Question

I am wanting to validate user input on a text box by only allowing (white space, letter, or digit, ‘-‘ and ‘_’). I was wondering if someone could help me with that regexp? I found this SO question, but i am trying it and it is not working.

Here is what i am using:

if (!System.Text.RegularExpressions.Regex.IsMatch(NameTextBox.Text, "/^([a-zA-Z])([a-zA-Z0-9_ -])$/"))

Thanks.

EDIT – New approach.

I actually decided to go with this instead of regex, any reason why i should not?

if (!NameTextBox.Text.All(c=>Char.IsLetterOrDigit(c) || c==' ' || c=='_' || c=='-'))

Reference for the above code.

Answer 1

I think this is what you want for your regex: @"^[\w\s-]{1,80}$"

^       match start of string
\w      will match any [A-Za-z0-9_]
\s      will match any whitespace
-       will match the - character
{1,80}  requires between 1 and 80 characters
$       match end of string

If by whitespace, you mean you want to match just space (and not tab let’s say), switch it to:

@"^[\w -]{1,80}$"