B、当选择完合适的Action后，接着就是 ModelBinder（默认是System.Web.Mvc.DefaultModelBinder），它会从http请求的参数中提取数据并实现类型转换，数据校验（例如是否必填，数据格式等）以及是否自动装配到action方法的参数中System.Web.Mvc.DefaultModelBinder
protected virtual IDictionary<string, object> GetParameterValues(ControllerContext controllerContext, ActionDescriptor actionDescriptor) { Dictionary<string, object> dictionary = new Dictionary<string, object>(StringComparer.OrdinalIgnoreCase); ParameterDescriptor[] parameters = actionDescriptor.GetParameters(); for (int i = 0; i < parameters.Length; i++) { ParameterDescriptor parameterDescriptor = parameters[i]; dictionary[parameterDescriptor.ParameterName] = this.GetParameterValue(controllerContext, parameterDescriptor); } return dictionary; } protected virtual object GetParameterValue(ControllerContext controllerContext, ParameterDescriptor parameterDescriptor) { Type parameterType = parameterDescriptor.ParameterType; IModelBinder arg_92_0 = this.GetModelBinder(parameterDescriptor); IValueProvider valueProvider = controllerContext.Controller.ValueProvider; string modelName = parameterDescriptor.BindingInfo.Prefix ?? parameterDescriptor.ParameterName; Predicate<string> propertyFilter = ControllerActionInvoker.GetPropertyFilter(parameterDescriptor); ModelBindingContext bindingContext = new ModelBindingContext { FallbackToEmptyPrefix = parameterDescriptor.BindingInfo.Prefix == null, ModelMetadata = ModelMetadataProviders.Current.GetMetadataForType(null, parameterType), ModelName = modelName, ModelState = controllerContext.Controller.ViewData.ModelState, PropertyFilter = propertyFilter, ValueProvider = valueProvider }; return arg_92_0.BindModel(controllerContext, bindingContext) ?? parameterDescriptor.DefaultValue; }
C、Authentication Filter是mvc5中新增的一个Filter，它会先于authorization filter执行，目的是对访问用户的认证。在MVC5之前，认证和授权都是通过authorization filter来实现的，但现在这2个操作就分开来了，各自管各自喽。
AuthenticationContext authenticationContext = this.InvokeAuthenticationFilters(controllerContext, filters.AuthenticationFilters, actionDescriptor); if (authenticationContext.Result != null) { AuthenticationChallengeContext authenticationChallengeContext = this.InvokeAuthenticationFiltersChallenge(controllerContext, filters.AuthenticationFilters, actionDescriptor, authenticationContext.Result); this.InvokeActionResult(controllerContext, authenticationChallengeContext.Result ?? authenticationContext.Result); }
D、Action filters有2个方法OnActionExecuting和OnActionExecuted分别在action执行前后执行。我们也可以通过实现IActionFilter接口来实现你个性化的过滤机制
protected virtual ActionExecutedContext InvokeActionMethodWithFilters(ControllerContext controllerContext, IList<IActionFilter> filters, ActionDescriptor actionDescriptor, IDictionary<string, object> parameters) { ActionExecutingContext preContext = new ActionExecutingContext(controllerContext, actionDescriptor, parameters); Func<ActionExecutedContext> seed = () => new ActionExecutedContext(controllerContext, actionDescriptor, false, null) { Result = this.InvokeActionMethod(controllerContext, actionDescriptor, parameters) }; return filters.Reverse<IActionFilter>().Aggregate(seed, (Func<ActionExecutedContext> next, IActionFilter filter) => () => ControllerActionInvoker.InvokeActionMethodFilter(filter, preContext, next))(); }
E、接下来就是执行我们平时在Action方法中写的代码了（根据请求相应结果）
protected virtual ActionResult InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary<string, object> parameters) { object actionReturnValue = actionDescriptor.Execute(controllerContext, parameters); return this.CreateActionResult(controllerContext, actionDescriptor, actionReturnValue); }
（4）、ActionResult 执行模块。
A、在 ActionResult 执行前后，仍然会有一个filter（IResultFilter），同样的，通过实现 IResultFilter 接口你可以定制自己的过滤逻辑。