将十六进制转化为二进制C程序

' 用途：将十六进制转化为二进制
' 输入：Hex(十六进制数)
' 输入数据类型：String
' 输出：HEX_to_BIN(二进制数)
' 输出数据类型：String
' 输入的最大数为2147483647个字符
Public Function HEX_to_BIN(ByVal Hex As String) As String
    Dim i As Long
    Dim B As String
   
    Hex = UCase(Hex)
    For i = 1 To Len(Hex)
        Select Case Mid(Hex, i, 1)
            Case "0": B = B & "0000"
            Case "1": B = B & "0001"
            Case "2": B = B & "0010"
            Case "3": B = B & "0011"
            Case "4": B = B & "0100"
            Case "5": B = B & "0101"
            Case "6": B = B & "0110"
            Case "7": B = B & "0111"
            Case "8": B = B & "1000"
            Case "9": B = B & "1001"
            Case "A": B = B & "1010"
            Case "B": B = B & "1011"
            Case "C": B = B & "1100"
            Case "D": B = B & "1101"
            Case "E": B = B & "1110"
            Case "F": B = B & "1111"
        End Select
    Next i
    While Left(B, 1) = "0"
        B = Right(B, Len(B) - 1)
    Wend
    HEX_to_BIN = B
End Function