(inheritance) problem with generic

  • Thread starter Thread starter Lloyd Dupont
  • Start date Start date
L

Lloyd Dupont

I try to test the interface implemented by a generic with the simple test
below.
What puzzle me is that all 4 test return false!
Any idea why is that and how to find the IList interface from the type?

-------------
using System;
using System.Collections;
using System.Collections.Generic;

// csc /nologo Class1.cs && Class1
public class Class1
{
public static void Main()
{
List<string> ls = new List<string>();
if(ls is IList)
{
Console.WriteLine("is IList(1): " +
ls.GetType().IsSubclassOf(typeof(IList)));
Console.WriteLine("is IList(2): " +
ls.GetType().IsAssignableFrom(typeof(IList)));
Console.WriteLine("is IList(3): " +
ls.GetType().IsInstanceOfType(typeof(IList)));
Console.WriteLine("is IList(4): " +
ls.GetType().IsDefined(typeof(IList), true));
}
}
}
 
Have you tried "Console.WriteLine(ls is IList)"?

If ls is castable to IList, the result of using "is" operator will be "true"
 
obviously you haven't looked at my example....

yep what you worte (and I wrote it too), works very well.
however when you have a Type object, it's a bit more difficult with generic.

Anyway I solved it and posted the solution
 
Console.WriteLine("is IList(2): " +
ls.GetType().IsAssignableFrom(typeof(IList)));
Click to expand...

You're using it the wrong way around, try

Console.WriteLine("is IList(2): " +
typeof(IList).IsAssignableFrom(ls.GetType()));



Mattias
 
ooh...
aheum, indeed.....
thanks!

Mattias Sjögren said:
You're using it the wrong way around, try

Console.WriteLine("is IList(2): " +
typeof(IList).IsAssignableFrom(ls.GetType()));



Mattias
Click to expand...
 
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