再接再厉VS 2008 sp1 + .NET 3.5 sp1(7) - Data Services(数据服务)

// 客户端用到的只有以下两个类 
// System.Data.Services.Client.DataServiceContext - 数据服务的上下文 
// System.Data.Services.Client.DataServiceQuery - 以指定的 URI 语法查询数据服务 

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

using MyDataService; 

public partial  class DataServices_Demo : System.Web.UI.Page 
{ 
        // ADO.NET 数据服务的地址 
        Uri _uri =  new Uri( "http://localhost:7002/DataServices/Service.svc/", UriKind.Absolute); 

void Page_Load() void Page_Load(object sender, EventArgs e) 
        { 
                 if (!Page.IsPostBack) 
                { 
                        BindData(); 
                } 
        } 

        void BindData() 
        { 
                // NorthwindEntities - 继承自 DataServiceContext ，其构造函数的参数为数据服务的 URI 地址 
                NorthwindEntities ctx =  new NorthwindEntities(_uri); 

                // 将 System.Data.Services.Client.DataServiceQuery<Categories> 绑定到 Gridview1 
                GridView1.DataSource = ctx.Categories; 
                GridView1.DataBind(); 
        } 

void btnAddCategory_Click() void btnAddCategory_Click(object sender, EventArgs e) 
        { 
                NorthwindEntities ctx =  new NorthwindEntities(_uri); 

                Categories category =  new Categories(); 
                category.CategoryName = txtCategoryName.Text; 
                category.Description = txtDescription.Text; 

                // DataServiceContext.Timeout - 超时时间 
                // DataServiceContext.MergeOption - 当前数据上下文与数据服务的数据的同步选项 [System.Data.Services.Client.MergeOption 枚举] 
                //         AppendOnly - 追加。默认值 
                //         OverwriteChanges - 以新结果为准 
                //         PreserveChanges - 以原结果为准 
                //         NoTracking - 取消变更跟踪，不会使用 ObjectStateManager，减少执行查询的时间，所有返回的实体将是分离的状态（detached state） 
                ctx.MergeOption = System.Data.Services.Client.MergeOption.AppendOnly; 

                ctx.AddToCategories(category); 

                 for (int i = 0; i < 10; i++) 
                { 
                        var product =  new Products() { ProductName =  "测试用" + i.ToString() }; 
                        product.Categories = category; 

                        ctx.AddToProducts(product); 

                        // DataServiceContext.SetLink(Object source,  string sourceProperty, Object target) - 在指定对象上创建新的连接，Added状态，SaveChanges() 的时候会一起发送到数据服务。多对一关系 
                        //         source - 源对象 
                        //         sourceProperty - 源对象上的属性，用于标识目标对象的类型 
                        //         target - 目标对象 
                        ctx.SetLink(product,  "Categories", category); 
                        // DataServiceContext.AddLink(Object source,  string sourceProperty, Object target) - 在指定对象上创建新的连接，Added状态，SaveChanges() 的时候会一起发送到数据服务。一对多关系 
                        // DataServiceContext.DeleteLink(Object source,  string sourceProperty, Object target) - 在指定的对象上删除连接，Deleted状态，SaveChanges() 的时候会一起发送到数据服务 
                } 

                // DataServiceContext.SaveChanges() - 将所有更新保存到相关存储区中 
                //         SaveChangesOptions.Batch - 一个 http 提交所有操作 
                //         SaveChangesOptions.ContinueOnError - 一个 http 一个操作，某操作出错仍将处理后续操作（不能与 Batch 共存） 
                //         SaveChangesOptions.ReplaceOnUpdate -    
                //         SaveChangesOptions.None - 出错则停止 
                ctx.SaveChanges(System.Data.Services.Client.SaveChangesOptions.Batch); 

                Page.ClientScript.RegisterStartupScript(this.GetType(),  "js",  "alert('CategoryID: " + category.CategoryID + "');", true); 

                GridView1.EditIndex = -1; 
                BindData(); 
        } 

void GridView1_RowDeleting() void GridView1_RowDeleting(object sender, GridViewDeleteEventArgs e) 
        { 
                NorthwindEntities ctx =  new NorthwindEntities(_uri); 

                var categoryId = (int)GridView1.DataKeys[e.RowIndex].Value; 

                var category = ctx.Categories.Where(p => p.CategoryID == categoryId).First(); 

                // DataServiceContext.LoadProperty(Object entity,  string propertyName) - 加载指定对象的指定实体属性 
                //         entity - 包含要加载的实体属性的实体 
                //         propertyName - 需要加载的实体属性的名称 
                ctx.LoadProperty(category,  "Products"); 
                foreach (var product  in category.Products) 
                { 
                        ctx.DeleteObject(product); 
                } 

                ctx.DeleteObject(category); 

                ctx.SaveChanges(); 

