autofac for mvc

1.首先需要安装 Autofac 和Autofac.Integration.Mvc

install-package Autofac -version5.2.0

install-package Autofac.Integration.Mvc -version 5.0.0

2.编写依赖注入和解析器类，并在该类中增加静态方法，实现注入和依赖解析，通过

System.Web.Mvc.DependencyResolver.SetResolver(new AutofacDependencyResolver(container));

来把当前的依赖注入加入到mvc框架中。

说明：

• DependencyResolver 是System.Web.Mvc 命名空间中的类，其方法SetResolver()接收一个IDependencyResolver接口类型的参数；
• AutofacDependencyResolver 是Autofac.Integration.Mvc命名空间中的类，该类实现了IDependencyResolver方法，在该类中只是把IDependencyResolver接口的两个方法GetService()和GetServices()作为虚拟方法，并未真正实现。该类是通过多个重载的构造函数来实现其生命周期的控制，并且至少接收一个ILifetimeScope类型注入容器参数来实现依赖项的解析。

3.为了使依赖解析器能够在系统启动时启动，需要在Global.asax.cs 中调用依赖解析器类中的静态方法进行初始化。

4. 控制器抽象，重建一个控制器基类，并在其中增加以来注入对象获取的方法，根据传入的接口类型自动匹配注入的依赖，从而得到该接口的实例。其他控制器通过继承该类而共享该类方法来获取依赖解析对象。

示例正代码：

1.仓储接口

using autofacdemo2.Models;
using System.Collections.Generic;
namespace autofacdemo2.Repository
{
public interface IStudentRepository
{
List<Student> GetStudents();
}
}

2.仓储实现

using autofacdemo2.Models;
using System.Collections.Generic;

namespace autofacdemo2.Repository
{
public class StudentRepository : IStudentRepository
{
private List<Student> students;
public StudentRepository()
{
students = new List<Student> {
new Student{ Id=1,Name="张三",Sex="男",Grade="二(一)班" },
new Student{ Id=2,Name="李四",Sex="女",Grade="二(二)班" },
new Student{ Id=3,Name="王五",Sex="男",Grade="二(一)班" }

};
}
public List<Student> GetStudents()
{
return students;
}
}
}

3.依赖解析类

using Autofac;
using Autofac.Integration.Mvc;
using autofacdemo2.Repository;
using System.Web.Mvc;
namespace autofacdemo2.App_Start
{
public class DependencyInject
{
private static IContainer _container;
public static IContainer Container {
get { return _container; }
}
/// <summary>
/// 注册相关接口
/// </summary>
public static void Initialise()
{
var builder = new ContainerBuilder();
builder.RegisterType<StudentRepository>().As<IStudentRepository>();
_container = builder.Build();
DependencyResolver.SetResolver(new AutofacDependencyResolver(_container));
}

}
}

4.控制器

using autofacdemo2.Repository;
using System.Linq;
using System.Web.Mvc;
namespace autofacdemo2.Controllers
{
public class HomeController : Controller
{
protected internal IStudentRepository GetStudentRepository()
{
return DependencyResolver.Current.GetService<IStudentRepository>();
}

// GET: Home
public ActionResult Index()
{
var students = GetStudentRepository();
ViewBag.Count = students.GetStudents().Count();
return View(students.GetStudents());
}
}
}

5.控制器基类

using System.Web.Mvc;

namespace autofacdemo2.Controllers
{
public class BasicController : Controller
{
// GET: Basic
protected internal TService GetService<TService>()
{
return DependencyResolver.Current.GetService<TService>();
}
}
}

6.控制器派生类

using autofacdemo2.Repository;
using System.Linq;
using System.Web.Mvc;
namespace autofacdemo2.Controllers
{
public class AutofacTestController : BasicController
{
// GET: AutofacTest
public ActionResult Index()
{
var studentrepository = GetService<IStudentRepository>();
ViewBag.Count = studentrepository.GetStudents().Count();
return View();
}
}
}