public async void CheckEmailCorrectness()
{
if (Email != null && Email != "")
{
string emailPattern = @"^(?("")(""[^""]+?""@)|(([0-9a-zA-Z]((\.(?!\.))|[-!#\$%&'\*\+/=\?\^`\{\}\|~\w])*)(?<=[0-9a-zA-Z])@))" +
@"(?(\[)(\[(\d{1,3}\.){3}\d{1,3}\])|(([0-9a-z][-\w]*[0-9a-z]*\.)+[a-z0-9]{2,17}))$";
if (Email.Length > 255)
{
EmailError = "Email should be no longer than 255 characters";
EmailIsCorrect = false;
}
else if (!Regex.IsMatch(Email, emailPattern, RegexOptions.CultureInvariant))
{
EmailError = "Enter a valid email address";
EmailIsCorrect = false;
}
else if (!await serverWorker.TaskCheckEmail(Email))
{
EmailError = "This email is already used";
EmailIsCorrect = false;
}
else
{
EmailError = " ";
EmailIsCorrect = true;
}
}
else
{
EmailError = "Please, enter your email";
EmailIsCorrect = false;
}
}