6.4 ASP.NET 2.0新特性
由于PetShop 4.0是基于.NET Framework 2.0平台开发的电子商务系统，因而它在表示层也引入了许多ASP.NET 2.0的新特性，例如MemberShip、Profile、Master Page、登录控件等特性。接下来，我将结合PetShop 4.0的设计分别介绍它们的实现。
6.4.1 Profile特性
Profile提供的功能是针对用户的个性化服务。在ASP.NET 1.x版本时，我们可以利用Session、Cookie等方法来存储用户的状态信息。然而Session对象是具有生存期的，一旦生存期结束，该对象保留的值就会失效。Cookie将用户信息保存在客户端，它具有一定的安全隐患，一些重要的信息不能存储在Cookie中。一旦客户端禁止使用Cookie，则该功能就将失去应用的作用。
Profile的出现解决了如上的烦恼，它可以将用户的个人化信息保存在指定的数据库中。ASP.NET 2.0的Profile功能默认支持Access数据库和SQL Server数据库，如果需要支持其他数据库，可以编写相关的ProfileProvider类。Profile对象是强类型的，我们可以为用户信息建立属性，以PetShop 4.0为例，它建立了ShoppingCart、WishList和AccountInfo属性。
由于Profile功能需要访问数据库，因而在数据访问层（DAL）定义了和Product等数据表相似的模块结构。首先定义了一个IProfileDAL接口模块，包含了接口IPetShopProfileProvider：
public interface IPetShopProfileProvider { AddressInfo GetAccountInfo(string userName, string appName); void SetAccountInfo(int uniqueID, AddressInfo addressInfo); IList<CartItemInfo> GetCartItems(string userName, string appName, bool isShoppingCart); void SetCartItems(int uniqueID, ICollection<CartItemInfo> cartItems, bool isShoppingCart); void UpdateActivityDates(string userName, bool activityOnly, string appName); int GetUniqueID(string userName, bool isAuthenticated, bool ignoreAuthenticationType, string appName); int CreateProfileForUser(string userName, bool isAuthenticated, string appName); IList<string> GetInactiveProfiles(int authenticationOption, DateTime userInactiveSinceDate, string appName); bool DeleteProfile(string userName, string appName); IList<CustomProfileInfo> GetProfileInfo(int authenticationOption, string usernameToMatch, DateTime userInactiveSinceDate, string appName, out int totalRecords);}因为PetShop 4.0版本分别支持SQL Server和Oracle数据库，因而它分别定义了两个不同的PetShopProfileProvider类，实现IPetShopProfileProvider接口，并放在两个不同的模块SQLProfileDAL和OracleProfileDAL中。具体的实现请参见PetShop 4.0的源代码。同样的，PetShop 4.0为Profile引入了工厂模式，定义了模块ProfileDALFActory，工厂类DataAccess的定义如下：
public sealed class DataAccess { private static readonly string profilePath = ConfigurationManager.AppSettings["ProfileDAL"]; public static PetShop.IProfileDAL.IPetShopProfileProvider CreatePetShopProfileProvider() { string className = profilePath + ".PetShopProfileProvider"; return (PetShop.IProfileDAL.IPetShopProfileProvider)Assembly.Load(profilePath).CreateInstance(className); }}在业务逻辑层（BLL）中，单独定义了模块Profile，它添加了对BLL、IProfileDAL和ProfileDALFactory模块的程序集。在该模块中，定义了密封类PetShopProfileProvider，它继承自System.Web.Profile.ProfileProvider类，该类作为Profile的Provider基类，用于在自定义配置文件中实现相关的配置文件服务。在PetShopProfileProvider类中，重写了父类ProfileProvider中的一些方法，例如Initialize()、GetPropertyValues()、SetPropertyValues()、DeleteProfiles()等方法。此外，还为ShoppingCart、WishList、AccountInfo属性提供了Get和Set方法。至于Provider的具体实现，则调用工厂类DataAccess创建的具体类型对象，如下所示：private static readonly IPetShopProfileProvider dal = DataAccess.CreatePetShopProfileProvider();
定义了PetShop.Profile.PetShopProfileProvider类后，才可以在web.config配置文件中配置如下的配置节：
< profile automaticSaveEnabled = " false " defaultProvider = " ShoppingCartProvider " > < providers > < add name = " ShoppingCartProvider " connectionStringName = " SQLProfileConnString " type = " PetShop.Profile.PetShopProfileProvider " applicationName = " .NET Pet Shop 4.0 " /> < add name = " WishListProvider " connectionStringName = " SQLProfileConnString " type = " PetShop.Profile.PetShopProfileProvider " applicationName = " .NET Pet Shop 4.0 " /> < add name = " AccountInfoProvider " connectionStringName = " SQLProfileConnString " type = " PetShop.Profile.PetShopProfileProvider " applicationName = " .NET Pet Shop 4.0 " /> </ providers > < properties > < add name = " ShoppingCart " type = " PetShop.BLL.Cart " allowAnonymous = " true " provider = " ShoppingCartProvider " /> < add name = " WishList " type = " PetShop.BLL.Cart " allowAnonymous = " true " provider = " WishListProvider " /> < add name = " AccountInfo " type = " PetShop.Model.AddressInfo " allowAnonymous = " false " provider = " AccountInfoProvider " /> </ properties > </ profile >在配置文件中，针对ShoppingCart、WishList和AccountInfo（它们的类型分别为PetShop.BLL.Cart、PetShop.BLL.Cart、PetShop.Model.AddressInfo）属性分别定义了ShoppingCartProvider、WishListProvider、AccountInfoProvider，它们的类型均为PetShop.Profile.PetShopProfileProvider类型。