public async void CheckLoginCorrectness()
{
if (Login != null)
{
string loginPattern = @"^[a-zA-Z_][a-zA-Z0-9_\-\.]{1,255}$";
Login = Login.Trim();
if (Login.Length < 2)
{
LoginError = "Login should be at least 2 charachters long";
LoginIsCorrect = false;
}
else if (char.IsDigit(Login[0]))
{
LoginError = "Login can only start with a letter or underscore";
LoginIsCorrect = false;
}
else if (Login.Length > 255)
{
LoginError = "Login should be no longer than 255 characters";
LoginIsCorrect = false;
}
else if (!Regex.IsMatch(Login, loginPattern, RegexOptions.CultureInvariant))
{
LoginError = "Login should contain only latin letters, numbers and _ . -";
LoginIsCorrect = false;
}
else if (!await serverWorker.TaskCheckLogin(Login))
{
LoginError = "This login is already used";
LoginIsCorrect = false;
}
else
{
LoginError = " ";
LoginIsCorrect = true;
}
}
else
{
LoginError = "Login cannot be empty";
LoginIsCorrect = false;
}
}
