我需要多次调用特定的一段代码,因此我想要使用可选参数。 我可以写出如下代码:
Public Sub main()
strA = "A"
'Calling the function
CalculateMe (strA)
End Sub
Public Sub CalculateMe(strA As String)
Set rs = DB.OpenRecordset("tbl_A")
rs.MoveFirst
Do Until rs.EOF
If rs.Fields(0) = strA Then
dblA = rs.fields(2).Value
End If
rs.MoveNext
Loop
End Sub
我该如何更改函数以支持超过1个可选参数?
类似于:
Public Sub main()
strA = "A"
strB = "B"
'Calling the function
CalculateMe (strA, strB)
more code
End Sub
Public Sub CalculateMe(Optional strA As String, Optional strB as String)
Set rs = DB.OpenRecordset("tbl_A")
rs.MoveFirst
Do Until rs.EOF
If rs.Fields(0).Value = strA And rs.Fields(1).Value = strB Then
dblA = rs.Fields(2).Value
End If
rs.MoveNext
Loop
End Sub
在Pankaj Jaju的建议下,我成功地将其更改为以下内容:
Public Sub main()
strA = "A"
strB = "B"
'Calling the function
dblA = CalculateMe (strA, strB)
End Sub
Public Function CalculateMe(Optional ByVal strA As String, Optional ByVal strB as String)
Set rs = DB.OpenRecordset("tbl_A")
rs.MoveFirst
Do Until rs.EOF
If rs.Fields(0).Value = strA And rs.Fields(1).Value = strB Then
dblA = rs.Fields(2).Value
End If
rs.MoveNext
Loop
End Sub
现在,我该如何清除可选参数的值? 这对于某些计算很必要。类似这样的东西:Set strA = Nothing