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

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

技术小胖子 2017-11-06 01:09:00 浏览521
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再接再厉VS 2008 sp1 + .NET 3.5 sp1(7) - Data Services(数据服务)


作者:webabcd


介绍
以Northwind为示例数据库,演示ADO.NET Data Services(数据服务)
  • DataService<T> - ADO.NET 数据服务的主入口点。 T 为数据源类名
  • IDataServiceConfiguration.SetEntitySetAccessRule(string name, EntitySetRights rights) - 为指定实体集设置访问规则
  • QueryInterceptorAttribute - 声明在方法上的查询拦截器
  • DataServiceContext - 数据服务的上下文
  • DataServiceQuery - 以指定的 URI 语法查询数据服务


示例
服务端
Service.cs
using System; 
using System.Data.Services; 
using System.Collections.Generic; 
using System.Linq; 
using System.ServiceModel.Web; 

using VS2008SP1.Business; 
using System.Linq.Expressions; 

// DataService<T> - ADO.NET 数据服务的主入口点。 T 为数据源类名 
public class Service : DataService<VS2008SP1.Business.NorthwindEntities> 

        // 初始化涉及服务范围的策略(仅调用一次) 
static void InitializeService() static void InitializeService(IDataServiceConfiguration config) 
        { 
                /**//* 
                 * IDataServiceConfiguration.SetEntitySetAccessRule(string name, EntitySetRights rights) - 为指定实体集设置访问规则 
                 *         name - 实体集名称(* 为全部) 
                 *         rights - 设置对指定实体集的操作权限 [System.Data.Services.EntitySetRights 枚举] 
                 * EntitySetRights.None - 权限为:无任何权限     
                 * EntitySetRights.All - 权限为:全部权限     
                 * EntitySetRights.ReadSingle - 权限为:只能读取数据集内的某一条数据 
                 * EntitySetRights.ReadMultiple - 权限为:可读取数据集内的全部数据 
                 * EntitySetRights.WriteAppend - 权限为:插入     
                 * EntitySetRights.WriteReplace - 权限为:更新     
                 * EntitySetRights.WriteDelete - 权限为:删除 
                 * EntitySetRights.WriteMerge - 权限为:合并数据     
                 * EntitySetRights.AllRead - 权限为:全部可读     
                 * EntitySetRights.AllWrite - 权限为:全部可写     
                 */ 
                config.SetEntitySetAccessRule("*", EntitySetRights.All); 
                 
                // config.SetEntitySetAccessRule("*", EntitySetRights.AllRead | EntitySetRights.AllWrite); 
        } 

        /**//* 
         *    QueryInterceptorAttribute - 声明在方法上的查询拦截器 
         *            方法名任意(不带参数),返回值必须为一个 Expression<Func<T, bool>> 表达式,T 为需要过滤的实体集类名 
         */ 
        [QueryInterceptor("Orders")] 
Expression<Func<Orders, bool>> FilterOrders() Expression<Func<Orders, bool>> FilterOrders() 
        { 
                // 本例为无论在任何情况下,返回的 Orders 都是 ContactName 为 Paul Henriot 的 Orders 
                return o => o.Customers.ContactName == "Paul Henriot"
        } 
}
 
 
1、添加、查询、更新和删除的Demo
Demo.aspx
<%@ Page Title="添加、查询、更新和删除的Demo" Language="C#" MasterPageFile="~/Site.master" AutoEventWireup="true" 
        CodeFile="Demo.aspx.cs" Inherits="DataServices_Demo" %> 

<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="Server"
</asp:Content> 
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="Server"
        <div style="margin: 10px;"
                CategoryName:<asp:TextBox ID="txtCategoryName" runat="server" /> 
                Description:<asp:TextBox ID="txtDescription" runat="server" /> 
                <asp:Button ID="btnAddCategory" runat="server" Text="添加产品类别" OnClick="btnAddCategory_Click" /> 
        </div> 
        <div style="margin: 10px;"
                <asp:GridView ID="GridView1" DataKeyNames="CategoryID" runat="server" AutoGenerateColumns="false" 
                        OnRowDeleting="GridView1_RowDeleting" OnRowCancelingEdit="GridView1_RowCancelingEdit" 
                        OnRowEditing="GridView1_RowEditing" OnRowUpdating="GridView1_RowUpdating" OnSelectedIndexChanged="GridView1_SelectedIndexChanged"
                        <Columns> 
                                <asp:BoundField DataField="CategoryID" HeaderText="ID" ReadOnly="true" /> 
                                <asp:BoundField DataField="CategoryName" HeaderText="CategoryName" /> 
                                <asp:BoundField DataField="Description" HeaderText="Description" /> 
                                <asp:CommandField ShowSelectButton="True" ShowEditButton="True" ShowDeleteButton="True"
                                </asp:CommandField> 
                        </Columns> 
                </asp:GridView> 
        </div> 
        <div style="margin: 10px;"
                <asp:GridView ID="GridView2" runat="server"
                </asp:GridView> 
        </div> 
</asp:Content>
 
Demo.aspx.cs
// 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(); 
        } 
}
 
 
2、其他知识点
Demo2.aspx
<%@ 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>
 
Demo2.aspx.cs
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)); 
        } 
}
 
 
OK
[源码下载]

      本文转自webabcd 51CTO博客,原文链接:http://blog.51cto.com/webabcd/341567,如需转载请自行联系原作者

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