Regular expressions in C# for file name validation

Question

What is a good regular expression that can validate a text string to make sure it is a valid Windows filename? (AKA not have \\/:*?\"<>| characters).

Answer 1

Path.GetInvalidFileNameChars - Is not a good way. Try this:

if(@"C:\A.txt".IndexOfAny(System.IO.Path.GetInvalidFileNameChars()) != -1)
{
  MessageBox.Show("The filename is invalid");
  return;
}