The credit card validation through asp.net is used to check the content and validate the card numbers with matched value. The sample code to validate the credit card using asp.net is given below.
To validate Credit card:
public static bool IsCardNumberValid(string cardNumber)
{
int i, checkSum = 0;
// Compute checksum of every other digit starting from right-most digit
for (i = cardNumber.Length - 1; i >= 0; i -= 2)
checkSum += (cardNumber[i] - '0');
// Now take digits not included in first checksum, multiple by two,
// and compute checksum of resulting digits
for (i = cardNumber.Length - 2; i >= 0; i -= 2)
{
int val = ((cardNumber[i] - '0') * 2);
while (val > 0)
{
checkSum += (val % 10);
val /= 10;
}
}
// Number is valid if sum of both checksums MOD 10 equals 0
return ((checkSum % 10) == 0);
}
To remove non-digit characters:
public static string NormalizeCardNumber(string cardNumber)
{
if (cardNumber == null)
cardNumber = String.Empty;
StringBuilder sb = new StringBuilder();
foreach (char c in cardNumber)
{
if (Char.IsDigit(c))
sb.Append(c);
}
return sb.ToString();
}