Delegate for an Action< ref T1, T2>

Question

I'm trying to create a delegate of a static method which takes a ref argument. Please don't ask why I'm doing such a cockamamie thing. It's all part of learning how .Net, C#, and reflection work and how to optimize it.

My code is:

    public struct DataRow     {          private double t;         static public void Cram_T(ref DataRow dr, double a_t)         {             dr.t = a_t;         }     }  ''''   Type myType = typeof(DataRow);   MethodInfo my_Cram_T_Method = myType.GetMethod("Cram_T");   var myCram_T_Delegate =           Delegate.CreateDelegate(typeof(Action<DataRow, Double>),                                        my_Cram_T_Method)                                   as Action<DataRow, Double>; 

This gives me a binding error because (I think) the generic action doesn't match the method.

Inspecting the value of Cram_T_Method in the watch window gives

{Void Cram_T(DataRow ByRef, Double)} 

I then tried using the ref keyword in the Action:

  var myCram_T_Delegate =           Delegate.CreateDelegate(typeof(Action<ref DataRow, Double>),                                           my_Cram_T_Method)                                   as Action<ref DataRow, Double>; 

But this won't compile. The C# compiler chokes at the token "ref".

What is the right way to create this delegate?

Answer 1

Create your own delegate type:

delegate void MyAction(ref DataRow dataRow, double doubleValue); 

And use MyAction in place of Action<ref DataRow, Double> -- which, as you've noted, doesn't compile.