在本文中，您将学到在现有 ASP.NET MVC 框架的 CRUD 项目中，如何使用 SignalR 类库，显示来自数据库的实时更新。在这一主题中，我们将重点放在在现有 ASP.NET MVC 框架的 CRUD 项目中，如何使用 SignalR 类库，显示来自数据库的实时更新。 本文系国内 ITOM 管理平台 工程师编译整理。

本主题有以下两个步骤：

1. 我们将创建一个示例应用程序来执行 CRUD 操作。

2. 我们将使用 SignalR 类库让应用实时。

那些不熟悉 SignalR 的，请访问我以前有关 的文章。

第一步：

我们需要创建一个名为 CRUD_Sample 的数据库。在示例数据库中创建一个名为 Customer 的表。

CREATE TABLE [dbo].[Customer](    [Id] [bigint] IDENTITY(1,1)NOTNULL,    [CustName] [varchar](100)NULL,    [CustEmail] [varchar](150)NULL  )

存储过程

USE [CRUD_Sample]  GO    /****** Object:  StoredProcedure [dbo].[Delete_Customer]    Script Date: 12/27/2015 1:44:05 PM ******/  SETANSI_NULLSON  GO    SETQUOTED_IDENTIFIERON  GO    -- =============================================  -- Author:      
    
       -- Create date: 
     
        -- Description: 
      
         -- =============================================  CREATE PROCEDURE [dbo].[Delete_Customer]      -- Add the parameters for the stored procedure here       @Id Bigint  AS  BEGIN      -- SET NOCOUNT ON added to prevent extra result sets from      -- interfering with SELECT statements.      SETNOCOUNTON;    -- Insert statements for procedure here      DELETE FROM [dbo].[Customers] WHERE [Id] = @Id      RETURN 1  END    GO    /****** Object:  StoredProcedure [dbo].[Get_Customer]    Script Date: 12/27/2015 1:44:05 PM ******/  SETANSI_NULLSON  GO    SETQUOTED_IDENTIFIERON  GO    -- =============================================  -- Author:      
       
          -- Create date: 
        
           -- Description: 
         
           -- ============================================= CREATE PROCEDURE [dbo].[Get_Customer] -- Add the parameters for the stored procedure here @Count INT AS BEGIN -- SET NOCOUNT ON added to prevent extra result sets from -- interfering with SELECT statements. SETNOCOUNTON; -- Insert statements for procedure here SELECT top(@Count)*FROM [dbo].[Customers] END GO /****** Object: StoredProcedure [dbo].[Get_CustomerbyID] Script Date: 12/27/2015 1:44:05 PM ******/ SETANSI_NULLSON GO SETQUOTED_IDENTIFIERON GO -- ============================================= -- Author: 
          
            -- Create date: 
           
             -- Description: 
            
              -- ============================================= CREATE PROCEDURE [dbo].[Get_CustomerbyID] -- Add the parameters for the stored procedure here @Id BIGINT AS BEGIN -- SET NOCOUNT ON added to prevent extra result sets from -- interfering with SELECT statements. SETNOCOUNTON; -- Insert statements for procedure here SELECT*FROM [dbo].[Customers] WHERE Id=@Id END GO /****** Object: StoredProcedure [dbo].[Set_Customer] Script Date: 12/27/2015 1:44:05 PM ******/ SETANSI_NULLSON GO SETQUOTED_IDENTIFIERON GO -- ============================================= -- Author: 
             
               -- Create date: 
              
                -- Description: 
               
                 -- ============================================= CREATE PROCEDURE [dbo].[Set_Customer] -- Add the parameters for the stored procedure here @CustNameNvarchar(100) ,@CustEmailNvarchar(150) AS BEGIN -- SET NOCOUNT ON added to prevent extra result sets from -- interfering with SELECT statements. SETNOCOUNTON; -- Insert statements for procedure here INSERT INTO [dbo].[Customers]([CustName],[CustEmail]) VALUES(@CustName,@CustEmail) RETURN 1 END GO /****** Object: StoredProcedure [dbo].[Update_Customer] Script Date: 12/27/2015 1:44:05 PM ******/ SETANSI_NULLSON GO SETQUOTED_IDENTIFIERON GO -- ============================================= -- Author: 
                
                  -- Create date: 
                 
                   -- Description: 
                  
