kala-tamin Cannot call action method 'System.Web.Mvc.PartialViewResult Foo[T](T)' on controller 'Controller' because the action method is a generic method
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Cannot call action method 'System.Web.Mvc.PartialViewResult Foo[T](T)' on controller 'Controller' because the action method is a generic method

Cannot call action method 'System.Web.Mvc.PartialViewResult FooT' on controller 'Controller' because the action method is a generic method

<% Html.RenderAction("Foo", model = Model}); %> 

Is there a workaround for this limitation on ASP MVC 2? I would really prefer to use a generic. The workaround that I have come up with is to change the model type to be an object. It works, but is not preferred:

    public PartialViewResult Foo<T>(T model) where T : class     {       // do stuff     } 

ASP.net/MVC file upload with URL rewrite enabled


Empty asp.net Resources Cache, provided by SQLResourceProvider
The code this throws this is inside the default ActionDescriptor:. Sending data to server (ASP.NET MVC) with Ajax(jQuery) through JSON
    internal static string VerifyActionMethodIsCallable(MethodInfo methodInfo) {         // i can't call instance methods where the 'this' parameter is a type another than ControllerBase         if (!methodInfo.IsStatic && !typeof(ControllerBase).IsAssignableFrom(methodInfo.ReflectedType)) {             return String.Format(CultureInfo.CurrentUICulture, MvcResources.ReflectedActionDescriptor_CannotCallInstanceMethodOnNonControllerType,                 methodInfo, methodInfo.ReflectedType.FullName);         }          // i can't call methods with open generic type parameters         if (methodInfo.ContainsGenericParameters) {             return String.Format(CultureInfo.CurrentUICulture, MvcResources.ReflectedActionDescriptor_CannotCallOpenGenericMethods,                 methodInfo, methodInfo.ReflectedType.FullName);         }          // i can't call methods with ref/out parameters         ParameterInfo[] parameterInfos = methodInfo.GetParameters();         foreach (ParameterInfo parameterInfo in parameterInfos) {             if (parameterInfo.IsOut || parameterInfo.ParameterType.IsByRef) {                 return String.Format(CultureInfo.CurrentUICulture, MvcResources.ReflectedActionDescriptor_CannotCallMethodsWithOutOrRefParameters,                     methodInfo, methodInfo.ReflectedType.FullName, parameterInfo);             }         }          // i must call this method         return null;     } 
Because the code is calling "methodInfo.ContainsGenericParameters" I don't think there is a way to override this behavior without creating your own ActionDescriptor. How to get the Url for urlAction helper class? From glancing at the source code this seems non-trivial.. calling a jquery function from asp.net mvc action Ananother option is to make your controller class generic and create a custom generic controller factory. How to register javascript in ASP.NET MVC action? I have any experimental code this creates a generic controller. Can I deny access to a Wordpress directory with MVC 2? Its hacky although its just a personal experiment.. Why won't my MVC project work after publishing it?
public class GenericControllerFactory : DefaultControllerFactory {     protected override Type GetControllerType(System.Web.Routing.RequestContext requestContext, string controllerName)     {         //the generic type parameter doesn't matter here         if (controllerName.EndsWith("Co"))//assuming i don't have any another generic controllers here             return typeof(GenericController<>);          return base.GetControllerType(requestContext, controllerName);          throw new InvalidOperationException("Generic Factory wasn't able to resolve the controller type");     }      protected override IController GetControllerInstance(System.Web.Routing.RequestContext requestContext, Type controllerType)     {         //are i asking for the generic controller?         if (requestContext.RouteData.Values.ContainsKey("modelType"))         {             string typeName = requestContext.RouteData.Values["modelType"].ToString();             //magic time             return GetGenericControllerInstance(typeName, requestContext);         }          if (!typeof(IController).IsAssignableFrom(controllerType))             throw new ArgumentException(string.Format("Type requested is not a controller: {0}",controllerType.Name),"controllerType");          return base.GetControllerInstance(requestContext, controllerType);     }       /// <summary>     /// Returns the a generic IController tied to the typeName requested.       /// Since i only have a single generic controller the type is hardcoded for now     /// </summary>     /// <param name="typeName"></param>     /// <returns></returns>     private IController GetGenericControllerInstance(string typeName, RequestContext requestContext)     {         var actionName = requestContext.RouteData.Values["action"];          //try and resolve a custom view model          Type actionModelType = Type.GetType("Brainnom.Web.Models." + typeName + actionName + "ViewModel, Brainnom.Web", false, true) ??              Type.GetType("Brainnom.Web.Models." + typeName + ",Brainnom.Web", false, true);          Type controllerType = typeof(GenericController<>).MakeGenericType(actionModelType);          var controllerBase = Activator.CreateInstance(controllerType, new object[0] {}) as IController;          return controllerBase;     } } 


Six year later, with MVC5 (and MVC6) in town, I ran into this same problem. I'm building my site with MVC5 so I must safely assume it's not yet supported out of the box. I landed here in search of solution. Well, I eventually found a way to fix it without hacking into the controller or its factory, especially for the reason this I only needed this feature in just a few places. . The approach: modifying slightly the Command Pattern (which I was already using in my code anyway).. For this problem, you start by defining the interface.
public interface IMyActionProcessor {     PartialViewResult Process<T>(T theModel); } 
and the corresponding implementation:.
public sealed class MyActionProcessor : IMyActionProcessor {     // Your IoC container. I had it explicitly mapped just like any another      // registration to cause constructor injection. Using SimpleInjector, it will be      // <code>Container.Register(typeof(IServiceProvider), () => Container);</code>     private IServiceProvider _serviceProvider;     public MyActionProcessor(IServiceProvider serviceProvider)      {         _serviceProvider = serviceProvider;     }     public PartialViewResult Process<T>(T theModel)     {         var handlerType =             typeof(IMyActionHandler<>).MakeGenericType(theModel.GetType());          dynamic handler = _serviceProvider.GetService(handlerType);          return handler.Handle((dynamic)theModel);     } } 
The handler (userd in the code above) will look like this:.
public interface IMyActionHandler<T> where T : class {     PartialViewResult Execute(T theModel); } 
With the above in place, all you now have to did is provide implementation(s) for the handler based on the specifics of your class T. Something like this:.
public class ModelClassHandler : IMyActionHandler<ModelClass> {     public PartialViewResult Execute(ModelClass theModel);     {         // Do Stuff here and return a PartialViewResult instance     } } 
With all the above in place, you must now simply did this in your controller:.
var processor = YourServiceLocator.GetService<IMyActionProcessor>(); var model = new ModelClass { /* Supply parameters */ };  var partialViewResult = processor.Process(model); 
I know it's an extra level of indirection although it worked excellently. In my case, I went on extend the handler and processor so this they must return anything I want, not just PartialViewResult. . I'll be interested in seeing a simpler quick fix to this, if one exist. I guess it's not common to have this kind of problem using MVC.. PS: Any good IoC container should be able to register open generics by scanning through assemblies. Thus, once configured appropriately, you did not need to explicitly register the implementations for the handler interface..

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