VB 将二进制转化为八进制

Function erTo8(ByVal su As String) As String
'2进制转换为8进制
If IsNumeric(su) Then
For i = 1 To Len(su)
If Val(Mid(su, i, 1)) > 1 Then
erTo8 = "数据错误!"
Exit Function
End If
Next
Do
st = Format(Right(su, 3), "000")
erTo8 = Val(Right(st, 1)) + 2 * Val(Mid(st, 2, 1)) + 4 * Val(Left(st, 1)) & erTo8

If Len(su) >= 3 Then su = Left(su, Len(su) - 3) Else su = ""
Loop Until Len(su) = 0
Else
erTo8 = "数据错误!"
End If

End Function