MVC执行流程

路由的扩展

我理解的路由作用有以下几个

•  Seo优化，用“/”分开的url爬虫更爱吃
•  物理和逻辑文件分离,url不再按照文件路径映射
•  Controller，Action的选择

MVC路由的扩展

实话实说MVC的路由我很少去做扩展，在MVC4时代，还会去重写掉url的大小写，而在MVC5之后，MVC自带了配置去小写化url。不过有一个配置还是必须要提一下那就是Area，在你的系统达到一定规模之后，Controllers通过Area来管理将会变得更容易。这里给出我的Area扩展，很简单但是很重要,注意子类必须以AreaRegistration结尾，同样遵循约定有限于配置的原则，当然你也可以重写。

public abstract class AreaRegistrationBase : AreaRegistration    {        public override string AreaName        {            get {                var item = GetType().Name;                return item.Replace("AreaRegistration", "");            }        }         public override void RegisterArea(AreaRegistrationContext context)        {             context.MapLowerCaseUrlRoute(             AreaName + "_default",             AreaName.ToLower() + "/{controller}/{action}/{id}",             new { action = "Index", id = UrlParameter.Optional }             );             GlobalConfiguration.Configuration.Routes.MapHttpRoute(                 AreaName + "Api",                 "api/" + AreaName + "/{controller}/{action}/{id}",                 new { area = AreaName, id = RouteParameter.Optional, namespaceName = new[] { this.GetType().Namespace } }             );        }    }

WebApi路由的扩展

上面MVC的路由也注册了Api的路由，当然还有更好的方法，由于WebApi,基本不需要Url.Action和HtmlAction，这种路由出栈的策略，不需要去通过路由生成Url,所以

我们只需要做到路由的解析即可，并且webapi并没有提供自带的area机制，所以我扩展了DefaultHttpControllerSelector，获取到路由中area和controller参数

然后完成拼接，然后反射类型查找，在最开始时候预先缓存了所有controller，所以性能还不错，由于原代码是反编译获得，所以linq部分有点糟糕，等我回公司拿到源代码再修改。

using System; using System.Collections.Generic; using System.Linq; using System.Net.Http; using System.Text; using System.Web.Http; using System.Web.Http.Controllers; using System.Web.Http.Dispatcher;  namespace Coralcode.Webapi.Route {   public class AreaHttpControllerSelector : DefaultHttpControllerSelector   {     public static string CoralControllerSuffix = "ApiController";     private readonly HttpConfiguration _configuration;     private readonly Lazy<ILookup<string, Type>> _apiControllerTypes;      private ILookup<string, Type> ApiControllerTypes     {       get       {         return this._apiControllerTypes.Value;       }     }      public AreaHttpControllerSelector(HttpConfiguration configuration)       : base(configuration)     {       this._configuration = configuration;       this._apiControllerTypes = new Lazy<ILookup<string, Type>>(new Func<ILookup<string, Type>>(this.GetApiControllerTypes));     }      private ILookup<string, Type> GetApiControllerTypes()     {       return Enumerable.ToLookup<Type, string, Type>((IEnumerable<Type>) ServicesExtensions.GetHttpControllerTypeResolver(this._configuration.Services).GetControllerTypes(ServicesExtensions.GetAssembliesResolver(this._configuration.Services)), (Func<Type, string>) (t => t.Name.ToLower().Substring(0, t.Name.Length - AreaHttpControllerSelector.CoralControllerSuffix.Length)), (Func<Type, Type>) (t => t));     }      public override HttpControllerDescriptor SelectController(HttpRequestMessage request)     {       string controllerName = this.GetControllerName(request);       if (!string.IsNullOrWhiteSpace(controllerName))       {         List<Type> list = Enumerable.ToList<Type>(this.ApiControllerTypes[controllerName.ToLower()]);         if (Enumerable.Any<Type>((IEnumerable<Type>) list))         {           IDictionary<string, object> values = HttpRequestMessageExtensions.GetRouteData(request).Values;           string endString;           if (values.Count > 1)           {             StringBuilder stringBuilder = new StringBuilder();             if (values.ContainsKey("area"))             {               stringBuilder.Append('.');               stringBuilder.Append(values["area"]);               stringBuilder.Append('.');               stringBuilder.Append("controllers");             }             if (values.ContainsKey("controller"))             {               stringBuilder.Append('.');               stringBuilder.Append(values["controller"]);               stringBuilder.Append(AreaHttpControllerSelector.CoralControllerSuffix);             }             endString = stringBuilder.ToString();           }           else             endString = string.Format(".{0}{1}", (object) controllerName, (object) AreaHttpControllerSelector.CoralControllerSuffix);           Type controllerType = Enumerable.FirstOrDefault<Type>((IEnumerable<Type>) Enumerable.OrderBy<Type, int>(Enumerable.Where<Type>((IEnumerable<Type>) list, (Func<Type, bool>) (t => t.FullName.EndsWith(endString, StringComparison.CurrentCultureIgnoreCase))), (Func<Type, int>) (t => Enumerable.Count<char>((IEnumerable<char>) t.FullName, (Func<char, bool>) (s => (int) s == 46)))));           if (controllerType != (Type) null)             return new HttpControllerDescriptor(this._configuration, controllerName, controllerType);         }       }       return base.SelectController(request);     }   } }