至于Profile的信息究竟是存储在何种类型的数据库中，则由以下的配置节决定：<add key="ProfileDAL" value="PetShop.SQLProfileDAL"/>
而键值为ProfileDAL的值，正是Profile的工厂类PetShop.ProfileDALFactory.DataAccess在利用反射技术创建IPetShopProfileProvider类型对象时获取的。
在表示层中，可以利用页面的Profile属性访问用户的个性化属性，例如在ShoppingCart页面的codebehind代码ShoppingCart.aspx.cs中，调用Profile的ShoppingCart属性：
public partial class ShoppingCart : System.Web.UI.Page { protected void Page_PreInit(object sender, EventArgs e) { if (!IsPostBack) { string itemId = Request.QueryString["addItem"]; if (!string.IsNullOrEmpty(itemId)) { Profile.ShoppingCart.Add(itemId); Profile.Save(); // Redirect to prevent duplictations in the cart if user hits "Refresh" Response.Redirect("~/ShoppingCart.aspx", true); } } }}在上述的代码中，Profile属性的值从何而来？实际上，在我们为web.config配置文件中对Profile进行配置后，启动Web应用程序，ASP.NET会根据该配置文件中的相关配置创建一个ProfileCommon类的实例。该类继承自System.Web.Profile.ProfileBase类。然后调用从父类继承来的GetPropertyValue和SetPropertyValue方法，检索和设置配置文件的属性值。然后，ASP.NET将创建好的ProfileCommon实例设置为页面的Profile属性值。因而，我们可以通过智能感知获取Profile的ShoppingCart属性，同时也可以利用ProfileCommon继承自ProfileBase类的Save()方法，根据属性值更新Profile的数据源。
6.4.2 Membership特性
PetShop 4.0并没有利用Membership的高级功能，而是直接让Membership特性和ASP.NET 2.0新增的登录控件进行绑定。由于.NET Framework 2.0已经定义了针对SQL Server的SqlMembershipProvider，因此对于PetShop 4.0而言，实现Membership比之实现Profile要简单，仅仅需要为Oracle数据库定义MembershipProvider即可。在PetShop.Membership模块中，定义了OracleMembershipProvider类，它继承自System.Web.Security.MembershipProvider抽象类。
OracleMembershipProvider类的实现具有极高的参考价值，如果我们需要定义自己的MembershipProvider类，可以参考该类的实现。事实上OracleMemberShip类的实现并不复杂，在该类中，主要是针对用户及用户安全而实现相关的行为。由于在父类MembershipProvider中，已经定义了相关操作的虚方法，因此我们需要作的是重写这些虚方法。由于与Membership有关的信息都是存储在数据库中，因而OracleMembershipProvider与SqlMembershipProvider类的主要区别还是在于对数据库的访问。对于SQL Server而言，我们利用aspnet_regsql工具为Membership建立了相关的数据表以及存储过程。也许是因为知识产权的原因，Microsoft并没有为Oracle数据库提供类似的工具，因而需要我们自己去创建membership的数据表。此外，由于没有创建Oracle数据库的存储过程，因而OracleMembershipProvider类中的实现是直接调用SQL语句。以CreateUser()方法为例，剔除那些繁杂的参数判断与安全性判断，SqlMembershipProvider类的实现如下：
public override MembershipUser CreateUser( string username, string password, string email, string passwordQuestion, string passwordAnswer, bool isApproved, object providerUserKey, out MembershipCreateStatus status) { MembershipUser user1; //前面的代码略; try { SqlConnectionHolder holder1 = null; try { holder1 = SqlConnectionHelper.GetConnection(this._sqlConnectionString, true); this.CheckSchemaVersion(holder1.Connection); DateTime time1 = this.RoundToSeconds(DateTime.UtcNow); SqlCommand command1 = new SqlCommand("dbo.aspnet_Membership_CreateUser", holder1.Connection); command1.CommandTimeout = this.CommandTimeout; command1.CommandType = CommandType.StoredProcedure; command1.Parameters.Add(this.CreateInputParam("@ApplicationName", SqlDbType.NVarChar, this.ApplicationName)); command1.Parameters.Add(this.CreateInputParam("@UserName", SqlDbType.NVarChar, username)); command1.Parameters.Add(this.CreateInputParam("@Password", SqlDbType.NVarChar, text2)); command1.Parameters.Add(this.CreateInputParam("@PasswordSalt", SqlDbType.NVarChar, text1)); command1.Parameters.Add(this.CreateInputParam("@Email", SqlDbType.NVarChar, email)); command1.Parameters.Add(this.CreateInputParam("@PasswordQuestion", SqlDbType.NVarChar, passwordQuestion)); command1.Parameters.Add(this.CreateInputParam("@PasswordAnswer", SqlDbType.NVarChar, text3)); command1.Parameters.Add(this.CreateInputParam("@IsApproved", SqlDbType.Bit, isApproved)); command1.Parameters.Add(this.CreateInputParam("@UniqueEmail", SqlDbType.Int, this.RequiresUniqueEmail ? 