How to determine base interface???

Suppose the following:

class MyContainer : System.Collections.CollectionBase
{
//...
}

(where CollectionBase implements IList, ICollection)

How do I determine if a type (such as MyContainer) derives from IList?

System.Type type = typeof(MyContainer);

type is IList -> false

type.IsSubclassOf(typeof(IList)) -> false

type.IsAssignableFrom(typeof(IList)) -> false

etc., all tests return false.

So, what I need is a way to determine if a particular type derives from IList, no matter how far up the hierarchy it is.

Thanks

How do I determine if a type (such as MyContainer) derives from IList?

Hi!

how about that ? is that too much overkill ?
?!
//***
IList lst = type as IList;
if (lst != null)
Console.WriteLine("type does implement IList");
//***

J. Jones wrote:

How do I determine if a type (such as MyContainer) derives from IList?

Use the C# is statement:
if (MyContainer is IList) {
// Handle IList implementation
}

J. Jones wrote:

How do I determine if a type (such as MyContainer) derives from IList?

Use the C# is statement:
if (MyContainer is IList) {
// Handle IList implementation
}

Anders Norås
http://dotnetjunkies.com/weblog/anoras/

J. Jones wrote:

How do I determine if a type (such as MyContainer) derives from IList?

Use the C# is statement:
if (MyContainer is IList) {
// Handle IList implementation
}

how about that ? is that too much overkill ?
//***
IList lst = type as IList;
if (lst != null)
Console.WriteLine("type does implement IList");
//***

type.IsAssignableFrom(typeof(IList)) -> false

Suppose the following:

class MyContainer : System.Collections.CollectionBase
{
//...
}

(where CollectionBase implements IList, ICollection)

How do I determine if a type (such as MyContainer) derives from IList?

System.Type type = typeof(MyContainer);

type is IList -> false

type.IsSubclassOf(typeof(IList)) -> false

type.IsAssignableFrom(typeof(IList)) -> false

etc., all tests return false.

So, what I need is a way to determine if a particular type derives from IList,
no matter how far up the hierarchy it is.

No go. I need to test a System.Type variable, so your code becomes

Console.WriteLine("MyContainer implements IEnumerable : {0}",
typeof(MyContainer).GetInterface("System.Collectio ns.IEnumerable") != null)

BaseCollection *does not* implements the Ilist :

J. Jones <jj@networld.com> wrote:

Suppose the following:

class MyContainer : System.Collections.CollectionBase
{
//...
}

(where CollectionBase implements IList, ICollection)

How do I determine if a type (such as MyContainer) derives from IList?

System.Type type = typeof(MyContainer);

type is IList -> false

type.IsSubclassOf(typeof(IList)) -> false

type.IsAssignableFrom(typeof(IList)) -> false

etc., all tests return false.

So, what I need is a way to determine if a particular type derives from IList,
no matter how far up the hierarchy it is.

You're using IsAssignableFrom the wrong way round - it's very easy to
do, and I always have to look up the documentation to check it.
Basically, you want

typeof(IList).IsAssignableFrom(type)