                    -- ============================================= CREATE PROCEDURE [dbo].[Update_Customer] -- Add the parameters for the stored procedure here @Id Bigint ,@CustNameNvarchar(100) ,@CustEmailNvarchar(150) AS BEGIN -- SET NOCOUNT ON added to prevent extra result sets from -- interfering with SELECT statements. SETNOCOUNTON; -- Insert statements for procedure here UPDATE [dbo].[Customers] SET[CustName] = @CustName,[CustEmail]= @CustEmail WHERE [Id] = @Id RETURN 1 END GO
                  
                 
                
               
              
             
            
           
          
         
        
       
      
     
    

启动 MVC 项目

创建示例应用程序，我们需要 Visual Studio 2012 或更高版本，并且该服务器平台必须支持 .NET 4.5。

步骤 1:

Step 2:

Step 3:

点击 OK，Visual Studio 将会创建一个新的 ASP.NET 工程。

使用通用类库

使用通用功能，我们可以减少代码数量。

namespace WebApplication1.Repository  {      interfaceIRepository < T > : IDisposablewhereT: class      {          IEnumerable < T > ExecuteQuery(stringspQuery, object[] parameters);          TExecuteQuerySingle(stringspQuery, object[] parameters);          intExecuteCommand(stringspQuery, object[] parameters);      }  }

接口 IRepository

显示一个通用类库的 T 型接口，它是 SQL 实体的 LINQ。它提供了一个基本的界面操作，如 Insert, Update, Delete, GetById and GetAll。

IDisposable

IDisposable接口提供了一种机制，释放非托管资源。

where T : class

这是制约泛型参数的一类。点击查看。

类型参数必须是引用类型;这也适用于任何类，接口，委托或数组类型。

namespace WebApplication1.Repository  {      public class GenericRepository < T > : IRepository < T > whereT: class      {          Customer_Entities context = null;          privateDbSet < T > entities = null;          public GenericRepository(Customer_Entities context)          {              this.context = context;              entities = context.Set < T > ();          }          ///
          /// Get Data From Database          ///
     
      Use it when to retive data through a stored procedure
               ///
          public IEnumerable < T > ExecuteQuery(stringspQuery, object[] parameters)          {              using(context = newCustomer_Entities())              {                      returncontext.Database.SqlQuery < T > (spQuery, parameters).ToList();              }          }          ///
          /// Get Single Data From Database          ///
     
      Use it when to retive single data through a stored procedure
               ///
          public TExecuteQuerySingle(stringspQuery, object[] parameters)          {              using(context = newCustomer_Entities())              {                  returncontext.Database.SqlQuery < T > (spQuery, parameters).FirstOrDefault();              }          }          ///
          /// Insert/Update/Delete Data To Database          ///
     
      Use it when to Insert/Update/Delete data through a stored procedure
               ///
          public intExecuteCommand(stringspQuery, object[] parameters)          {              int result = 0;              try              {                  using(context = newCustomer_Entities())                  {                      result = context.Database.SqlQuery < int > (spQuery, parameters).FirstOrDefault();                  }              }              catch              {}              return result;          }          private bool disposed = false;          protected virtualvoid Dispose(bool disposing)          {              if (!this.disposed)              {                  if (disposing)                  {                      context.Dispose();                  }              }              this.disposed = true;          }          public void Dispose()          {              Dispose(true);              GC.SuppressFinalize(this);          }      }  }

使用 middle-tire 结构

namespace WebApplication1.Services  {      public partial class CustomerService      {          privateGenericRepository < Customer > CustRepository;          //CustomerRepositoryCustRepository;          public CustomerService()          {              this.CustRepository = newGenericRepository < Customer > (newCustomer_Entities());          }          public IEnumerable < Customer > GetAll(object[] parameters)          {              stringspQuery = "[Get_Customer] {0}";              returnCustRepository.ExecuteQuery(spQuery, parameters);          }          public CustomerGetbyID(object[] parameters)          {              stringspQuery = "[Get_CustomerbyID] {0}";              returnCustRepository.ExecuteQuerySingle(spQuery, parameters);          }          public int Insert(object[] parameters)          {              stringspQuery = "[Set_Customer] {0}, {1}";              returnCustRepository.ExecuteCommand(spQuery, parameters);          }          public int Update(object[] parameters)          {              stringspQuery = "[Update_Customer] {0}, {1}, {2}";              returnCustRepository.ExecuteCommand(spQuery, parameters);          }          public int Delete(object[] parameters)          {              stringspQuery = "[Delete_Customer] {0}";              returnCustRepository.ExecuteCommand(spQuery, parameters);          }      }  }

