"How can I efficiently sort a list of custom objects in C# based on multiple properties?

Question

I have a list of custom objects in C#, and I need to sort this list based on multiple properties of the objects. Each object has several properties, and I want to sort the list first by PropertyA in ascending order and then by PropertyB in descending order. What's the most efficient and clean way to achieve this in C#?

Thank you!

I've tried using List.Sort() and OrderBy() with LINQ, but I'm having trouble sorting by multiple properties simultaneously. Can someone provide a code example or point me in the right direction to achieve this sorting efficiently?

Answer 1

With LINQ you can use OrderBy(Descending) followed by ThenBy(Descending).

Enumerable.ThenByDescending:

Performs a subsequent ordering of the elements in a sequence in descending order.

The following:

var sorted = myCollection
    .OrderBy(i => i.PropertyA)
    .ThenByDescending(i => i.PropertyB)
    .ToList();

Will sort the collection by PropertyA (ascending) then by PropertyB in descending order and put results into a new list.