對于Microsoft .net PetShop程序中的購物車和訂單處理模塊，文中主要分析兩種技術(shù)的應(yīng)用：

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1. Profile技術(shù)在PetShop程序中用于三處：

??? 1) 購物車ShoppingCart ???－下面的例子圍繞購物車流程進(jìn)行

??? 2) 收藏WishList

??? 3)?用戶信息AccountInfo

??注冊新用戶 NewUser.aspx ：使用的是CreateUserWizard 控件，基于MemberShip機(jī)制，在數(shù)據(jù)庫MSPetShop4Services的表aspnet_Users中創(chuàng)建用戶

??修改用戶注冊信息 UserProfile.aspx： 基于Profile技術(shù)，在數(shù)據(jù)庫MSPetShop4Profile的表Profiles和Account中創(chuàng)建用戶信息

2. 異步消息處理技術(shù)運(yùn)用于訂單處理

4.1 Web.config配置

Profile可以利用數(shù)據(jù)庫存儲關(guān)于用戶的個性化信息，有點(diǎn)象session對象，但session對象是有生存期的，在生存期后，session對象自動失效了。而profile不同，除非顯式移除它。要實(shí)現(xiàn)profile功能，必須先在web.config中進(jìn)行定義。

在web.congfig中，將會定義一些屬性/值，分別存貯將要保存的變量和值，比如language屬性，定義其值是string類型，如此類推。而＜group＞標(biāo)簽，則是將一些相同或類似功能的變量值放在一起。

程序中使用方法：Profile.language = ddlLanguage.SelectedItem.Value;

<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>

4.2 購物車程序流程－Profile技術(shù)

1.?????? 點(diǎn)擊“加入購物車”： http://localhost:2327/Web/ShoppingCart.aspx?addItem=EST-34

2.???? ShoppingCart.aspx文件處理：在init方法之前處理

????? protected void Page_PreInit(object sender, EventArgs e) {

??????? if (!IsPostBack) {

??????????? string itemId = Request.QueryString["addItem"];

??????????? if (!string.IsNullOrEmpty(itemId)) {

??????????????? Profile.ShoppingCart.Add(itemId); //注意ShoppingCart的類型是PetShop.BLL.Cart

??????????????? //Save 方法將修改后的配置文件屬性值寫入到數(shù)據(jù)源，如ShoppingCart屬性已經(jīng)改變

??????????????? Profile.Save();???

?????????

??????????????? // Redirect to prevent duplictations in the cart if user hits "Refresh"

??????????????? //防止刷新造成 多次提交

??????????????? Response.Redirect("~/ShoppingCart.aspx", true);?//將客戶端重定向到新的 URL。指定新的 URL 并指定當(dāng)前頁的執(zhí)行是否應(yīng)終止。

??????????? }

??????? }

3.???? PetShop.BLL.Cart類

// Dictionary: key/value?

private Dictionary<string, CartItemInfo> cartItems = new Dictionary<string, CartItemInfo>();

/// <summary>

??????? /// Add an item to the cart.

??????? /// When ItemId to be added has already existed, this method will update the quantity instead.

??????? /// </summary>

??????? /// <param name="itemId">Item Id of item to add</param>

??????? public void Add(string itemId) {

CartItemInfo cartItem;

//獲取與指定的鍵相關(guān)聯(lián)的值TryGetValue(TKey key,out TValue value)

??????????? if (!cartItems.TryGetValue(itemId, out cartItem)) {

??????????????? Item item = new Item();

??????????????? ItemInfo data = item.GetItem(itemId);

??????????????? if (data != null) {

?????????? ?????????CartItemInfo newItem = new CartItemInfo(itemId, data.ProductName, 1, (decimal)data.Price, data.Name, data.CategoryId, data.ProductId);

??????????????????? cartItems.Add(itemId, newItem);

??????????????? }

??????????? }

??????????? else

?????????? ?????cartItem.Quantity++;

??????? }

4.???? 更新Profile

//Save 方法將修改后的配置文件屬性值寫入到數(shù)據(jù)源，如ShoppingCart屬性已經(jīng)改變

??????????????? Profile.Save();?

如何更新:

??? 根據(jù)配置中的ShoppingCartProvider類型 PetShop.Profile.PetShopProfileProvider。

?