在 MVC 架构应用程序中使用通用库

namespace WebApplication1.Controllers  {      public class HomeController: Controller      {          private CustomerServiceobjCust;          //CustomerRepositoryCustRepository;          public HomeController()              {                  this.objCust = newCustomerService();              }              // GET: Home          public ActionResult Index()          {              int Count = 10;              object[] parameters = {                  Count              };              var test = objCust.GetAll(parameters);              return View(test);          }          public ActionResult Insert()          {              return View();          }          [HttpPost]          public ActionResult Insert(Customer model)          {              if (ModelState.IsValid)              {                  object[] parameters = {                      model.CustName,                      model.CustEmail                  };                  objCust.Insert(parameters);              }              return RedirectToAction("Index");          }          public ActionResult Delete(int id)          {              object[] parameters = {                  id              };              this.objCust.Delete(parameters);              return RedirectToAction("Index");          }          public ActionResult Update(int id)          {              object[] parameters = {                  id              };              return View(this.objCust.GetbyID(parameters));          }          [HttpPost]          public ActionResult Update(Customer model)          {              object[] parameters = {                  model.Id,                  model.CustName,                  model.CustEmail              };              objCust.Update(parameters);              return RedirectToAction("Index");          }          protected override void Dispose(bool disposing)          {              base.Dispose(disposing);          }      }  }

在 MVC 架构应用程序中使用视图

Index

@model IList  
    
       @{  ViewBag.Title = "Index";  }        
           
                  
                   
                 
        
           @Html.ActionLink("New Customer", "Insert", "Home")                
            ID Name Email ID Delete Update    @if (Model != null) { foreach (var item in Model) {  @item.Id @item.CustName @item.CustEmail @Html.ActionLink("Delete", "Delete", "Home", new { id = @item.Id }, null) @Html.ActionLink("Update", "Update", "Home", new { id = @item.Id }, null)  } }    
            
          
         
        
       
      
     
    

Insert

@model WebApplication1.Models.Customer  @{  ViewBag.Title = "Insert";  }    
      
    
   
    
  
    
   
    
  
    
      
     
          
      
          @using (Html.BeginForm("Insert", "Home", FormMethod.Post))  {  @*                  
*@                    
  }                
                     
        
                               
ID
                               
@Html.TextBoxFor(m =>m.Id)
                          
        
                               
Name 
                               
@Html.TextBoxFor(m =>m.CustName) 
                          
                          
                               
Email ID 
                               
@Html.TextBoxFor(m =>m.CustEmail) 
                          
                          
                               
  
                          
       
                
      
     
      
     
       
     
  @Html.ActionLink("Home", "Index", "Home")    
    

Update

@model WebApplication1.Models.Customer  @{  ViewBag.Title = "Update";  }      
      
    
   
    
  
    
   
    
  
    
      
     
          
      
           @using (Html.BeginForm("Update", "Home", FormMethod.Post))  {                        
  }                    
                     
                          
                               
Name
                               
Email ID
                               
Update
                          
                     
                     
                          
         
@Html.TextBoxFor(m =>m.CustName)
                               
@Html.TextBoxFor(m =>m.CustEmail)
                               
 
           
        
                     
                
      
     
  
    

步骤2:

启动 SignalR

第一件事是获得 NuGet 参照。

在 NuGet 上获得。

安装 Microsoft.AspNet.SignalR 包

注册 SignalR 中间件

安装后需要创建 OwinStartup 类。

下面的代码将一段简单中间件向 OWIN 管道，实现接收 Microsoft.Owin.IOwinContext 实例的功能。

当服务器收到一个 HTTP 请求，OWIN 管道调用中间件。中间件设置内容类型的响应和写响应体。

Startup.cs

using System;  using System.Threading.Tasks;  using Microsoft.Owin;  using Owin;  [assembly: OwinStartup(typeof (WebAppSignalR.Startup))]  namespace WebAppSignalR  {      public class Startup      {          public void Configuration(IAppBuilder app)          {              app.MapSignalR();          }      }  }

创建使用 Hub 类

完成前面的过程之后，创建一个 Hub。一个SignalR Hub 让从服务器到客户端连接，并从客户端到服务器的远程过程调用（RPC）。

CustomerHub.cs

using System;  using System.Collections.Generic;  using System.Linq;  using System.Web;  using Microsoft.AspNet.SignalR;  using Microsoft.AspNet.SignalR.Hubs;  namespace WebApplication1.Hubs  {      public class CustomerHub: Hub      {          [HubMethodName("broadcastData")]          public static void BroadcastData()          {              IHubContext context = GlobalHost.ConnectionManager.GetHubContext < CustomerHub > ();              context.Clients.All.updatedData();          }      }  }

