Should be easy...
class Base{}
class Foo:Base{}
public bool Bar(Type t){
// return ???
// NB: shouldn't know anything about Foo, just Base
}
Assert.True(Bar(typeof(IEnumerable<Foo>));
Assert.False(Bar(typeof(IEnumerable<Base>));
Assert.False(Bar(typeof(string));
Assert.False(Bar(typeof(Foo));
Just to answer question why 2nd one should be false (actually - it does not matter, cause Bar argument will never be IEnumerable<Base>
).
I'm trying to write FluentNhibernate auto mapping convention which maps my class enumerations to integers. I successfully did that already, but things went down when I wanted to map IEnumerable<EnumerationChild>
(in my case - User.Roles).
public class EnumerationConvention:IUserTypeConvention{
private static readonly Type OpenType=typeof(EnumerationType<>);
public void Apply(IPropertyInstance instance){
//this is borked atm, must implement ienumerable case
var closedType=OpenType.MakeGenericType(instance.Property.PropertyType);
instance.CustomType(closedType);
}
public void Accept(IAcceptanceCriteria<IPropertyInspector> criteria){
criteria.Expect(
x=>typeof(Enumeration).IsAssignableFrom(x.Property.PropertyType) ||
typeof(IEnumerable<Enumeration>)
.IsAssignableFrom(x.Property.PropertyType));
}
}
You can use Type.IsAssignableFrom(Type)
. However, your question isn't really clear - you're specifying one type, but you need two... which type is Bar
meant to be checking t
against?
Note that the answer will change between .NET 3.5 and .NET 4, due to generic covariance - in .NET 3.5, for example, a List<Foo>
is not assignable to IEnumerable<Base>
, but in .NET 4 it is.
EDIT: Here's a program which prints True, True, False, False. I'm not sure why you expected the second one to be false:
using System;
using System.Collections;
using System.Collections.Generic;
class Base{}
class Foo:Base{}
class Test
{
static bool Bar(Type t)
{
return typeof(IEnumerable<Base>).IsAssignableFrom(t);
}
static void Main()
{
Console.WriteLine(Bar(typeof(IEnumerable<Foo>)));
Console.WriteLine(Bar(typeof(IEnumerable<Base>)));
Console.WriteLine(Bar(typeof(string)));
Console.WriteLine(Bar(typeof(Foo)));
}
}
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