VBA 函数 可选参数

Question

我多次调用特定的代码段，因此我想使用可选参数。我可以写这样的东西:

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

如何更改函数以保存 1 个以上可选参数？

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

按照 Pankaj Jaju 的建议，我设法将其更改为:

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，如何清除可选参数的值？我需要这个来进行一些计算。像这样的东西:

Set strA = Nothing

Answer 1

更改您的子项并添加 ByVal

Public Sub CalculateMe(Optional ByVal strA As String, Optional ByVal strB As String)