Question

I want to set property via .InvokeMember but I can not do this when casting is required,

public Class A{
  private B? _bb;
  public B? Bb{
    get{return _bb;}
    set {_bb=value;}
  }
}


public struct B {
  public B(int i){}
  public static implicit operator B(int p)
        {   B q = new B(p);
            return q;
        }
}

when I set it via Simple Code,it works.

A myA=new A();
myA.Bb=12;

but when I try to set it via InvokeMember,it does not work with casting,it just work for direct type.

this code works

A myA=new A();
myA.GetType().InvokeMember("Bb", 
   BindingFlags.SetProperty, null,myA, new object[] { new B(12) });

but the next line , gives error and says that it can not find property “Bb”

A myA=new A();
myA.GetType().InvokeMember("Bb", 
   BindingFlags.SetProperty, null,myA, new object[] { 12});

I have to use it by the last way,how should I have to do it ?

Answer 1

This won’t even compile. B is a reference type, thus you cannot use it as a generic argument for the Nullable<T> class:

// Impossible
private B? _bb;

This being said, assuming you fix your code and declare B as a value type (using a struct for example), the problem is that Reflection doesn’t use implicit conversion operators.

You may take a look at the following thread for one possible solution.

Another possibility is to invoke the op_Implicit static method emitted by the compiler to convert the integer into an instance of B:

A myA = new A();
var op_Implicit = typeof(B).GetMethod("op_Implicit");
B myB = (B)op_Implicit.Invoke(null, new object[] { 12 });
myA.GetType().InvokeMember("Bb", BindingFlags.SetProperty, null, myA, new object[] { myB });