新建MVC项目，添加程序集引用
定义接口ILog
public interface ILog { string Save(string message); }
类TxtLog实现接口ILog
public class TxtLog:ILog { public string Save(string message) { return "TxtLog"; } }
类DbLog实现接口ILog
public class DbLog:ILog { public string Save(string message) { return "DbLog"; } }
修改HomeController里面Index方法，改为如下，注意引用
private ILog _log; //构造器注入 public HomeController(ILog log) { _log = log; } // GET: /Home/ public ActionResult Index() { ViewBag.Message = "Welcome to ASP.NET MVC!"; ViewBag.LogTypeName = _log.Save(""); return View(); }
修改页面Index.cshtml ，添加如下代码
<!DOCTYPE html> <html> <head> <meta name="viewport" content="width=device-width" /> <title>Index</title> </head> <body> <div> <h2>ILog's type name is @ViewBag.LogTypeName</h2> </div> </body> </html>
修改Global.asax，在Application_Start()方法里面添加如下代码，注意引用Autofac、Autofac.Integration.Mvc以及别的引用
protected void Application_Start() { AreaRegistration.RegisterAllAreas(); WebApiConfig.Register(GlobalConfiguration.Configuration); FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters); RouteConfig.RegisterRoutes(RouteTable.Routes); BundleConfig.RegisterBundles(BundleTable.Bundles); //依赖注入 ContainerBuilder builder = new ContainerBuilder(); builder.RegisterType<TxtLog>().As<ILog>().InstancePerHttpRequest(); builder.RegisterControllers(Assembly.GetExecutingAssembly()); builder.RegisterAssemblyTypes(Assembly.GetExecutingAssembly()).AsImplementedInterfaces(); var container = builder.Build(); DependencyResolver.SetResolver(new AutofacDependencyResolver(container)); }
注意： DependencyResolver.SetResolver(new AutofacDependencyResolver(container)); 这个必须放在builder.RegisterControllers(Assembly.GetExecutingAssembly());的后面，不然会出现错误：没有为该对象定义无参数的构造函数。
运行结果
