Vb.net 需要新的描述算法吗

校验位计算

字母表中的数字和字母是赋值的。0-9等于0-9。A-Z是10-35，空格是36

示例字符串： CA5B9AJ1564

计算：
C=12
A=10
5=5
B=11
9=9
A=10
J=19
1=1
5=5
6=6
4=4

每个值按从36到1的降序相乘，如下所示：
36*12=432
35*10=350
34*5=170
33*11=363
32*9=288
31*10=310
30*19=570
29*1=29
28*5=140
27*6=162
26*4=104

=2918

2918然后除以37=78 r32
32的剩余部分从股息=37-32=
中减去 5是校验位

我需要帮助将上述算法转换为vb.net中的一系列嵌套循环或私有子循环。我想使用Mod运算符，因为我们公司现在使用的公式是3。我在Excel中手动运行了3个不同的字符串。
当前代码：（使用测试字符串关闭3）

Private函数CheckDigit37（ByVal字段字符串作为字符串）
将字符串值设置为整数
将索引设置为整数
将最后位置设置为整数
Dim CharIndex作为整数
作为字符串的Dim CharString
变暗值37一样长
使余数变长
Dim CheckDigitValue为整数
Dim CheckDigit As String=“”
如果FieldString=“”，则
返回错误
其他的
FieldString=FieldString.ToUpper
String36Value=RoundUp（FieldString.Length/36）
如果结束
对于PositionIndex=1到String36Value
如果FieldString.Length=36，则
LastPosition=36
ElseIf PositionIndexPrivate Function CheckDigit37(ByVal FieldString As String)
        Dim String36Value As Integer
        Dim PositionIndex As Integer
        Dim LastPosition As Integer
        Dim CharIndex As Integer
        Dim CharString As String
        Dim Value37 As Long
        Dim Remainder As Long
        Dim CheckDigitValue As Integer
        Dim CheckDigit As String = " "

        If FieldString = "" Then
            Return False
        Else
            FieldString = FieldString.ToUpper
            String36Value = RoundUp(FieldString.Length / 36)
        End If

        For PositionIndex = 1 To String36Value
            If FieldString.Length = 36 Then
                LastPosition = 36
            ElseIf PositionIndex < String36Value Then
                LastPosition = 36
            Else
                LastPosition = FieldString.Length - 36 * (PositionIndex - 1)
            End If

            For CharIndex = 1 To LastPosition
                CharString = Mid(FieldString, CharIndex + (PositionIndex - 1) * 36, 1)
                'If CharString = "" Then GoTo EndLoop
                Select Case CharString
                    Case 0
                        Value37 = Value37 + 0 * (37 - CharIndex)
                    Case 1
                        Value37 = Value37 + 1 * (37 - CharIndex)
                    Case 2
                        Value37 = Value37 + 2 * (37 - CharIndex)
                    Case 3
                        Value37 = Value37 + 3 * (37 - CharIndex)
                    Case 4
                        Value37 = Value37 + 4 * (37 - CharIndex)
                    Case 5
                        Value37 = Value37 + 5 * (37 - CharIndex)
                    Case 6
                        Value37 = Value37 + 6 * (37 - CharIndex)
                    Case 7
                        Value37 = Value37 + 7 * (37 - CharIndex)
                    Case 8
                        Value37 = Value37 + 8 * (37 - CharIndex)
                    Case 9
                        Value37 = Value37 + 9 * (37 - CharIndex)
                    Case "A"
                        Value37 = Value37 + 10 * (37 - CharIndex)
                    Case "B"
                        Value37 = Value37 + 11 * (37 - CharIndex)
                    Case "C"
                        Value37 = Value37 + 12 * (37 - CharIndex)
                    Case "D"
                        Value37 = Value37 + 13 * (37 - CharIndex)
                    Case "E"
                        Value37 = Value37 + 14 * (37 - CharIndex)
                    Case "F"
                        Value37 = Value37 + 15 * (37 - CharIndex)
                    Case "G"
                        Value37 = Value37 + 16 * (37 - CharIndex)
                    Case "H"
                        Value37 = Value37 + 17 * (37 - CharIndex)
                    Case "I"
                        Value37 = Value37 + 18 * (37 - CharIndex)
                    Case "J"
                        Value37 = Value37 + 19 * (37 - CharIndex)
                    Case "K"
                        Value37 = Value37 + 20 * (37 - CharIndex)
                    Case "L"
                        Value37 = Value37 + 21 * (37 - CharIndex)
                    Case "M"
                        Value37 = Value37 + 22 * (37 - CharIndex)
                    Case "N"
                        Value37 = Value37 + 23 * (37 - CharIndex)
                    Case "O"
                        Value37 = Value37 + 24 * (37 - CharIndex)
                    Case "P"
                        Value37 = Value37 + 25 * (37 - CharIndex)
                    Case "Q"
                        Value37 = Value37 + 26 * (37 - CharIndex)
                    Case "R"
                        Value37 = Value37 + 27 * (37 - CharIndex)
                    Case "S"
                        Value37 = Value37 + 28 * (37 - CharIndex)
                    Case "T"
                        Value37 = Value37 + 29 * (37 - CharIndex)
                    Case "U"
                        Value37 = Value37 + 30 * (37 - CharIndex)
                    Case "V"
                        Value37 = Value37 + 31 * (37 - CharIndex)
                    Case "W"
                        Value37 = Value37 + 32 * (37 - CharIndex)
                    Case "X"
                        Value37 = Value37 + 33 * (37 - CharIndex)
                    Case "Y"
                        Value37 = Value37 + 34 * (37 - CharIndex)
                    Case "Z"
                        Value37 = Value37 + 35 * (37 - CharIndex)
                    Case " "
                        Value37 = Value37 + 36 * (37 - CharIndex)
                    Case Else
                        Value37 = Value37 + 0 * (37 - CharIndex)
                End Select
            Next
        Next

