Can you overload controller methods in ASP.NET MVC?

Question

I\'m curious to see if you can overload controller methods in ASP.NET MVC. Whenever I try, I get the error below. The two methods accept different arguments. Is this some

Answer 1

There is only one public signature allowed for each controller method. If you try to overload it, it will compile, but you're getting the run-time error you've experienced.

If you're not willing to use different verbs (like the [HttpGet] and [HttpPost] attributes) to differentiate overloaded methods (which will work), or change the routing, then what remains is that you can either provide another method with a different name, or you can dispatch inside of the existing method. Here's how I did it:

I once came into a situation where I had to maintain backwards compatibility. The original method expected two parameters, but the new one had only one. Overloading the way I expected did not work because MVC didn't find the entry point any more.

To solve that, I did the following:

1. Changed the 2 overloaded action methods from public to private

2. Created one new public method which contained "just" 2 string parameters. That one acted as a dispatcher, i.e.:

   public ActionResult DoSomething(string param1, string param2)
   {
       if (string.IsNullOrEmpty(param2))
       {
           return DoSomething(ProductName: param1);
       }
       else
       {
           int oldId = int.Parse(param1);
           return DoSomething(OldParam: param1, OldId: oldId);
       }
   }
   
   
   private ActionResult DoSomething(string OldParam, int OldId)
   {
       // some code here
       return Json(result);
   }
   
   
   private ActionResult DoSomething(string ProductName)
   {
       // some code here
       return Json(result);
   }
   

Of course, this is a hack and should be refactored later. But for the time being, it worked for me.

You can also create a dispatcher like:

public ActionResult DoSomething(string action, string param1, string param2)
{
    switch (action)
    {
        case "update":
            return UpdateAction(param1, param2);
        case "remove":
            return DeleteAction(param1);
    }
}

You can see, that UpdateAction needs 2 parameters, while DeleteAction just needs one.