Type.IsSubclassOf

[ME]

It appears that IsSubclassOf does not work. In the following example, why
does
typeof(IDerived ).IsSubclassOf( typeof(IRoot));
yeild False when the IDerived interface DOES in fact derive from IRoot? The
IsSubClassOf documentation states the following:

"Determines whether the current Type derives from the specified Type"

Wouldn't an interface be a Type? Basically I want to be able to look at an
interface TYPE and determine if it is related or derived from another
Interface TYPE.

Thanks,

Matt

public interface IRoot {}
public interface IDerived : IRoot {}
public class RootClass : IRoot {}
public class DerivedClass : RootClass {}
class IsSubclassTest
{
public static void Main()
{
RootClass root = new RootClass();
DerivedClass derived = new DerivedClass();
int [] intArray = new int [10];
Console.WriteLi ne("Is Array a derived class of int[]? {0}",
typeof(Array).I sSubclassOf(int Array.GetType() )); //False
Console.WriteLi ne("Is int [] a derived class of Array? {0}",
intArray.GetTyp e().IsSubclassO f(typeof(Array) )); //True
Console.WriteLi ne("Is IRoot a derived class of IDerived? {0}",
typeof(IRoot).I sSubclassOf(typ eof(IDerived))) ; //False
Console.WriteLi ne("Is IDerived a derived class of IRoot? {0}",
typeof(IDerived ).IsSubclassOf( typeof(IRoot))) ; //False???
Console.WriteLi ne("Is RootClass a derived class of DerivedClass? {0}",
root.GetType(). IsSubclassOf(de rived.GetType() )); //False
Console.WriteLi ne("Is DerivedClass a derived class of RootClass? {0}",
derived.GetType ().IsSubclassOf (root.GetType() )); //True
Console.Read();
}
}

[Sean Hederman]

Re: Type.IsSubclass Of

"ME" <trash.trash@co mcast.netREMOVE THIS> wrote in message
news:0I2dnZocj5 K7Kw3fRVn-hw@comcast.com. ..[color=blue]
> It appears that IsSubclassOf does not work. In the following example, why
> does
> typeof(IDerived ).IsSubclassOf( typeof(IRoot));
> yeild False when the IDerived interface DOES in fact derive from IRoot?
> The IsSubClassOf documentation states the following:
>
> "Determines whether the current Type derives from the specified Type"
>
> Wouldn't an interface be a Type? Basically I want to be able to look at
> an interface TYPE and determine if it is related or derived from another
> Interface TYPE.[/color]

Use typeof(IRoot).I sAssignableFrom (typeof(IDerive d)), since this determines
if two types can be used interchangeably . IsSubclass determines if a type
derives from another, but interfaces aren't really derived, rather
implemented.

typeof(CDerived ).IsSubclassOf( typeof(CRoot));

works as you expect.
[color=blue]
>
> Thanks,
>
> Matt
>
> public interface IRoot {}
> public interface IDerived : IRoot {}
> public class RootClass : IRoot {}
> public class DerivedClass : RootClass {}
> class IsSubclassTest
> {
> public static void Main()
> {
> RootClass root = new RootClass();
> DerivedClass derived = new DerivedClass();
> int [] intArray = new int [10];
> Console.WriteLi ne("Is Array a derived class of int[]? {0}",
> typeof(Array).I sSubclassOf(int Array.GetType() )); //False
> Console.WriteLi ne("Is int [] a derived class of Array? {0}",
> intArray.GetTyp e().IsSubclassO f(typeof(Array) )); //True
> Console.WriteLi ne("Is IRoot a derived class of IDerived? {0}",
> typeof(IRoot).I sSubclassOf(typ eof(IDerived))) ; //False
> Console.WriteLi ne("Is IDerived a derived class of IRoot? {0}",
> typeof(IDerived ).IsSubclassOf( typeof(IRoot))) ; //False???
> Console.WriteLi ne("Is RootClass a derived class of DerivedClass? {0}",
> root.GetType(). IsSubclassOf(de rived.GetType() )); //False
> Console.WriteLi ne("Is DerivedClass a derived class of RootClass? {0}",
> derived.GetType ().IsSubclassOf (root.GetType() )); //True
> Console.Read();
> }
> }
>[/color]

[ME]

Re: Type.IsSubclass Of

Thanks!

Matt
"Sean Hederman" <email.jpg@codi ngsanity.blogsp ot.com> wrote in message
news:d6qg8i$l16 $1@ctb-nnrp2.saix.net. ..[color=blue]
> "ME" <trash.trash@co mcast.netREMOVE THIS> wrote in message
> news:0I2dnZocj5 K7Kw3fRVn-hw@comcast.com. ..[color=green]
>> It appears that IsSubclassOf does not work. In the following example,
>> why does
>> typeof(IDerived ).IsSubclassOf( typeof(IRoot));
>> yeild False when the IDerived interface DOES in fact derive from IRoot?
>> The IsSubClassOf documentation states the following:
>>
>> "Determines whether the current Type derives from the specified Type"
>>
>> Wouldn't an interface be a Type? Basically I want to be able to look at
>> an interface TYPE and determine if it is related or derived from another
>> Interface TYPE.[/color]
>
> Use typeof(IRoot).I sAssignableFrom (typeof(IDerive d)), since this
> determines if two types can be used interchangeably . IsSubclass determines
> if a type derives from another, but interfaces aren't really derived,
> rather implemented.
>
> typeof(CDerived ).IsSubclassOf( typeof(CRoot));
>
> works as you expect.
>[color=green]
>>
>> Thanks,
>>
>> Matt
>>
>> public interface IRoot {}
>> public interface IDerived : IRoot {}
>> public class RootClass : IRoot {}
>> public class DerivedClass : RootClass {}
>> class IsSubclassTest
>> {
>> public static void Main()
>> {
>> RootClass root = new RootClass();
>> DerivedClass derived = new DerivedClass();
>> int [] intArray = new int [10];
>> Console.WriteLi ne("Is Array a derived class of int[]? {0}",
>> typeof(Array).I sSubclassOf(int Array.GetType() )); //False
>> Console.WriteLi ne("Is int [] a derived class of Array? {0}",
>> intArray.GetTyp e().IsSubclassO f(typeof(Array) )); //True
>> Console.WriteLi ne("Is IRoot a derived class of IDerived? {0}",
>> typeof(IRoot).I sSubclassOf(typ eof(IDerived))) ; //False
>> Console.WriteLi ne("Is IDerived a derived class of IRoot? {0}",
>> typeof(IDerived ).IsSubclassOf( typeof(IRoot))) ; //False???
>> Console.WriteLi ne("Is RootClass a derived class of DerivedClass? {0}",
>> root.GetType(). IsSubclassOf(de rived.GetType() )); //False
>> Console.WriteLi ne("Is DerivedClass a derived class of RootClass? {0}",
>> derived.GetType ().IsSubclassOf (root.GetType() )); //True
>> Console.Read();
>> }
>> }
>>[/color]
>
>[/color]