将十六进制转化为十进制的C程序

输入：Hex(十六进制数)
' 输入数据类型：String
' 输出：HEX_to_DEC(十进制数)
' 输出数据类型：Long
' 输入的最大数为7FFFFFFF,输出的最大数为2147483647
Public Function HEX_to_DEC(ByVal Hex As String) As Long
    Dim i As Long
    Dim B As Long
   
    Hex = UCase(Hex)
    For i = 1 To Len(Hex)
        Select Case Mid(Hex, Len(Hex) - i + 1, 1)
            Case "0": B = B + 16 ^ (i - 1) * 0
            Case "1": B = B + 16 ^ (i - 1) * 1
            Case "2": B = B + 16 ^ (i - 1) * 2
            Case "3": B = B + 16 ^ (i - 1) * 3
            Case "4": B = B + 16 ^ (i - 1) * 4
            Case "5": B = B + 16 ^ (i - 1) * 5
            Case "6": B = B + 16 ^ (i - 1) * 6
            Case "7": B = B + 16 ^ (i - 1) * 7
            Case "8": B = B + 16 ^ (i - 1) * 8
            Case "9": B = B + 16 ^ (i - 1) * 9
            Case "A": B = B + 16 ^ (i - 1) * 10
            Case "B": B = B + 16 ^ (i - 1) * 11
            Case "C": B = B + 16 ^ (i - 1) * 12
            Case "D": B = B + 16 ^ (i - 1) * 13
            Case "E": B = B + 16 ^ (i - 1) * 14
            Case "F": B = B + 16 ^ (i - 1) * 15
        End Select
    Next i
    HEX_to_DEC = B
End Function
' 用途：将十进制转化为十六进制
' 输入：Dec(十进制数)
' 输入数据类型：Long
' 输出：DEC_to_HEX(十六进制数)
' 输出数据类型：String
' 输入的最大数为2147483647,输出最大数为7FFFFFFF
Public Function DEC_to_HEX(Dec As Long) As String
    Dim a As String
    DEC_to_HEX = ""
    Do While Dec > 0
        a = CStr(Dec Mod 16)
        Select Case a
            Case "10": a = "A"
            Case "11": a = "B"
            Case "12": a = "C"
            Case "13": a = "D"
            Case "14": a = "E"
            Case "15": a = "F"
        End Select
        DEC_to_HEX = a & DEC_to_HEX
        Dec = Dec \ 16
    Loop
End Function