精进不休 .NET 4.0 (8) ADO.NET Entity Framework 4.0 Self Tracking Entity

精进不休 .NET 4.0 (8) ADO.NET Entity Framework 4.0 Self Tracking Entity
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精进不休 .NET 4.0 (8) - ADO.NET Entity Framework 4.0 Self Tracking Entity

作者：webabcd

介绍
ADO.NET Entity Framework 4.0 的新增功能
- 对 Self Tracking Entity（实体状态自跟踪）的支持，基于 POCO
- WCF 结合 Self Tracking Entity 的应用
示例
1、Self Tracking Entity 的 Demo
SelfTrackingDemo/BLL.cs

代码

/*
* ADO.NET Entity Framework 4.0 - 对 Self Tracking Entity（实体状态自跟踪）的支持，基于 POCO
*     1、不通过 WCF 使用 Self Tracking Entity 需要手动调用 StartTracking()
*     2、MarkAsAdded(), MarkAsModified(), MarkAsDeleted() 会自动 StartTracking()
*     3、ApplyChanges() 的作用是：绑定实体到上下文，通过 ChangeObjectState 改变实体的状态，通过 ChangeRelationshipState 改变关联实体的状态
*
* 本 Demo 演示如何通过 Self Tracking Entity 来实现对单表的增删改查
*     如果涉及到关联实体，可以参考 http://www.cnblogs.com/webabcd/archive/2010/06/17/1759314.html 中的“对外键的支持”的 Demo
*/

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

namespace SelfTrackingDemo
{
    public class BLL
    {
        // 取全部产品类别的实体集合
        public List<ProductCategory> GetCategories()
        {
            using (SelfTrackingEntities ctx = new SelfTrackingEntities())
            {
                var result = ctx.ProductCategories.ToList();
                return result;
            }
        }

        // 根据 id 取产品类别实体
        public ProductCategory GetCategory(int categoryId)
        {
            using (SelfTrackingEntities ctx = new SelfTrackingEntities())
            {
                var result = ctx.ProductCategories.Single(c => c.ProductCategoryID == categoryId);
                return result;
            }
        }

        // 根据产品类别实体更新数据库中的相关数据
        public void UpdateCategory(ProductCategory category)
        {
            using (SelfTrackingEntities ctx = new SelfTrackingEntities())
            {
                // ApplyChanges() 的内部逻辑为：绑定实体到上下文，通过 ChangeObjectState 改变实体的状态，通过 ChangeRelationshipState 改变关联实体的状态
                ctx.ProductCategories.ApplyChanges(category);

                // 根据实体的状态，实现对实体的添加、更新、删除操作
                var affectedRow = ctx.SaveChanges();
            }
        }

        // 根据产品类别实体删除数据库中的相关数据
        public void DeleteCategory(ProductCategory category)
        {
            // 标记该实体为删除状态
            category.MarkAsDeleted();

            UpdateCategory(category);
        }

        // 根据产品类别实体向数据库添加新的数据
        public void AddCategory(ProductCategory category)
        {
            UpdateCategory(category);
        }
    }
}

SelfTrackingDemo/Demo.aspx
代码

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Demo.aspx.cs" Inherits="SelfTrackingDemo.Demo" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:ListView ID="ListView1" runat="server" DataSourceID="ObjectDataSource1" DataKeyNames="ProductCategoryID"
            InsertItemPosition="LastItem" OnItemUpdating="ListView1_ItemUpdating">
            <EditItemTemplate>
                <tr style="">
                    <td>
                        <asp:Button ID="UpdateButton" runat="server" CommandName="Update" Text="Update" />
                        <asp:Button ID="CancelButton" runat="server" CommandName="Cancel" Text="Cancel" />
                    </td>
                    <td>
                         
                    </td>
                    <td>
                         
                    </td>
                    <td>
                        <asp:TextBox ID="NameTextBox" runat="server" Text='<%# Bind("Name") %>' />
                    </td>
                    <td>
                         
                    </td>
                    <td>
                         
                    </td>
                </tr>
            </EditItemTemplate>
            <InsertItemTemplate>
                <tr style="">
                    <td>
                        <asp:Button ID="InsertButton" runat="server" CommandName="Insert" Text="Insert" />
                        <asp:Button ID="CancelButton" runat="server" CommandName="Cancel" Text="Clear" />
                    </td>
                    <td>
                         
                    </td>
                    <td>
                         
                    </td>
                    <td>
                        <asp:TextBox ID="NameTextBox" runat="server" Text='<%# Bind("Name") %>' />
                    </td>
                    <td>
                         
