Removing all whitespace lines from a multi-line string efficiently

Question

In C# what\'s the best way to remove blank lines i.e., lines that contain only whitespace from a string? I\'m happy to use a Regex if that\'s the best solution.

EDIT

Answer 1

Im not sure is it efficient but =)

  List strList = myString.Split(new string[] { "\n" }, StringSplitOptions.None).ToList();
  myString = string.Join("\n", strList.Where(s => !string.IsNullOrWhiteSpace(s)).Distinct().ToList());