private bool Validate()
{
try
{
if (CardNumber.Length < 12 || CardNumber.Length > 19)
{
return(false);
}
var IIN = CardNumber.Substring(0, 6);
CardType = eCardType.Unknown;
if (IIN.StartsWith("34") || IIN.StartsWith("37"))
{
CardType = eCardType.AmericanExpress;
}
else if (IIN.StartsWith("4"))
{
if (IIN.StartsWith("4026") || IIN.StartsWith("417500") || IIN.StartsWith("4405") || IIN.StartsWith("4508") ||
IIN.StartsWith("4844") || IIN.StartsWith("4913") || IIN.StartsWith("4917"))
{
CardType = eCardType.VisaElectron;
}
else
{
CardType = eCardType.Visa;
}
}
else if (IIN.StartsWith("51") || IIN.StartsWith("52") || IIN.StartsWith("53") || IIN.StartsWith("54") ||
IIN.StartsWith("55"))
{
CardType = eCardType.MasterCard;
}
else if (IIN.StartsWith("6011") || IIN.StartsWith("644") || IIN.StartsWith("65"))
{
CardType = eCardType.Discover;
}
else if (IIN.StartsWith("36") || IIN.StartsWith("38") || IIN.StartsWith("39"))
{
CardType = eCardType.DinersClubInternational;
}
else if (IIN.StartsWith("3"))
{
var jcbCheck = Convert.ToInt32(IIN.Substring(0, 4));
if (jcbCheck >= 3528 && jcbCheck <= 3589)
{
CardType = eCardType.JCB;
}
else
{
var dinersCheck = Convert.ToInt32(IIN.Substring(0, 3));
if (dinersCheck < 306)
{
CardType = eCardType.DinersClubCarteBlanche;
}
else if (dinersCheck == 309)
{
CardType = eCardType.DinersClubInternational;
}
else
{
return(false);
}
}
}
else
{
return(false);
}
//// 1. Starting with the check digit double the value of every other digit
//// 2. If doubling of a number results in a two digits number, add up
/// the digits to get a single digit number. This will results in eight single digit numbers
//// 3. Get the sum of the digits
int sumOfDigits = CardNumber.Where((e) => e >= '0' && e <= '9')
.Reverse()
.Select((e, i) => ((int)e - 48) * (i % 2 == 0 ? 1 : 2))
.Sum((e) => e / 10 + e % 10);
//// If the final sum is divisible by 10, then the credit card number
// is valid. If it is not divisible by 10, the number is invalid.
return(sumOfDigits % 10 == 0);
}
catch
{
return(false);
}
}