                    </td>
                    <td>
                         
                    </td>
                </tr>
            </InsertItemTemplate>
            <ItemTemplate>
                <tr style="">
                    <td>
                        <asp:Button ID="DeleteButton" runat="server" CommandName="Delete" Text="Delete" />
                        <asp:Button ID="EditButton" runat="server" CommandName="Edit" Text="Edit" />
                    </td>
                    <td>
                        <asp:Label ID="ProductCategoryIDLabel" runat="server" Text='<%# Eval("ProductCategoryID") %>' />
                    </td>
                    <td>
                        <asp:Label ID="ParentProductCategoryIDLabel" runat="server" Text='<%# Eval("ParentProductCategoryID") %>' />
                    </td>
                    <td>
                        <asp:Label ID="NameLabel" runat="server" Text='<%# Eval("Name") %>' />
                    </td>
                    <td>
                        <asp:Label ID="rowguidLabel" runat="server" Text='<%# Eval("rowguid") %>' />
                    </td>
                    <td>
                        <asp:Label ID="ModifiedDateLabel" runat="server" Text='<%# Eval("ModifiedDate") %>' />
                    </td>
                </tr>
            </ItemTemplate>
            <LayoutTemplate>
                <table id="itemPlaceholderContainer" runat="server" border="0" style="">
                    <tr runat="server" style="">
                        <th runat="server">
                        </th>
                        <th runat="server">
                            ProductCategoryID
                        </th>
                        <th runat="server">
                            ParentProductCategoryID
                        </th>
                        <th runat="server">
                            Name
                        </th>
                        <th runat="server">
                            rowguid
                        </th>
                        <th runat="server">
                            ModifiedDate
                        </th>
                    </tr>
                    <tr id="itemPlaceholder" runat="server">
                    </tr>
                </table>
            </LayoutTemplate>
        </asp:ListView>
        <asp:ObjectDataSource ID="ObjectDataSource1" runat="server" DataObjectTypeName="SelfTrackingDemo.ProductCategory"
            DeleteMethod="DeleteCategory" InsertMethod="AddCategory" SelectMethod="GetCategories"
            TypeName="SelfTrackingDemo.BLL" OnInserting="ObjectDataSource1_Inserting" OnDeleting="ObjectDataSource1_Deleting">
        </asp:ObjectDataSource>
    </div>
    </form>
</body>
</html>

SelfTrackingDemo/Demo.aspx.cs
代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace SelfTrackingDemo
{
    public partial class Demo : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {

        }

        protected void ObjectDataSource1_Inserting(object sender, ObjectDataSourceMethodEventArgs e)
        {
            var category = e.InputParameters[0] as ProductCategory;
            category.rowguid = Guid.NewGuid();
            category.ModifiedDate = DateTime.Now;
        }

        protected void ObjectDataSource1_Deleting(object sender, ObjectDataSourceMethodEventArgs e)
        {

        }

        protected void ListView1_ItemUpdating(object sender, ListViewUpdateEventArgs e)
        {
            BLL bll = new BLL();
            var category = bll.GetCategory((int)ListView1.DataKeys[e.ItemIndex].Value);

            // 注意：这里一定要手动调用 StartTracking() 方法，用于跟踪实体状态的改变
            category.StartTracking();

            category.Name = e.NewValues["Name"].ToString();
            bll.UpdateCategory(category);

            ListView1.EditIndex = -1;
            e.Cancel = true;
        }
    }
}

2、WCF 结合 Self Tracking Entity 的 Demo
服务端：NTierServer/IMyService.cs
代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.Text;

namespace NTierServer
{
    [ServiceContract]
    public interface IMyService
    {
        [OperationContract]
        List<ProductCategory> GetCategories();

        [OperationContract]
        ProductCategory GetCategory(int categoryId);

        [OperationContract]
        int UpdateCategory(ProductCategory category);

        [OperationContract]
        int AddCategory(ProductCategory category);

        [OperationContract]
        int DeleteCategory(int categoryId);
    }
}

服务端：NTierServer/MyService.cs
代码

/*
* ADO.NET Entity Framework 4.0 - WCF 结合 Self Tracking Entity 的应用
*     1、通过 WCF 使用 Self Tracking Entity 不需手动调用 StartTracking()
*     2、先 MarkAsAdded(), MarkAsModified(), MarkAsDeleted() 再 ApplyChanges() ；或者先 ApplyChanges() 再 ChangeObjectState(), ChangeRelationshipState()
*
* 本 Demo 演示如何通过 WCF 结合 Self Tracking Entity 来实现对单表的增删改查
*/

