Resolution for C # Reflection setting field values invalid

Fieldinfo.setvalue's prototype is: void SetValue (object obj, object value)
When you pass a value type (structure is a value type), it is converted to object, that is, to boxing .
and SetValue will act on the boxed product, not the original structure.

The solution is to pack and remove the boxes yourself:

object boxedb = b;        // self-boxing in order to get the boxed product fi. SetValue (Boxedb, a);   //B = (b) boxedb;            // unpacking and getting the result of being SetValue. Console.WriteLine (b.a.x);

Resolution for C # Reflection setting field values invalid