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

That won't produce the expected results b/c TryParse returns a bool rather than int. The easiest thing to do is create a function that returns an int.

private int parseNote(string note) 
{   
  int num;   
  if (!Int32.TryParse(note, out num)) 
  {
    num = int.MaxValue; // or int.MinValue - however it should show up in sort   
  }

  return num; 
}

call that function from your sort

Documenti = Documenti
    .OrderBy(o => parseNote(o.Note))
    .ToList();

you could do it inline too, but, i think a separate method makes the code more readable. i'm sure the compiler will inline it, if it's an optimization.