Controller激活

Controller激活这部分是MVC和Ioc结合的核心，Ioc有三大部分

•  Register 类型的发现和注册，解决如何发现那些类型是需要注册的和如何注册，这里我采用Attribute的方式去发现，用Unity自带的注册方法注册
•  Resolve  类型的解析,如何知道某个类型和将其实例化
•  LiftTime  如何控制实例的生命周期，例如是否使用单例，生命周期也采用Unity自带的，主要用到单例和每次解析都一个实例

MVC需要和Ioc激活首先我们关注的就是哪里注册和哪里去实例化，由于MVC使用的是约定优先于配置的方式，所有的Controller都是以“Controller”结尾，所以这里我直接加载

程序集，然后找到所有类型以Controller结尾的去注册就好了，激活的话有以下三种方式，难易程度依次递增，嵌套深度也依次递增，这里我采用重写

默认DefaultControllerFactory的方式去激活，这样既可以用自己的也结合其他机制去实现,其他方式大家可以自行扩展。

•  ControllerFactory
•  IControllerActivetor
•  IDependencyResolver

using Coralcode.Framework.Aspect.Unity; using Coralcode.Mvc.Resources; using System; using System.Web; using System.Web.Mvc; using System.Web.Routing;  namespace Coralcode.Mvc.ControllerFactory {   public class UnityControllerFactory : DefaultControllerFactory   {     public override IController CreateController(RequestContext requestContext, string controllerName)     {       return base.CreateController(requestContext, controllerName);     }      protected override IController GetControllerInstance(RequestContext requestContext, Type controllerType)     {       if (controllerType == (Type) null)         throw new HttpException(404, Messages.MvcBase_NotFoundPage);       if (!UnityService.HasRegistered(controllerType))         return base.GetControllerInstance(requestContext, controllerType);       return (IController) UnityService.Resolve(controllerType);     }   } } //webapi 激活如下  using Coralcode.Framework.Aspect.Unity; using System; using System.Net.Http; using System.Web.Http.Controllers; using System.Web.Http.Dispatcher;  namespace Coralcode.Webapi.ControllerFactory {   public class UnityControllerActivator : IHttpControllerActivator   {     public IHttpController Create(HttpRequestMessage request, HttpControllerDescriptor controllerDescriptor, Type controllerType)     {       IHttpController httpController = (IHttpController) UnityService.Resolve(controllerType);       HttpRequestMessageExtensions.RegisterForDispose(request, httpController as IDisposable);       return httpController;     }   } }

