IP Address in a MaskedTextBox?

Question

How can I use a MaskedTextBox to prevent the user from entering an invalid IP address? (I want it to behave just like the Windows one).

Answer 1

It is better to use REGEX to validate user input. Here's an example:

         string pattern = @"\b(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\b";

        string ip1 = "192.168.0.1";
        string ip2 = "302.0.0.1";

        Regex.IsMatch(ip1, pattern); // returns true
        Regex.IsMatch(ip2, pattern); // returns false