十进制转化为十六进制2

Private Sub Command1_Click()
   Dim a As Integer
   Dim b As Integer
   Dim s As String
   Dim yushu As Byte
   a = 1230: b = 16
   While a <> 0
       yushu = a Mod b
       s = f(yushu) & s
       a = a \ b
    Wend
    Print s
End Sub
Private Function f(yushu As Byte) As String
    If yushu <= 9 Then
        f = yushu
    Else
        Select Case yushu
            Case 10, 11, 12, 13, 14, 15
                f = Chr(yushu + 55)
        End Select
    End If
End Function