommandType.StoredProcedure;
 80                cmd.Parameters.Add("@categoryId", SqlDbType.NVarChar);
 81                cmd.Parameters["@categoryId"].Value = parentCategoryId;
 82            }
 83            //返回SqldataReader
 84            SqlDataReader r = cmd.ExecuteReader();
 85            Category curr;
 86            //遍历SqlDataReader对象，将其中的数据赋给Category实体对象，并将Category实体对象添加到List<Catagory>中。
 87            while (r.Read())
 88            ...{
 89                if (r["id"] is DBNull || r["visible"] is DBNull || r["title"] is DBNull)
 90                    throw new InvalidOperationException(Messages.CategoryRequiredAttributesMissing);
 91
 92                curr = new Category((string)r["id"],(Boolean)r["visible"],(string)r["title"]);
 93                curr.Description = (r["description"] is DBNull) ? String.Empty : (string)r["description"];
 94                curr.ImageUrl = (r["imageUrl"] is DBNull) ? String.Empty : (string)r["imageUrl"];
 95                curr.ImageAltText = (r["imageAltText"] is DBNull) ? String.Empty : (string)r["imageAltText"];
 96                list.Add(curr);
 97            }
 98        }
 99        return list;
100    }
101    /**////<summary>
102    ///根据指定的ItemID返回产品
103    ///</summary>
104    public override Item GetItem(string itemId)
105    ...{
106        //检查参数
107        if (String.IsNullOrEmpty(itemId)) return null;
108        // 连接到数据库
109        Item curr;
110        using (SqlConnection con = new SqlConnection(connectionString()))
111        ...{
112            con.Open();
113            SqlCommand cmd = new SqlCommand("GetItem", con);
114            cmd.CommandType = CommandType.StoredProcedure;
115            cmd.Parameters.Add("@itemId", SqlDbType.NVarChar);
116            cmd.Parameters["@itemId"].Value = itemId;
117            //调用GetItem存储过程，返回SqlDataReader对象。
118            SqlDataReader r = cmd.ExecuteReader();
119            r.Read();
120            //遍历SqlDataReader对象，返回一个被赋值的Item实体对象。
121            if (r["id"] is DBNull || r["visible"] is DBNull || r["title"] is DBNull)
122                throw new InvalidOperationException(Messages.ItemRequiredAttributesMissing);
123
124            curr = new Item((string)r["id"],
125                            (Boolean)r["visible"],
126                            (string)r["title"]);
127            curr.Description = (r["description"] is DBNull) ? String.Empty : (string)r["description"];
128            curr.Price = (r["price"] is DBNull) ? Double.MinValue : (double)r["price"];
129            curr.InStock = (r["inStock"] is DBNull) ? true : (Boolean)r["inStock"];
130            curr.ImageUrl = (r["imageUrl"] is DBNull) ? String.Empty : (string)r["imageUrl"];
131            curr.ImageAltText = (r["imageAltText"] is DBNull) ? String.Empty : (string)r["imageAltText"];
132        }
133        return curr;    
134    }
135} 
136