Phone Number Validator Class

Below sample class validates phone number for counties USA, UK and Netherland. You can add the validations for other countries to the class.

public class PhoneValidator {

static IDictionary<string, Regex> countryRegex =
new Dictionary<string, Regex>() {
{ "USA", new Regex("^[2-9]\\d{2}-\\d{3}-\\d{4}quot;)},
{ "UK", new
Regex("(^1300\\d{6}$)|(^1800|1900|1902\\d{6}$)|(^0[2|3|7|8]{1}[0-
9]{8}$)|(^13\\d{4}$)|(^04\\d{2,3}\\d{6}$)")},
{ "Netherlands", new Regex("(^\\+[0-9]{2}|^\\+[0-
9]{2}\\(0\\)|^\\(\\+[0-9]{2}\\)\\(0\\)|^00[0-9]{2}|^0)([0-9]{9}$|[0-9\\-
\\s]{10}$)")},
};

public static bool IsValidNumber(string phoneNumber, string country) {
if (country != null && countryRegex.ContainsKey(country))
return countryRegex[country].IsMatch(phoneNumber);
else
return false;
}

public static IEnumerable<string> Countries {
get {
return countryRegex.Keys;
}
}
}

Using the class:

string ContactPhone="465 567 56";
string Country="USA";

if (!PhoneValidator.IsValidNumber(ContactPhone, Country))

{

  //Validation Message

}