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。
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:
Getting Started with MVC
Step 2:
Web application
Step 3:
select template
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";
}