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.Text;
using System.Data;

namespace NTierServer
{
    public class MyService : IMyService
    {
        // 取全部产品类别的实体集合
        public List<ProductCategory> GetCategories()
        {
            using (var ctx = new AdventureWorksEntities())
            {
                var result = ctx.ProductCategories.ToList();
                return result;
            }
        }

        // 根据 id 取产品类别实体
        public ProductCategory GetCategory(int categoryId)
        {
            using (var ctx = new AdventureWorksEntities())
            {
                var result = ctx.ProductCategories.Single(c => c.ProductCategoryID == categoryId);
                return result;
            }
        }

        // 根据产品类别实体更新数据库中的相关数据
        public int UpdateCategory(ProductCategory category)
        {
            using (var ctx = new AdventureWorksEntities())
            {
                // 先 ApplyChanges() 再 ChangeObjectState(), ChangeRelationshipState()
                ctx.ProductCategories.ApplyChanges(category);
                ctx.ObjectStateManager.ChangeObjectState(category, EntityState.Modified);

                return ctx.SaveChanges();
            }
        }

        // 根据产品类别实体向数据库添加新的数据
        public int AddCategory(ProductCategory category)
        {
            using (var ctx = new AdventureWorksEntities())
            {
                ctx.ProductCategories.ApplyChanges(category);
                return ctx.SaveChanges();
            }
        }

        // 根据 id 删除数据库中的相关数据
        public int DeleteCategory(int categoryId)
        {
            using (var ctx = new AdventureWorksEntities())
            {
                var category = GetCategory(categoryId);

                // 先 MarkAsAdded(), MarkAsModified(), MarkAsDeleted() 再 ApplyChanges()
                category.MarkAsDeleted();
                ctx.ProductCategories.ApplyChanges(category);

                return ctx.SaveChanges();
            }
        }
    }
}

服务端：NTierServer/Web.config
代码

<system.serviceModel>
    <behaviors>
        <serviceBehaviors>
            <behavior name="">
                <serviceMetadata httpGetEnabled="true" />
                <serviceDebug includeExceptionDetailInFaults="true" />
            </behavior>
        </serviceBehaviors>
    </behaviors>
    <serviceHostingEnvironment multipleSiteBindingsEnabled="true" />
</system.serviceModel>

客户端：NTierClient/Web.config
代码

<system.serviceModel>
    <bindings>
        <basicHttpBinding>
            <binding name="BasicHttpBinding_IMyService" closeTimeout="00:01:00"
                openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00"
                allowCookies="false" bypassProxyOnLocal="false" hostNameComparisonMode="StrongWildcard"
                maxBufferSize="65536" maxBufferPoolSize="524288" maxReceivedMessageSize="65536"
                messageEncoding="Text" textEncoding="utf-8" transferMode="Buffered"
                useDefaultWebProxy="true">
                <readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384"
                    maxBytesPerRead="4096" maxNameTableCharCount="16384" />
                <security mode="None">
                    <transport clientCredentialType="None" proxyCredentialType="None"
                        realm="" />
                    <message clientCredentialType="UserName" algorithmSuite="Default" />
                </security>
            </binding>
        </basicHttpBinding>
    </bindings>
    <client>
        <endpoint address="http://localhost:10394/MyService.svc" binding="basicHttpBinding"
            bindingConfiguration="BasicHttpBinding_IMyService" contract="MyServiceReference.IMyService"
            name="BasicHttpBinding_IMyService" />
    </client>
</system.serviceModel>

客户端：NTierClient/Demo.aspx
代码

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Demo.aspx.cs" Inherits="NTierClient.Demo" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:ListView ID="ListView1" runat="server" DataKeyNames="ProductCategoryID" InsertItemPosition="LastItem"
            OnItemDeleting="ListView1_ItemDeleting" OnItemInserting="ListView1_ItemInserting"
            OnItemUpdating="ListView1_ItemUpdating" OnItemCanceling="ListView1_ItemCanceling"
            OnItemEditing="ListView1_ItemEditing">
            <EditItemTemplate>
                <tr style="">
                    <td>
                        <asp:Button ID="UpdateButton" runat="server" CommandName="Update" Text="Update" />
                        <asp:Button ID="CancelButton" runat="server" CommandName="Cancel" Text="Cancel" />
                    </td>
                    <td>
                         
                    </td>
                    <td>
                         
                    </td>
                    <td>
                        <asp:TextBox ID="NameTextBox" runat="server" Text='<%# Bind("Name") %>' />
                    </td>
                    <td>
                         
