MVC Controller different parameter signature for method

Question

MVC 5, .NET 4.5.1

In my base Controller class I have the following defined

    [AcceptVerbs(HttpVerbs.Get)]
    public virtual ActionResult Edit(long Id)
    {
    }

This has been fine up to now. However in the new controller class which descends from above I need to change the method signature to:

   [AcceptVerbs(HttpVerbs.Get)]
    public new ActionResult Edit(string Id)
    {
    }

Note that the parameter Id is now a string. However when the action is invoked on the descendant controller I get the following error:

The parameters dictionary contains a null entry for parameter 'Id' of non-nullable type 'System.Int64' for method 'System.Web.Mvc.ActionResult Edit(Int64)' in 'XXXX.Controllers.MlControllerGridView`2[MakersLane.Web.ViewModels.Login.LoginAddEditViewModel,XXXX.Web.ViewModels.Login.LoginAddEditViewModel]'. An optional parameter must be a reference type, a nullable type, or be declared as an optional parameter. Parameter name: parameters

So my question is how do I change the parameter Id to be of type string in my descendant controller and not access any base behaviour?

Why do you have that method in the base class to begin with? — jmcilhinney
Its historical and I cannot change it right at the minute. So I need to work around the issue — TheEdge

TheEdge TheEdge · Accepted Answer · 2015-02-18T05:34:56

I solved this by doing the using the [NonAction] attribute. This way the "long id" is "removed" and it correctly picks up the "string id" version. Not pretty, but it works.

    public ActionResult Edit(string Id)
    {
        return RedirectToAction("NotYetImplemented", "SystemManagement");
    }

    /// <summary>
    ///     To work around the base class requiredment that the Id be a long we override the
    ///     base class and mark this as not an action. Use the string version instead.
    /// </summary>
    /// <param name="Id"></param>
    /// <returns></returns>
    [NonAction]
    public override ActionResult Edit(long Id)
    {
        return RedirectToAction("NotYetImplemented", "SystemManagement");
    }

MVC Controller different parameter signature for method

1 Answers