ASP.NET 配置文件提供對用戶特定屬性的持久性存儲和檢索。配置文件屬性值和信息按照由 ProfileProvider 實(shí)現(xiàn)確定的方式存儲在數(shù)據(jù)源中。

每個用戶配置文件在數(shù)據(jù)庫的 Profiles 表中進(jìn)行唯一標(biāo)識。該表包含配置文件信息，如應(yīng)用程序名稱和上次活動日期。

CREATE TABLE Profiles ( ?UniqueID AutoIncrement NOT NULL PRIMARY KEY, ?Username Text (255) NOT NULL, ?ApplicationName Text (255) NOT NULL, ?IsAnonymous YesNo, ??LastActivityDate DateTime, ?LastUpdatedDate DateTime, ?CONSTRAINT PKProfiles UNIQUE (Username, ApplicationName) )

5.???? PetShop.Profile. PetShopProfileProvider類， 繼承自ProfileProvider

// 創(chuàng)建 PetShop.SQLProfileDAL.PetShopProfileProvider類-數(shù)據(jù)庫操作

???????? private static readonly IPetShopProfileProvider dal

= DataAccess.CreatePetShopProfileProvider();

?

/// <summary>

??????? /// 設(shè)置指定的屬性設(shè)置組的值

??????? /// </summary>

???????? public override void SetPropertyValues(SettingsContext context, SettingsPropertyValueCollection collection) {

????????????? string username = (string)context["UserName"];

????????????? CheckUserName(username);?????????????????????? ?

????????????? bool isAuthenticated = (bool)context["IsAuthenticated"];

????????????? int uniqueID = dal.GetUniqueID(username, isAuthenticated, false, ApplicationName);

????????????? if(uniqueID == 0)

?????????????????? uniqueID = dal.CreateProfileForUser(username, isAuthenticated, ApplicationName);

????????????? foreach(SettingsPropertyValue pv in collection) {

?????????????????? if(pv.PropertyValue != null) {

?????????????????????? switch(pv.Property.Name) {

??????????????????????????? case PROFILE_SHOPPINGCART:?? //ShoppingCart

???????????????????????????????? SetCartItems(uniqueID, (Cart)pv.PropertyValue, true);

???????????????????????????????? break;

??????????????????????????? case PROFILE_WISHLIST:

???????????????????????????????? SetCartItems(uniqueID, (Cart)pv.PropertyValue, false);

???????????????????????????????? break;

??????????????????????????? case PROFILE_ACCOUNT:

???????????????????????????????? if(isAuthenticated)

???????????????????????????????????? SetAccountInfo(uniqueID, (AddressInfo)pv.PropertyValue);

???????????????????????????????? break;

??????????????????????????? default:

???????????????????????????????? throw new ApplicationException(ERR_INVALID_PARAMETER + " name.");

?????????????????????? }

?????????????????? }

????????????? }

????????????? UpdateActivityDates(username, false);

???????? }

?

// Update cart

???????? private static void SetCartItems(int uniqueID, Cart cart, bool isShoppingCart) {

????????????? dal.SetCartItems(uniqueID, cart.CartItems, isShoppingCart);

???????? }

6.?????? PetShop.SQLProfileDAL. PetShopProfileProvider類

使用事務(wù)：包含兩個sql動作，先刪除，再插入

/// <summary>

??????? /// Update shopping cart for current user

??????? /// </summary>

??????? /// <param name="uniqueID">User id</param>

??????? /// <param name="cartItems">Collection of shopping cart items</param>

??????? /// <param name="isShoppingCart">Shopping cart flag</param>

???????? public void SetCartItems(int uniqueID, ICollection<CartItemInfo> cartItems, bool isShoppingCart) {

?????????????????? string sqlDelete = "DELETE FROM Cart WHERE UniqueID = @UniqueID AND IsShoppingCart = @IsShoppingCart;";

????????????? SqlParameter[] parms1 = {???????????????? ??

?????????????????? new SqlParameter("@UniqueID", SqlDbType.Int),

?????????????????? new SqlParameter("@IsShoppingCart", SqlDbType.Bit)};

????????????? parms1[0].Value = uniqueID;

????????????? parms1[1].Value = isShoppingCart;

??????????? if (cartItems.Count > 0) {

??????????????? // update cart using SqlTransaction

??????????????? string sqlInsert = "INSERT INTO Cart (UniqueID, ItemId, Name, Type, Price, CategoryId, ProductId, IsShoppingCart, Quantity) VALUES (@UniqueID, @ItemId, @Name, @Type, @Price, @CategoryId, @ProductId, @IsShoppingCart, @Quantity);";

??????????????? SqlParameter[] parms2 = {?????????????? ??

?????????????????? new SqlParameter("@UniqueID", SqlDbType.Int),?

