Excel 如何忽略使用可选参数的代码？

我有一个sub，它接受一个必选参数和一个可选参数：

Sub selectRange(txtbox As MSForms.TextBox, Optional lbl As MSForms.Label)

我必须同时传递两个参数，否则会出错

考虑到sub包含直接引用可选参数（lbl）的行，该错误是可以理解的，如：

If Len(s) = 0 Then
    lbl.ForeColor = RGB(255, 0, 0)
    lbl.Font.Italic = True
    lbl.Caption = "{!this range doesn't contain values!}"
    Exit Sub
End If

可选参数在代码中的许多其他地方都有引用

---

我需要做哪些修改，以便selectRange可以在只传递所需参数的情况下运行？

您需要检查控件是否已传递，然后相应地处理它。比如说

Sub selectRange(txtbox As MSForms.TextBox, Optional lbl As MSForms.Label)
    '
    '~~> Rest of the code which has nothing to do with the label
    '

    '~~> For label, Check it is passed
    If Not lbl Is Nothing Then
        If Len(s) = 0 Then
            lbl.ForeColor = RGB(255, 0, 0)
            lbl.Font.Italic = True
            lbl.Caption = "{!this range doesn't contain values!}"
            Exit Sub
        End If
    End If
End Sub

下面是如何测试它的

Private Sub CommandButton1_Click()
    '<~~ This is will give the first message box
    selectRange TextBox1, Label1

    '<~~ This is will give the Second message box
    selectRange TextBox1
End Sub

Sub selectRange(txtbox As MSForms.TextBox, Optional lbl As MSForms.Label)
    '~~> For label, Check it is passed
    If Not lbl Is Nothing Then
        MsgBox "Label control is passed as a parameter"
    Else
        MsgBox "Label control is not passed as a parameter"
    End If
End Sub

Private子命令按钮1\u单击（）
'对于标签，请检查是否已通过
如果不是，那么lbl什么都不是
MsgBox“标签控件作为参数传递”
其他的
MsgBox“标签控件未作为参数传递”
如果结束
端接头

谢谢Siddharth Rout！我“分离”了lbl的代码，并按照您的演示对其进行了测试，现在它可以完美地工作：）