1 : 0)); command1.Parameters.Add(this.CreateInputParam("@PasswordFormat", SqlDbType.Int, (int) this.PasswordFormat)); command1.Parameters.Add(this.CreateInputParam("@CurrentTimeUtc", SqlDbType.DateTime, time1)); SqlParameter parameter1 = this.CreateInputParam("@UserId", SqlDbType.UniqueIdentifier, providerUserKey); parameter1.Direction = ParameterDirection.InputOutput; command1.Parameters.Add(parameter1); parameter1 = new SqlParameter("@ReturnValue", SqlDbType.Int); parameter1.Direction = ParameterDirection.ReturnValue; command1.Parameters.Add(parameter1); command1.ExecuteNonQuery(); int num3 = (parameter1.Value != null) ? ((int) parameter1.Value) : -1; if ((num3 < 0) || (num3 > 11)) { num3 = 11; } status = (MembershipCreateStatus) num3; if (num3 != 0) { return null; } providerUserKey = new Guid(command1.Parameters["@UserId"].Value.ToString()); time1 = time1.ToLocalTime(); user1 = new MembershipUser(this.Name, username, providerUserKey, email, passwordQuestion, null, isApproved, false, time1, time1, time1, time1, new DateTime(0x6da, 1, 1)); } finally { if (holder1 != null) { holder1.Close(); holder1 = null; } } } catch { throw; } return user1;}代码中，aspnet_Membership_CreateUser为aspnet_regsql工具为membership创建的存储过程，它的功能就是创建一个用户。
OracleMembershipProvider类中对CreateUser()方法的定义如下：
public override MembershipUser CreateUser( string username, string password, string email, string passwordQuestion, string passwordAnswer, bool isApproved, object userId, out MembershipCreateStatus status) { //前面的代码略; //Create connection OracleConnection connection = new OracleConnection(OracleHelper.ConnectionStringMembership); connection.Open(); OracleTransaction transaction = connection.BeginTransaction(IsolationLevel.ReadCommitted); try { DateTime dt = DateTime.Now; bool isUserNew = true; // Step 1: Check if the user exists in the Users table: create if not int uid = GetUserID(transaction, applicationId, username, true, false, dt, out isUserNew); if(uid == 0) { // User not created successfully! status = MembershipCreateStatus.ProviderError; return null; } // Step 2: Check if the user exists in the Membership table: Error if yes. if(IsUserInMembership(transaction, uid)) { status = MembershipCreateStatus.DuplicateUserName; return null; } // Step 3: Check if Email is duplicate if(IsEmailInMembership(transaction, email, applicationId)) { status = MembershipCreateStatus.DuplicateEmail; return null; } // Step 4: Create user in Membership table int pFormat = (int)passwordFormat; if(!InsertUser(transaction, uid, email, pass, pFormat, salt, "", "", isApproved, dt)) { status = MembershipCreateStatus.ProviderError; return null; } // Step 5: Update activity date if user is not new if(!isUserNew) { if(!UpdateLastActivityDate(transaction, uid, dt)) { status = MembershipCreateStatus.ProviderError; return null; } } status = MembershipCreateStatus.Success; return new MembershipUser(this.Name, username, uid, email, passwordQuestion, null, isApproved, false, dt, dt, dt, dt, DateTime.MinValue); } catch(Exception) { if(status == MembershipCreateStatus.Success) status = MembershipCreateStatus.ProviderError; throw; } finally { if(status == MembershipCreateStatus.Success) transaction.Commit(); else transaction.Rollback(); connection.Close(); connection.Dispose(); }} <script type="text/javascript"> </script><script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"> </script>