How MVC avoids the value that a controller method receives cannot be converted to a parameter type

Suppose the controller method parameter type is int:

 Public ActionResult getsth (int  ID)        {            return  Content (ID. ToString ());        }

And the view passes over the string:

@Html. ActionLink (" get ","getsth",new {ID ="hello"})

It will then report a mistake similar to the following:

For non-nullable types of method "System.Web.Mvc.ActionResult getsth (Int32)" in "MvcApplication3.Controllers.HomeController" System.Int32 "parameter" id ", the parameter dictionary contains a null item. An optional parameter must be a reference type, a nullable type, or a declaration as an optional parameter.
Parameter name: Parameters

Workaround one: Allow parameters to be null

 Public ActionResult getsth (int? ID)        {            return  Content (ID. ToString ());        }

Workaround Two: Assign default values to parameters

 public  actionresult getsth (int  id=< Span style= "COLOR: #800080" >1  ) { return   Content (ID.        ToString ()); }