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 OneAPM 工程师编译整理。
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本主题有以下两个步骤：
我们将创建一个示例应用程序来执行 CRUD 操作。
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 SignalR 概述 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。点击查看更多。
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";
}
