list sorting in c#

(Assuming you don't have LINQ available to you, which makes this trivial.)

If you look in MiscUtil, you'll find two useful classes: ProjectionComparer and LinkedComparer (IIRC).

ProjectionComparer basically implements the LINQ "order by" concept - you specify how to convert a source element to a key value, and the comparer will order by those key values.

LinkedComparer takes two comparers and returns a new comparer which uses the "primary" comparer first, and the "secondary" comparer if values are equal with respect to the primary one.

Create two projection comparers (one for each property) and then a linked comparer with the two of them, then pass that to List<T>.Sort. Let me know if you need a full code sample, but it would be something like (using C# 3):

var comparer = new LinkedComparer<Foo>
     (ProjectionComparer<Foo>.Create(x => x.FirstProperty),
      ProjectionComparer<Foo>.Create(x => x.SecondProperty));

(In C# 2 you could use anonymous methods, they'd just be a bit more long-winded.)

Sounds like you want to use LINQ's orderby and thenby syntax.

A List has a Sort method which takes a Comparision delegate as an argument. There are also overloads where you can pass in your own comparer.

So, you can write a class which implements IComparer. Then, in the implementation of this class, you write the code where you compare the 2 objects on the properties you want.