                GridView1.EditIndex = -1; 
                BindData(); 
        } 

void GridView1_SelectedIndexChanged() void GridView1_SelectedIndexChanged(object sender, EventArgs e) 
        { 
                NorthwindEntities ctx =  new NorthwindEntities(_uri); 

                var categoryId = (int)GridView1.SelectedDataKey.Value; 

                // 查找当前选中的类别下的产品集合 
                var products = ctx.Products.Where(p => p.Categories.CategoryID == categoryId); 

                // 将 System.Linq.IQueryable<Products> 绑定到 GridView2 
                GridView2.DataSource = products; 
                GridView2.DataBind(); 
        } 

void GridView1_RowUpdating() void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e) 
        { 
                NorthwindEntities ctx =  new NorthwindEntities(_uri); 

                var categoryId = (int)GridView1.DataKeys[e.RowIndex].Value; 

                var category = ctx.Categories.Where(p => p.CategoryID == categoryId).First(); 

                category.CategoryName = ((TextBox)GridView1.Rows[e.RowIndex].Cells[1].Controls[0]).Text; 
                category.Description = ((TextBox)GridView1.Rows[e.RowIndex].Cells[2].Controls[0]).Text; 

                ctx.UpdateObject(category); 
                ctx.SaveChanges(); 

                GridView1.EditIndex = -1; 
                BindData(); 
        } 

void GridView1_RowEditing() void GridView1_RowEditing(object sender, GridViewEditEventArgs e) 
        { 
                GridView1.EditIndex = e.NewEditIndex; 
                BindData(); 
        } 

void GridView1_RowCancelingEdit() void GridView1_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e) 
        { 
                GridView1.EditIndex = -1; 
                BindData(); 
        } 
}

<%@ Page Title= "其它" Language= "C#" MasterPageFile= "~/Site.master" AutoEventWireup= "true" 
        CodeFile= "Demo2.aspx.cs"  Inherits= "DataServices_Demo2" %> 

<asp:Content ID= "Content1" ContentPlaceHolderID= "head" runat= "Server"> 
</asp:Content> 
<asp:Content ID= "Content2" ContentPlaceHolderID= "ContentPlaceHolder1" runat= "Server"> 
        <div id= "result" runat= "server"> 
        </div> 
</asp:Content>

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

using MyDataService; 
using System.Data.Services.Client; 

public partial  class DataServices_Demo2 : System.Web.UI.Page 
{ 
        // ADO.NET 数据服务的地址 
        Uri _uri =  new Uri( "http://localhost:7002/DataServices/Service.svc/", UriKind.Absolute); 

void Page_Load() void Page_Load(object sender, EventArgs e) 
        { 
                // 以 URI 语法的方式查询 ADO.NET 数据服务 
                Demo(); 

                // 异步方式查询 ADO.NET 数据服务 
                Demo2(); 

                // 演示查询拦截器的 Demo 
                Demo3(); 

                // 演示以 JSON 作为响应格式的 Demo 
                Demo4(); 
        } 

        void Demo() 
        { 
                DataServiceContext ctx =  new DataServiceContext(_uri); 

                // 以 URI 语法的方式查询 ADO.NET 数据服务，详细语法参看 MSDN 
                // http://[Url]/[ServiceName]/[EntityName]/[NavigationOptions]?[QueryOptions] 
                DataServiceQuery<Categories> categories = ctx.CreateQuery<Categories>( "/Categories"); 

                foreach (var c  in categories) 
                { 
                        result.InnerHtml += c.CategoryID +  ","; 
                } 

                result.InnerHtml +=  "<br /><br />"; 
        } 

        void Demo2() 
        { 
                DataServiceContext ctx =  new DataServiceContext(_uri); 

                DataServiceQuery<Categories> query = ctx.CreateQuery<Categories>( "/Categories"); 

                // 异步方式查询 ADO.NET 数据服务 
                query.BeginExecute( 
                        delegate(IAsyncResult ar) 
                        { 
                                foreach (var c  in query.EndExecute(ar)) 
                                { 
                                        result.InnerHtml += c.CategoryID +  ","; 
                                } 

                                result.InnerHtml +=  "<br /><br />"; 
                        }, 
                         null); 
        } 

        void Demo3() 
        { 
                NorthwindEntities ctx =  new NorthwindEntities(_uri); 

                // 因为设置了查询拦截器，所以只能收到 ContactName 为 Paul Henriot 的 Orders 
                foreach (var o  in ctx.Orders) 
                { 
                        result.InnerHtml += o.OrderID +  ","; 
                } 

                result.InnerHtml +=  "<br /><br />"; 
        } 

        void Demo4() 
        { 
                System.Net.WebClient client =  new System.Net.WebClient(); 
                // 需要以 json 格式返回结果的话，需要设置以下 header 
                client.Headers.Add( "accept",  "application/json"); 
                // client.Headers.Add( "accept",  "application/xml"); xml/atom 格式 
                // client.Headers.Add( "accept",  "*/*"); xml/atom 格式，默认值 
                result.InnerHtml += HttpUtility.HtmlEncode(client.DownloadString(_uri)); 
        } 
}