VB.NET Kredi Kartı Kontrolü

[/COLOR][CODE]Public Enum CreditCardTypes        Invalid = -1
        VISA
        MASTERCARD
        DISCOVER
        AMEX
    End Enum


    Private Shared CreditCardPatterns As New List(Of String) _
                 (New String() { _
                 "^(4\d{12})|(4\d{15})$", _
                 "^5[1-5]\d{14}$", _
                 "(^(6011)\d{12}$)|(^(65)\d{14}$)", _
                 "^3[47]\d{13}$"})


    Private Shared _cardNumber As String


    Public Shared Function Validate(ByVal cardNumber As String) As CreditCardTypes
        Dim CardType As CreditCardTypes = CreditCardTypes.Invalid
        _cardNumber = Regex.Replace(cardNumber, "[^\d]", String.Empty)
        CardType = CType(CreditCardPatterns.FindIndex(AddressOf FindPattern), CreditCardTypes)
        If CardType = CreditCardTypes.Invalid Then
            _cardNumber = String.Empty
            Return CreditCardTypes.Invalid
        End If
        Dim Digits As Char() = _cardNumber.ToCharArray
        _cardNumber = String.Empty
        Dim Digit As Integer
        Dim Sum As Integer = 0
        Dim Alt As Boolean = False
        Array.Reverse(Digits)
        For Each Value As Char In Digits
            Digit = Integer.Parse(Value)
            If Alt Then
                Digit *= 2
                If Digit > 9 Then
                    Digit -= 9
                End If
            End If
            Sum += Digit
            Alt = Not Alt
        Next
        If Sum Mod 10 = 0 Then
            Return CardType
        Else
            Return CreditCardTypes.Invalid
        End If
    End Function


    Private Shared Function FindPattern(ByVal value As String) As Boolean
        If Regex.IsMatch(_cardNumber, value) Then
            Return True
        Else
            Return False
        End If
    End Function[/CODE]






		Dim CardType As Satis.CreditCardTypes = Satis.Validate(TxtKredino.Text)
        If CardType = Me.CreditCardTypes.Invalid Then
            LblKredino.Text = "GEÇERSİZ KREDİ KARTI NUMARASI"
            LblKredino.ForeColor = Color.Red
            pickart.Visible = False
        Else
            LblKredino.Text = String.Concat("GEÇERLİ ", [Enum].GetName(GetType(Satis.CreditCardTypes), CardType), " KREDİ KARTI NUMARASI")
            LblKredino.ForeColor = Color.Green

 End If[COLOR=Silver]