Problem sorting lists using delegates

Question

I am trying to sort a list using delegates but I am getting a signature match error. The compiler says I cannot convert from an 'anonymous method'

List<MyType> myList = GetMyList();
myList.Sort( delegate (MyType t1, MyType t2) { return (t1.ID < t2.ID); } );

What am I missing?

Here are some references I found and they do it the same way.

Developer Fusion Reference

Microsoft Reference

Answer 1

I think you want:

myList.Sort( delegate (MyType t1, MyType t2) 
    { return (t1.ID.CompareTo(t2.ID)); } 
);

To sort you need something other than "true/false", you need to know if its equal to, greater than, or less than.

Answer 2

The Sort doesn't take a binary predicate, it takes a Comparison<T> delegate which returns an int not a bool.

The return values are 0 for when the items are equal, <0 for when the first item is less than the second, and >0 for when the first item is greater than the second.