public static bool _IsValidAddressInt(string addr) { string valid = "1234567890."; bool ok = true; if (ok = (!string.IsNullOrEmpty(addr)) && addr.Contains(".") && addr.Split('.').Length == 4) { foreach (char chr in addr) { ok = valid.Contains(chr) ? ok : false; } foreach (string str in Formatters.Divide(addr)) { ok = _IsValidAddressNumber(str) ? ok : false; } } return(ok); }