?????????????????? new SqlParameter("@IsShoppingCart", SqlDbType.Bit),

?????????????????? new SqlParameter("@ItemId", SqlDbType.VarChar, 10),

?????????????????? new SqlParameter("@Name", SqlDbType.VarChar, 80),

?????????????????? new SqlParameter("@Type", SqlDbType.VarChar, 80),

?????????????????? new SqlParameter("@Price", SqlDbType.Decimal, 8),

?????????????????? new SqlParameter("@CategoryId", SqlDbType.VarChar, 10),

?????????????????? new SqlParameter("@ProductId", SqlDbType.VarChar, 10),

?????????????????? new SqlParameter("@Quantity", SqlDbType.Int)};

??????????????? parms2[0].Value = uniqueID;

?????????? ?????parms2[1].Value = isShoppingCart;

??????????????? SqlConnection conn = new SqlConnection(SqlHelper.ConnectionStringProfile);

??????????????? conn.Open();

??????????????? SqlTransaction trans = conn.BeginTransaction(IsolationLevel.ReadCommitted);

?? ?????????????try {

??????????????????? SqlHelper.ExecuteNonQuery(trans, CommandType.Text, sqlDelete, parms1);

??????????????????? foreach (CartItemInfo cartItem in cartItems) {

??????????????????????? parms2[2].Value = cartItem.ItemId;

?????????????????? ?????parms2[3].Value = cartItem.Name;

??????????????????????? parms2[4].Value = cartItem.Type;

??????????????????????? parms2[5].Value = cartItem.Price;

??????????????????????? parms2[6].Value = cartItem.CategoryId;

??????????????????????? parms2[7].Value = cartItem.ProductId;

??????????????????????? parms2[8].Value = cartItem.Quantity;

??????????????????????? SqlHelper.ExecuteNonQuery(trans, CommandType.Text, sqlInsert, parms2);

??????????????????? }

??????????????????? trans.Commit();

??????????????? }

???????????????catch (Exception e) {

??????????????????? trans.Rollback();

??????????????????? throw new ApplicationException(e.Message);

??????????????? }

??????????????? finally {

??????????????????? conn.Close();

??????????????? }

??????????? }

???????? ???else

??????????????? // delete cart

??????????????? SqlHelper.ExecuteNonQuery(SqlHelper.ConnectionStringProfile, CommandType.Text, sqlDelete, parms1);

???????? }

4.3 訂單處理技術(shù)

訂單處理技術(shù)：――分布式事務(wù)

1）?同步：直接在事務(wù)中 將訂單 插入到數(shù)據(jù)庫中，同時(shí)更新庫存

2）?異步：訂單－》消息隊(duì)列(使用MSMQ)－》后臺處理?

4.3.1 使用Wizard組件

4.3.2 分布式事務(wù)處理技術(shù)

開啟MSDTC 服務(wù)支持分布式事務(wù). To start the MSDTC service, open Administrative Tools | Services and start the Distributed Transaction Coordinator service

4.3.3 MSMQ 消息隊(duì)列簡介

1）引用隊(duì)列

????? 引用隊(duì)列有三種方法，通過路徑、格式名和標(biāo)簽引用隊(duì)列，這里我只介紹最簡單和最常用的方法：通過路徑引用隊(duì)列。隊(duì)列路徑的形式為 machinename\queuename。指向隊(duì)列的路徑總是唯一的。下表列出用于每種類型的隊(duì)列的路徑信息：

如果是發(fā)送到本機(jī)上，還可以使用”.”代表本機(jī)名稱。

2）消息的創(chuàng)建

不過要使用MSMQ開發(fā)你的消息處理程序，必須在開發(fā)系統(tǒng)和使用程序的主機(jī)上安裝消息隊(duì)列。消息隊(duì)列的安裝屬于Windows組件的安裝，和一般的組件安裝方法類似。

往系統(tǒng)中添加隊(duì)列十分的簡單，打開[控制面板]中的[計(jì)算機(jī)管理]，展開[服務(wù)和應(yīng)用程序]，找到并展開[消息隊(duì)列]（如果找不到，說明你還沒有安裝消息隊(duì)列，安裝windows組件），右擊希望添加的消息隊(duì)列的類別，選擇新建隊(duì)列即可。

消息接收服務(wù)位于System.Messaging中，在初始化時(shí)引用消息隊(duì)列的代碼很簡單，如下所示：

MessageQueue Mq=new MessageQueue(“.\\private$\\jiang”)；

通過Path屬性引用消息隊(duì)列的代碼也十分簡單：

MessageQueue Mq=new MessageQueue()；

Mq.Path=”.\\private$\\jiang”;

使用Create 方法可以在計(jì)算機(jī)上創(chuàng)建隊(duì)列：

System.Messaging.MessageQueue.Create(@".\private$\jiang");

3) 發(fā)送和接收消息

過程：消息的創(chuàng)建－》發(fā)送－》接收－》閱讀－》關(guān)閉

簡單消息的發(fā)送示例如下：

???????? Mq.Send(1000); //發(fā)送整型數(shù)據(jù)

