[求助]这段代码如何自定义为函数?

linjiandan

Select Case Range("a1").Value

    Case "一月"

        Range("d1") = b1 - c1

    Case "二月"

        Range("d1") = b1 + c1

    Case "三月"

        Range("d1") = b1 * c1

    Case "四月"

        Range("d1") = b1 / c1

End Select

晓月清风

Function selcase(VA1)

'其中VA1可以是引用单元格，也可以是字符串值，如“二月”

Application.Volatile

Select Case VA1

    Case "一月"

        selcase = [b1] - [c1]

    Case "二月"

        selcase = [b1] + [c1]

    Case "三月"

        selcase = [b1] * [c1]

    Case "四月"

        selcase = [b1] / [c1]

    Case Else

        selcase = Evaluate("Na()")

'如果VA1的值不在CASE中，则返回错误：#N/A

End Select

End Function