Using lambda expression in place of IComparer argument

Question

Is it possible with C# to pass a lambda expression as an IComparer argument in a method call?

eg something like

var x = someIEnumerable.OrderBy(aClass e => e.someProperty,  (aClass x, aClass y) =>    x.someProperty > y.SomeProperty ?  1 : x.someProperty < y.SomeProperty ?  -1 : 0); 

I can't quite get this to compile so I'm guessing not, but it seems such an obvious synergy between lambdas and anonymous delegates that I feel I must be doing something foolishly wrong.

TIA

Answer 1

If you're on .NET 4.5, you can use the static method Comparer<aClass>.Create.

Documentation: Comparer<T>.Create Method .

Example:

var x = someIEnumerable.OrderBy(e => e.someProperty,      Comparer<aClass>.Create((x, y) => x.someProperty > y.SomeProperty ?  1 : x.someProperty < y.SomeProperty ?  -1 : 0)     ); 

Answer 2

As Jeppe points out, if you're on .NET 4.5, you can use the static method Comparer<T>.Create.

If not, this is an implementation that should be equivalent:

public class FunctionalComparer<T> : IComparer<T> {     private Func<T, T, int> comparer;     public FunctionalComparer(Func<T, T, int> comparer)     {         this.comparer = comparer;     }     public static IComparer<T> Create(Func<T, T, int> comparer)     {         return new FunctionalComparer<T>(comparer);     }     public int Compare(T x, T y)     {         return comparer(x, y);     } }