代码说明

IHubContext context = GlobalHost.ConnectionManager.GetHubContext
    
     ();
    

获得 CustomerHub context:

context.Clients.All.updatedData();

它请求 SignalR 的客户端部分，并告诉它执行 JavaScript 的 updatedData（）方法。

修改现有视图 Let’s Modify our Existing View

修改一部分索引视图，将通过局部视图显示数据。

Index

@model IList < WebApplication1.Models.Customer > @  {      ViewBag.Title = "Index";  } < linkhref = "~/Content/bootstrap/css/bootstrap.min.css"  rel = "stylesheet" / > < divclass = "clearfix" > & nbsp; < /div> < divclass = "clearfix" > & nbsp; < /div> < divclass = "container" > < divclass = "table-responsive" > @Html.ActionLink("New Customer", "Insert", "Home") < hr / > < divid = "dataTable" > < /div> < /div> < divclass = "clearfix" > & nbsp; < /div> < /div>  @section JavaScript  { < scriptsrc = "~/Scripts/jquery.signalR-2.2.0.min.js" > < /script> < scriptsrc = "/signalr/hubs" > < /script> < scripttype = "text/javascript" > $(function ()      {          // Reference the hub.          var hubNotif = $.connection.customerHub;          // Start the connection.          $.connection.hub.start().done(function ()          {              getAll();          });          // Notify while anyChanges.          hubNotif.client.updatedData = function ()          {              getAll();          };      });      function getAll()      {          var model = $('#dataTable');          $.ajax(          {              url: '/home/GetAllData',              contentType: 'application/html ; charset:utf-8',              type: 'GET',              dataType: 'html'          }).success(function (result)          {              model.empty().append(result);          }).error(function (e)          {              alert(e);          });      } < /script>  }

局部视图

    
       @if (Model != null) { foreach (var item in Model) {          
 } } 
           
                
                     
ID
                     
Name
                     
Email ID
                     
Delete
                     
Update
                
           
           
      
                     
@item.Id
                     
@item.CustName
                     
@item.CustEmail
                     
@Html.ActionLink("Delete", "Delete", "Home", new { id = @item.Id }, null)
                     
@Html.ActionLink("Update", "Update", "Home", new { id = @item.Id }, null)
                
     
          

修改现有 Controller

主 Controller：

在主 Controller，我们将添加一个名为 GetAllDaTa（）的方法。这是方法。

[HttpGet]  public ActionResult GetAllData()  {      int Count = 10;      object[] parameters = {          Count      };      var test = objCust.GetAll(parameters);      return PartialView("_DataList", test);  }

在这里，返回局部视图返回的数据列表，且只返回空。

// GET: Home  public ActionResult Index()  {     return View();  }

主 Controller

public class HomeController: Controller  {      private CustomerService objCust;      //CustomerRepositoryCustRepository;      public HomeController()      {          this.objCust = newCustomerService();      }      // GET: Home      public ActionResult Index()      {          return View();      }      [HttpGet]      public ActionResult GetAllData()      {          int Count = 10;          object[] parameters = {              Count          };          var test = objCust.GetAll(parameters);          return PartialView("_DataList", test);      }      public ActionResult Insert()      {          return View();      }      [HttpPost]      public ActionResult Insert(Customer model)      {          if (ModelState.IsValid)          {              object[] parameters = {                  model.CustName,                  model.CustEmail              };              objCust.Insert(parameters);          }          //Notify to all          CustomerHub.BroadcastData();          return RedirectToAction("Index");      }      public ActionResult Delete(int id)      {          object[] parameters = {              id          };          this.objCust.Delete(parameters);          //Notify to all          CustomerHub.BroadcastData();          return RedirectToAction("Index");      }      public ActionResult Update(int id)      {          object[] parameters = {              id          };          return View(this.objCust.GetbyID(parameters));      }      [HttpPost]      public ActionResult Update(Customer model)      {          object[] parameters = {              model.Id,              model.CustName,              model.CustEmail          };          objCust.Update(parameters);          //Notify to all          CustomerHub.BroadcastData();          returnRedirectToAction("Index");      }      protected override void Dispose(bool disposing)      {          base.Dispose(disposing);      }  }

输出

希望能够帮助到您。

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