主题：请大师指教！谢谢！

大师您好!我有一个列是"表A"的"amkf"列 我想要输入分数:  如5 1/2, 显示 5.5,或输入1/2  显示 0.5, 代码如下:

If e.DataCol.Name = "amkf" Then
    If e.DataRow.IsNull("amkf") Then
        e.DataRow("amkf") = Nothing
    Else
        Dim n  = e.DataRow("amkf")
        If n.Length = 1 Then
            e.DataRow("amkf") = n
        Else
            If n.Length = 2 Then
                e.DataRow("amkf") = n
            Else
                Dim d As String = n
                Dim s() As String = d.split(" ")
                If s.Length = 1 Then
                    Dim o() As String = d.split("/")
                    Dim m = (o(0)) / (o(1))
                    e.DataRow("amkf") = m
                Else
                    Dim a As String = (S(1))
                    Dim c() As String = a.split("/")
                    Dim f As Integer  = CInt(c(1))
                    Dim g As Integer  = CInt(c(0))
                    Dim h = (c(0)) / (c(1))
                    Dim j = (s(0))+h
                    e.DataRow("amkf") = j
                End If
            End If
        End If
    End If
End If

输入分数后提示:"调用的止标发生异常 

显示祥细信息:

.NET Framework 版本：2.0.50727.8745
Foxtable 版本：2017.3.2.1
错误所在事件：表，表A，DataColChanged
详细错误信息：
调用的目标发生了异常。
索引超出了数组界限。

请教大师如何修改代码?谢谢!!!