Why can I not use as-cast to convert `object` to an enum type?

Question

When you implement ICommand you have to implement the public void Execute(object parameters) method, which takes parameters of type object.

For my specific application I'm interested in how I can implement an ICommand which takes an enum as parameter.

In my command I implement Execute like this:

public void Execute(object parameter)
{
  if (parameter is null) throw new ArgumentNullException("parameter");
  State s = parameter as State;
  }

where State is my enum type defined as

public enum State
{
  NeutralState,
  MeasureCircleState,
  MeasureSphereState  
}

Unfortunately my IDE flags my code, specifically the line State s = parameter as State; as invalid.

What is wrong with my code?
Can I not convert my object parameter to my enum type State?

Answer 1

object parameter can be converted to enum:

public void Execute(object parameter)
{
    if (parameter is State s)
    {
       // do work;
    }
    else
    {
         throw new ArgumentException(nameof(parameter));
    }
}

you should also pass it correctly from XAML, e.g:

CommandParameter="{x:Static local:State.NeutralState}"

and not just CommandParameter="NeutralState", which will pass a string