发生异常:对于“Web.Controllers.HomeController”中方法“System.Web.Mvc.ActionResult List(Int32)”的不可以为 null 的类型“System.Int32”的参数“id”,参数字典包含一个 null 项。可选参数必须为引用类型、可以为 null 的类型或声明为可选参数。 Parameter name: parameters at System.Web.Mvc.ActionDescriptor.ExtractParameterFromDictionary(ParameterInfo parameterInfo, IDictionary`2 parameters, MethodInfo methodInfo) at System.Web.Mvc.ReflectedActionDescriptor.<>c__DisplayClass1.b__0(ParameterInfo parameterInfo) at System.Linq.Enumerable.WhereSelectArrayIterator`2.MoveNext() at System.Linq.Buffer`1..ctor(IEnumerable`1 source) at System.Linq.Enumerable.ToArray[TSource](IEnumerable`1 source) at System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters) at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass42.b__41() at System.Web.Mvc.Async.AsyncResultWrapper.<>c__DisplayClass8`1.b__7(IAsyncResult _) at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResult`1.End() at System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult) at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass37.<>c__DisplayClass39.b__33() at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass4f.b__49() at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass37.b__36(IAsyncResult asyncResult) at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResult`1.End() at System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethodWithFilters(IAsyncResult asyncResult) at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass25.<>c__DisplayClass2a.b__20() at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass25.b__22(IAsyncResult asyncResult)