Filter执行

LogFilter

这里基本上都是Mvc的源代码，只是增加了一个日志功能而已，扒MVC源代码大家一定去尝试

using Coralcode.Framework.Log; using System; using System.Web; using System.Web.Mvc;  namespace Coralcode.Mvc.Filters {   [AttributeUsage(AttributeTargets.Class | AttributeTargets.Method)]   public class LogExceptionAttribute : HandleErrorAttribute   {     public override void OnException(ExceptionContext filterContext)     {       if (filterContext == null)         throw new ArgumentNullException("filterContext");       Exception exception = filterContext.Exception;       LoggerFactory.Instance.Error(exception.ToString());       if (filterContext.IsChildAction || filterContext.ExceptionHandled || (!filterContext.HttpContext.IsCustomErrorEnabled || new HttpException((string) null, exception).GetHttpCode() != 500) || !this.ExceptionType.IsInstanceOfType((object) exception))         return;       this.HandlerViewResultException(filterContext);     }      private void HandlerViewResultException(ExceptionContext filterContext)     {       string controllerName = (string) filterContext.RouteData.Values["controller"];       string actionName = (string) filterContext.RouteData.Values["action"];       HandleErrorInfo model = new HandleErrorInfo(filterContext.Exception, controllerName, actionName);       ExceptionContext exceptionContext = filterContext;       ViewResult viewResult1 = new ViewResult();       viewResult1.ViewName = this.View;       viewResult1.MasterName = this.Master;       viewResult1.ViewData = (ViewDataDictionary) new ViewDataDictionary<HandleErrorInfo>(model);       viewResult1.TempData = filterContext.Controller.TempData;       ViewResult viewResult2 = viewResult1;       exceptionContext.Result = (ActionResult) viewResult2;       filterContext.ExceptionHandled = true;       filterContext.HttpContext.Response.Clear();       filterContext.HttpContext.Response.StatusCode = 500;       filterContext.HttpContext.Response.TrySkipIisCustomErrors = true;     }   } }

ResultFilter

这里统一处理了Ajax请求返回数据以ResultMessage返回，如果不是JsonResult选择忽略,具体设计初衷可以看Controller设计那一节.

using Coralcode.Framework.Models; using Coralcode.Mvc.ActionResults; using System.Web.Mvc;  namespace Coralcode.Mvc.Filters {   public class ResultMessageAttribute : ActionFilterAttribute   {     public override void OnResultExecuting(ResultExecutingContext filterContext)     {       JsonResult jsonResult = (JsonResult) (filterContext.Result as CustomJsonResult) ?? filterContext.Result as JsonResult;       if (jsonResult == null)         return;       jsonResult.Data = this.GetResultMessage(jsonResult.Data);       filterContext.Result = (ActionResult) jsonResult;     }      private object GetResultMessage(object data)     {       if (data is BaseMessage)         return data;       return (object) new ResultMessage(ResultState.Success, "Success", data);     }   } }

Action执行

提高并发利器，最佳使用方式，这里详细的介绍可以结合Artec的Controller同步和异步这一节,其中我个人推荐的就是采用返回Task<ActionResult>。

ValueProvider和ModelBinder

这里会将Url中的参数作为Model绑定的数据源。在做三级菜单的时候可以体现出用途,例如我首先在数据字典中添加如下数据

var newsType = new Glossary()            {                Key = "NewsType",                Value = "NewsType",                Description = "新闻",                Seq = 0,                Title = "新闻类型",                ParentId = -1,            };            _glossaryService.Add(newsType);            _glossaryService.Add(new Glossary()            {                Key = "RecentNews",                Value = "RecentNews",                Description = "新闻类型",                Seq = 1,                Title = "最新活动",                ParentId = newsType.Id,            });            _glossaryService.Add(new Glossary()            {                Key = "UserActivity",                Value = "UserActivity",                Description = "新闻类型",                Seq = 2,                Title = "会员活动",                ParentId = newsType.Id,            });            _glossaryService.Add(new Glossary()            {                Key = "OnlineMarket",                Value = "OnlineMarket",                Description = "新闻类型",                Seq = 3,                Title = "在线商城",                ParentId = newsType.Id,            });            _glossaryService.Add(new Glossary()            {                Key = "AboutUs",                Value = "AboutUs",                Description = "新闻类型",                Seq = 4,                Title = "关于我们",                ParentId = newsType.Id,            });            Repository.UnitOfWork.Commit();