???????? Mq.Send(“This is a test message!”); //發(fā)送字符串

接收消息由兩種方式：通過Receive方法接收消息同時(shí)永久性地從隊(duì)列中刪除消息；通過Peek方法從隊(duì)列中取出消息而不從隊(duì)列中移除該消息。如果知道消息的標(biāo)識符（ID），還可以通過ReceiveById方法和PeekById方法完成相應(yīng)的操作。

???? 接收消息的代碼很簡單：

???????? Mq.Receive(); //或Mq.ReceiveById(ID);

???????? Mq.Peek();?// 或Mq.PeekById(ID);

閱讀消息

接收到的消息只有能夠讀出來才是有用的消息，因此接收到消息以后還必須能讀出消息，而讀出消息算是最復(fù)雜的一部操作了。消息的序列化可以通過Visual Studio 和 .NET Framework 附帶的三個預(yù)定義的格式化程序來完成：XMLMessageFormatter 對象（ MessageQueue 組件的默認(rèn)格式化程序設(shè)置）、BinaryMessageFormatter 對象、ActiveXMessageFormatter 對象。由于后兩者格式化后的消息通常不能為人閱讀，所以我們經(jīng)常用到的是XMLMessageFormatter對象。

使用XMLMessageFormatter對象格式化消息的代碼如下所示：

?????? string[] types = { "System.String" };

?????? ((XmlMessageFormatter)mq.Formatter).TargetTypeNames = types;

??????? Message m=mq.Receive(new TimeSpan(0,0,3));

?????? 將接收到的消息傳送給消息變量以后，通過消息變量m的Body屬性就可以讀出消息了：

MessageBox.Show((string)m.Body);

關(guān)閉消息隊(duì)列

???? 消息隊(duì)列的關(guān)閉很簡單，和其他對象一樣，通過Close函數(shù)就可以實(shí)現(xiàn)了：

Mq.Close();

4.3.4 PetShop程序中訂單處理－使用同步消息

默認(rèn)程序使用同步消息 處理，直接操作數(shù)據(jù)庫插入訂單，更新庫存類

4.3.5 PetShop程序中訂單處理－使用異步消息

1)??? Web程序中調(diào)用PetShop.BLL.Order類方法：?Insert(OrderInfo order);

2)??? PetShop.BLL.Order類

//IOrderStrategy接口中只有一個插入訂單方法：void Insert(PetShop.Model.OrderInfo order);

??????? //得到PetShop.BLL. OrderAsynchronous類

??????? private static readonly PetShop.IBLLStrategy.IOrderStrategy orderInsertStrategy = LoadInsertStrategy();

???? ???//IOrder接口中有兩種方法：Send()與Receive()?－消息隊(duì)列

??????? private static readonly PetShop.IMessaging.IOrder orderQueue

= PetShop.MessagingFactory.QueueAccess.CreateOrder();

?

public void Insert(OrderInfo order) {

??????????? // Call credit card procesor，采用隨機(jī)化方法設(shè)置訂單認(rèn)證數(shù)字

??????????? ProcessCreditCard(order);

??????????? // Insert the order (a)synchrounously based on configuration

??????????? orderInsertStrategy.Insert(order);??? //調(diào)用PetShop.BLL.OrderAsynchronous類

??????? }

3)??? PetShop.BLL. OrderAsynchronous類

?

// CreateOrder()方法得到PetShop.MSMQMessaging .Order類的實(shí)例

private static readonly PetShop.IMessaging.IOrder asynchOrder

?= PetShop.MessagingFactory.QueueAccess.CreateOrder();

public void Insert(PetShop.Model.OrderInfo order) {

??????????? asynchOrder.Send(order);??? //調(diào)用PetShop.MSMQMessaging.Order類

??????? }

4)??? PetShop.MSMQMessaging項(xiàng)目 －關(guān)鍵（發(fā)送/接收消息）

PetShopQueue基類：創(chuàng)建消息隊(duì)列，發(fā)送和接收消息

Order類：繼承自PetShopQueue類

public new OrderInfo Receive() {??????????? //從隊(duì)列中接收消息

??????????? base.transactionType = MessageQueueTransactionType.Automatic;

??????????? return (OrderInfo)((Message)base.Receive()).Body;

??????? }

public void Send(OrderInfo orderMessage) {?//發(fā)送消息到隊(duì)列

??????????? base.transactionType = MessageQueueTransactionType.Single;

??????????? base.Send(orderMessage);

??????? }

5)??? PetShop.OrderProcessor項(xiàng)目－后臺處理訂單，將它們插入到數(shù)據(jù)庫中

Program類：多線程后臺訂單處理程序，可寫成一個控制臺程序，作為windows服務(wù)開啟

處理隊(duì)列中的批量異步訂單，在事務(wù)范圍內(nèi)把它們提交到數(shù)據(jù)庫

轉(zhuǎn)載于:https://www.cnblogs.com/hnsjack/articles/608501.html

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