Variant in C# ?

[d00ape]

I’m coding in C# and I am working with a COM object that I earlier in C++ made this call:

COleVariant varBeforeEnd(DISP_E_MEMBERNOTFOUND, VT_ERROR);
hresult = pTemp->Add(knownObject, &varBeforeEnd );

How do I make the call in C#?

The IDE in VisualStudio say that the Add(…) function should have parameters like this:

Add(KownObject, ref object);

Any tip what to do with the second parameter? I’ve tried to block some primitive types like int and bool to an object, but I only get exceptions…

All tips are welcomed!

 

[misterstick]

first guess, create generic type Nullable<type> and cast that to object.

private Function()
{
 Add(KownObject, (object)(new Nullable<object>(obj)));
}

mr s. <

 

[d00ape]

hmmmm... never usen the Nullable type.

the compiler don't like casting the:

ref object

with:

(object)(new Nullable<object>(obj))

 

[misterstick]

perhaps that should be

private Function()
{
 Add(KownObject, ref (object)(new Nullable<object>(obj)));
}

what error are you getting?


mr s. <

 

[d00ape]

object obj = new object();
temp.Add(known, ref (object)(new Nullable<object>(obj)));



----------------------------------------------------
Error 1 The type 'object' must be a non-nullable value type in order to use it as parameter 'T' in the generic type or method 'System.Nullable<T>'
----------------------------------------------------

and

----------------------------------------------------
Error 2 Cannot convert type 'object?' to 'object'
----------------------------------------------------

 

[misterstick]

error 1 suggests you're using a reference type anyway.

you would only need to use Nullable for value types (int, double, etc).


mr s. <

 

[d00ape]

Got the solution!!

Object obj = System.Reflection.Missing.Value;
temp.Add(known, ref obj);

...easy as that!