        Remainder = Value37 - Int(Value37 / 37) * 37
        CheckDigitValue = 37 - Remainder

        Select Case CheckDigitValue
            Case 0
                CheckDigit = 0
            Case 1
                CheckDigit = 1
            Case 2
                CheckDigit = 2
            Case 3
                CheckDigit = 3
            Case 4
                CheckDigit = 4
            Case 5
                CheckDigit = 5
            Case 6
                CheckDigit = 6
            Case 7
                CheckDigit = 7
            Case 8
                CheckDigit = 8
            Case 9
                CheckDigit = 9
            Case "10"
                CheckDigit = "A"
            Case "11"
                CheckDigit = "B"
            Case "12"
                CheckDigit = "C"
            Case "13"
                CheckDigit = "D"
            Case "14"
                CheckDigit = "E"
            Case "15"
                CheckDigit = "F"
            Case "16"
                CheckDigit = "G"
            Case "17"
                CheckDigit = "H"
            Case "18"
                CheckDigit = "I"
            Case "19"
                CheckDigit = "J"
            Case "20"
                CheckDigit = "K"
            Case "21"
                CheckDigit = "L"
            Case "22"
                CheckDigit = "M"
            Case "23"
                CheckDigit = "N"
            Case "24"
                CheckDigit = "O"
            Case "25"
                CheckDigit = "P"
            Case "26"
                CheckDigit = "Q"
            Case "27"
                CheckDigit = "R"
            Case "28"
                CheckDigit = "S"
            Case "29"
                CheckDigit = "T"
            Case "30"
                CheckDigit = "U"
            Case "31"
                CheckDigit = "V"
            Case "32"
                CheckDigit = "W"
            Case "33"
                CheckDigit = "X"
            Case "34"
                CheckDigit = "Y"
            Case "35"
                CheckDigit = "Z"
            Case "36"
                CheckDigit = " "
            Case "37"
                CheckDigit = "0"
        End Select

        Return CheckDigit
    End Function

Private Function CheckDigit37(ByVal FieldString As String) As String

    Dim CharIndex As Integer = 36
    Dim Value37 As Long
    Dim CheckDigitValue As Integer
    Dim CheckDigit As String = ""
    ' This will hold the character we're currently evaluating
    Dim C As Char

    FieldString = FieldString.ToUpper()

    For i As Integer = 0 To FieldString.Length - 1

        ' If CharIndex has reached 0 and we still have characters left,
        ' change it back to 36
        If (CharIndex = 0) Then
            CharIndex = 36
        End If

        ' Get the next character in the string
        C = FieldString(i)

        If (IsNumeric(C)) Then
            ' Subtract 48 from the ASCII value to get the algorithm value
            Value37 = Value37 + (CharIndex * (Asc(C) - 48))
        ElseIf (Asc(C) >= 65 AndAlso Asc(C) <= 90) Then
            ' Subtract 55 from the ASCII value to get the algorithm value
            Value37 = Value37 + (CharIndex * (Asc(C) - 55))
        ElseIf (Asc(C) = 32) Then
            ' We have a space (ASCII 32)
            Value37 = Value37 + (CharIndex * 36)
        End If

        ' Decrease the CharIndex by 1
        CharIndex = CharIndex - 1
    Next

    CheckDigitValue = 37 - (Value37 Mod 37)

    If (CheckDigitValue <= 9) Then
        ' We have a number
        CheckDigit = Chr(CheckDigitValue + 48)
    ElseIf (CheckDigitValue = 36) Then
        ' We have a space
        CheckDigit = Chr(32)
    Else
        ' We have A - Z
        CheckDigit = Chr(CheckDigitValue + 55)
    End If

    Return CheckDigit
End Function