如何使参数可选？(How to make an argument optional?)

如何使参数可选？(How to make an argument optional?)

在代码模块（命名功能区）中

Sub Form1Show(control As IRibbonControl) ' this is custom ribbon Form1.Show ' works End Sub

在ThisWorkbook模块中：

Private Sub Workbook_Open() Call Form1.Show ' error: argument not optional End Sub

有人可以解释一下吗？

In a code Module (named ribbon)

Sub Form1Show(control As IRibbonControl) ' this is custom ribbon Form1.Show ' works End Sub

In ThisWorkbook module:

Private Sub Workbook_Open() Call Form1.Show ' error: argument not optional End Sub

Can somebody explain this?

最满意答案

将参数声明为可选; 否则，它是必需的。

Sub Form1Show(Optional control As IRibbonControl)

Declare the parameter as optional; otherwise, it is required.

Sub Form1Show(Optional control As IRibbonControl)