Can I use a TryParse inside Linq Comparable?

Question

A sort of:

Documenti = Documenti
    .OrderBy(o => string.IsNullOrEmpty(o.Note))
    .ThenBy(o => Int32.TryParse(o.Note))
    .ToList();

Answer 1

You can actually put much more complex logic in the lambda expression:

List Documenti = new List() {
        new Doc(""),
        new Doc("1"),
        new Doc("-4"),
        new Doc(null) };

Documenti = Documenti.OrderBy(o => string.IsNullOrEmpty(o.Note)).ThenBy(o => 
{
    int result;
    if (Int32.TryParse(o.Note, out result))
    {
        return result;
    } else {
        return Int32.MaxValue;
    }
}).ToList();

foreach (var item in Documenti)
{
    Console.WriteLine(item.Note ?? "null");
    // Order returned: -4, 1, , null
}

Remember, o => Int32.TryParse(...) is just a shorthand for creating a delegate that just takes in o as a parameter and returns Int32.TryParse(...). You can make it do whatever you want as long as it still is a syntacticly correct method with the correct signature (ex, all code paths return an int)