Check if an object is a type object

[Fredrik Strandberg]

Hi!

I receive an object as a System.Object argument to a method. I need to
check if the object is a Type object or not (that is, not a specific
type, but if the object is a type object in general). How can I do
this? Is there a way of checking if my object inherits from the
System.Type class?

sub myMethod(obj as Object)

if ("obj is a type object")

...do my stuff...

I could not find any solution in any thread in the google groups. I
only find threads about how to determine the Type of an object, but I
need to determine if my object is a Type object!

As far as i understand, I am not able to use the Type.IsInstance OfType
method since the Type class is abstract, i.e.

Type typeObj
typeObj.IsInsta nceOfType(GetTy pe(obj))

does not work.

Thank you for your time!

/Fredrik

[AlanT]

Tried that first, unfortunately, it didn't work

If I have

VB.Net
----------
Private Sub fx(ByVal obj As Object)
Trace.WriteLine (obj.GetType.To String() & " " & (obj.GetType Is
GetType(Type)). ToString)
End Sub

C#
----
private void fx(Object obj) {
Trace.WriteLine (obj.ToString() + " " + (obj.GetType() ==
typeof(System.T ype)).ToString( ));
}

then

VB.Net
----------
fx(17)
fx(17.GetType() )

C#
------
fx(17);
fx(17.GetType() );
gives

System.Int32 False
System.RuntimeT ype False

Apparently, RuntimeType does not inherit from Type.
Alan.

%^&$% Cross-posted questions. Doubles my typing. ;)

[AlanT]

Update to previous reply

TypeOf (obj) //VB worked

where

typeof (System.Type) // C#

didn't.

thanks,
Alan.

What did I say about $%^^ cross postings ;)

[Mattias Sjögren]

> Trace.WriteLine (obj.GetType.To String() & " " & (obj.GetType Is

GetType(Type)) .ToString)
I suggested you use the TypeOf .. Is operator. 'Is' by itself does
something different, it compares object identity.

Apparently, RuntimeType does not inherit from Type.

It sure does.
Mattias

--
Mattias Sjögren [C# MVP] mattias @ mvps.org
http://www.msjogren.net/dotnet/ | http://www.dotnetinterop.com
Please reply only to the newsgroup.

[Fredrik Strandberg]

Thank you for all your help, google groups i amazing and I become happy
when there are people in the world willing to help each other!

Alan T and Larry Lard, both your descriptions described my problem
perfectly. Of all the suggestions, the following worked for me:

if ( obj.GetType().T oString() = "System.Runtime Type" )
if ( thing.GetType() .IsSubclassOf( GetType (Type) ) )
if TypeOf obj Is Type

Phill W - about overloading, that was my first instinct. However, what
I am trying to do is build a wrapper class using Reflection to be able
to access private members of classes for testing purposes. I would like
to be able to invoke a private method with the same method call no
matter if the method is static or an instance method, and the objects
used with the wrapper class may be all known and unknown objects/types
in the universe =) :

providing an object for an instance method:

runMethod(myObj ect, "nameOfInstance Method")

and providing the class type for a static method:

runMethod(myTyp e, "nameOfStaticMe thod")

However if I would overload the runMethod as in:

runMethod(ByVal obj As Object)
runMethod(ByVal t As Type)

I think the first method would always be used, since System.Type
inherits from Object. Please correct me if I'm wrong =)

Anyway, the solutions provided by you fine folks work fine, so again -
thank you very much!

Have a brilliant day!

/Fredrik