                    </td>
                    <td>
                         
                    </td>
                </tr>
            </EditItemTemplate>
            <InsertItemTemplate>
                <tr style="">
                    <td>
                        <asp:Button ID="InsertButton" runat="server" CommandName="Insert" Text="Insert" />
                        <asp:Button ID="CancelButton" runat="server" CommandName="Cancel" Text="Clear" />
                    </td>
                    <td>
                         
                    </td>
                    <td>
                         
                    </td>
                    <td>
                        <asp:TextBox ID="NameTextBox" runat="server" Text='<%# Bind("Name") %>' />
                    </td>
                    <td>
                         
                    </td>
                    <td>
                         
                    </td>
                </tr>
            </InsertItemTemplate>
            <ItemTemplate>
                <tr style="">
                    <td>
                        <asp:Button ID="DeleteButton" runat="server" CommandName="Delete" Text="Delete" />
                        <asp:Button ID="EditButton" runat="server" CommandName="Edit" Text="Edit" />
                    </td>
                    <td>
                        <asp:Label ID="ProductCategoryIDLabel" runat="server" Text='<%# Eval("ProductCategoryID") %>' />
                    </td>
                    <td>
                        <asp:Label ID="ParentProductCategoryIDLabel" runat="server" Text='<%# Eval("ParentProductCategoryID") %>' />
                    </td>
                    <td>
                        <asp:Label ID="NameLabel" runat="server" Text='<%# Eval("Name") %>' />
                    </td>
                    <td>
                        <asp:Label ID="rowguidLabel" runat="server" Text='<%# Eval("rowguid") %>' />
                    </td>
                    <td>
                        <asp:Label ID="ModifiedDateLabel" runat="server" Text='<%# Eval("ModifiedDate") %>' />
                    </td>
                </tr>
            </ItemTemplate>
            <LayoutTemplate>
                <table id="itemPlaceholderContainer" runat="server" border="0" style="">
                    <tr runat="server" style="">
                        <th runat="server">
                        </th>
                        <th runat="server">
                            ProductCategoryID
                        </th>
                        <th runat="server">
                            ParentProductCategoryID
                        </th>
                        <th runat="server">
                            Name
                        </th>
                        <th runat="server">
                            rowguid
                        </th>
                        <th runat="server">
                            ModifiedDate
                        </th>
                    </tr>
                    <tr id="itemPlaceholder" runat="server">
                    </tr>
                </table>
            </LayoutTemplate>
        </asp:ListView>
    </div>
    </form>
</body>
</html>

客户端：NTierClient/Demo.aspx.cs
代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

using System.ServiceModel;

namespace NTierClient
{
    public partial class Demo : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!Page.IsPostBack)
            {
                BindData();
            }
        }

        private void BindData()
        {
            var svc = new ChannelFactory<MyServiceReference.IMyService>("BasicHttpBinding_IMyService").CreateChannel();

            var categories = svc.GetCategories();
            ListView1.DataSource = categories;
            ListView1.DataBind();
        }

        protected void ListView1_ItemUpdating(object sender, ListViewUpdateEventArgs e)
        {
            var svc = new MyServiceReference.MyServiceClient();
            var category = svc.GetCategory((int)ListView1.DataKeys[e.ItemIndex].Value);

            category.Name = (string)e.NewValues["Name"];

            svc.UpdateCategory(category);

            ListView1.EditIndex = -1;
            BindData();
        }

        protected void ListView1_ItemInserting(object sender, ListViewInsertEventArgs e)
        {
            var category = new MyServiceReference.ProductCategory();
            category.Name = (string)e.Values["Name"];
            category.rowguid = Guid.NewGuid();
            category.ModifiedDate = DateTime.Now;

            var svc = new MyServiceReference.MyServiceClient();
            svc.AddCategory(category);

            BindData();
        }

        protected void ListView1_ItemDeleting(object sender, ListViewDeleteEventArgs e)
        {
            var svc = new MyServiceReference.MyServiceClient();
            svc.DeleteCategory((int)ListView1.DataKeys[e.ItemIndex].Value);

            BindData();
        }

        protected void ListView1_ItemCanceling(object sender, ListViewCancelEventArgs e)
        {
            ListView1.EditIndex = -1;
            BindData();
        }

        protected void ListView1_ItemEditing(object sender, ListViewEditEventArgs e)
        {
            ListView1.EditIndex = e.NewEditIndex;
            BindData();
        }
    }
}

OK
[源码下载]
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原文地址：https://www.cnblogs.com/webabcd/p/1761699.html