Question

NET. I have created a regex validator to check for special characters means I donot want any special characters in username. The following is the code

Regex objAlphaPattern = new Regex(@"[a-zA-Z0-9_@.-]");
            bool sts = objAlphaPattern.IsMatch(username);

If I provide username as $%^&asghf then the validator gives as invalid data format which is the result I want but If I provide a data s23_@.-^&()%^$# then my validator should block the data but my validator allows the data which is wrong

So how to not allow any special characters except a-z A-A 0-9 _ @ .-

Thanks
Sunil Kumar Sahoo

Answer 1

There’s a few things wrong with your expression. First you don’t have the start string character ^ and end string character $ at the beginning and end of your expression meaning that it only has to find a match somewhere within your string.

Second, you’re only looking for one character currently. To force a match of all the characters you’ll need to use * Here’s what it should be:

Regex objAlphaPattern = new Regex(@"^[a-zA-Z0-9_@.-]*$");
bool sts = objAlphaPattern.IsMatch(username);