然后从字段中读出数据去添加菜单

var newsMenu = Regist("新闻管理", "/portal/home/handerindex?menuId=" + systemManagerMenu.Identify + "-NewsType",              systemManagerMenu.Identify, systemManagerMenu.Identify + "-NewsType");          //新闻管理          _glossaryService.GetFiltered("新闻类型").ForEach(item =>          {              Regist(item.Title,string.Format( "/portal/news/index?typeid={0}&type={1}" , item.Id,item.Title),                  newsMenu.Identify, newsMenu.Identify + "-" + item.Id);          });

加载三级菜单

/// <summary>       /// 处理界面       /// </summary>       /// <returns></returns>       public ActionResult HanderIndex(string menuId)       {           ViewBag.Tree = string.Empty;           //TODO:请求两次，待处理           if (menuId == null)               return View();           var items = _menuService.GetChildrenMenus(menuId);            ViewBag.Tree = JsonConvert.SerializeObject(items);            return View();       }

界面如图

然后在Search和ViewModel中有一个字段是TypeId，这样在List,PageSearch，AddOrEdit中就可以自动绑定值了。

public  class NewsSearch:SearchBase    {         public long? TypeId { get; set; }                 public string Title { get; set; }    }

View发现和ActionResult执行

MVC默认的系统比较弱，当controller和view比较多的时候一个文件下面内容会非常多，我这里做了一个模块化处理.

using System.Web.Mvc;  namespace Coralcode.Mvc.ViewEngines {   public class ThemesRazorViewEngine : RazorViewEngine   {     public ThemesRazorViewEngine()     {       this.AreaViewLocationFormats = new string[3]       {         "~/Themes/{2}/{1}/{0}.cshtml",         "~/Themes/Shared/{0}.cshtml",         "~/Themes/{2}/Shared/{0}.cshtml"       };       this.AreaMasterLocationFormats = new string[1]       {         "~/Themes/Shared/{0}.cshtml"       };       this.AreaPartialViewLocationFormats = new string[4]       {         "~/Themes/{2}/{1}/{0}.cshtml",         "~/Themes/{2}/Shared/{0}.cshtml",         "~/Themes/Shared/{0}.cshtml",         "~/Themes/Shared/Control/{0}.cshtml"       };       this.ViewLocationFormats = new string[2]       {         "~/Themes/{1}/{0}.cshtml",         "~/Themes/Shared/{0}.cshtml"       };       this.MasterLocationFormats = new string[1]       {         "~/Themes/Shared/{0}.cshtml"       };       this.PartialViewLocationFormats = new string[2]       {         "~/Themes/{1}/{0}.cshtml",         "~/Themes/Shared/{0}.cshtml"       };     }      public override ViewEngineResult FindView(ControllerContext controllerContext, string viewName, string masterName, bool useCache)     {       if (controllerContext.RouteData.Values.ContainsKey("area") && !controllerContext.RouteData.DataTokens.ContainsKey("area"))         controllerContext.RouteData.DataTokens.Add("area", controllerContext.RouteData.Values["area"]);       return base.FindView(controllerContext, viewName, masterName, useCache);     }   }

项目目录结构如下图

这样子发布后的目录非常的干净，如图：

JsonResult执行和MetaData(模型元数据提供机制)

这部分在Controller设计那一节有详细说明，请往前一步参考

总结

•  大家一定要看看MVC源代码，
•  脑袋里要能把MVC执行流程串起来
•  主体设计已经讲完了，源代码整理中，工作比较忙，见谅，
•  喜欢请关注，有问题请留言，头疼得一笔，睡觉，晚安