VBA：WithEvents难题

本文介绍了VBA：WithEvents难题的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我有一个UserForm， xForm ，正在一个类模块中被实例化（让我们说 TestClass ）为：

I have a UserForm, xForm, that is being instantiated in a class module (let's say TestClass) as:

'TestClass Dim Form as New xForm Private WithEvents EvForm as MSForms.UserForm Set EvForm = Form

在xForm本身的类模块中，我有一些必须在表单关闭时执行的代码，只有当表单实际关闭时： / p>

At the class module of the xForm itself I have some code that must be executed on Form Closing, ONLY if the form actually closes:

'xForm class module Private Sub UserForm_QueryClose(Cancel As Integer, CloseMode As Integer) 'Do some cleanup, otherwise the app would hang 'If not closing, don't cleanup anything, otherwise the app would hang End Sub

QueryClose事件也在TestClass中处理，可以避免关闭窗体：

The QueryClose event is also treated in TestClass, and could avoid the form from closing:

'TestClass Private Sub EvForm_QueryClose(Cancel As Integer, CloseMode As Integer) 'Verify if closing is allowed based on User Control values Cancel = Not ClosingIsAllowed '<-- Pseudocode on the right side of "=" End Sub

如何在xForm类模块中测试Cancel = True，在TestClass中设置？ 让我们重新表述：如果TestClass中的Cancel被设置为True，我不能在xForm类模块中执行清除代码。如何才能实现？

How can I test for Cancel = True, set in TestClass, in the xForm class module? Let's rephrase it: If Cancel is set to True in TestClass, I must not do the cleanup code in the xForm class module. How can I accomplish that?

到目前为止，我已经考虑在xForm类（My_QueryClose？）中实现另一个事件，并将其提交到QueryClose事件。在代码后面我将只处理My_QueryClose事件，所以完全控制发生了什么。这是一个可行/更好的方法吗？

Until now, I have thought off of implementing another event in the xForm class (My_QueryClose?) and raise it on the QueryClose event. Outside the Code Behind Form I would deal only with the My_QueryClose event, so taking full control over what is happening. Is this a viable/better approach?

推荐答案

解决另一个事件的工作

代码不如我所期望的那样，尽管它不像我希望的那样整齐。

The code bellow do what I was expecting, although it is not as neat as I wish it could be.

在 UserForm1 代码：

'***** UserForm1 Public Event MyQueryClose(ByRef Cancel As Integer, ByRef CloseMode As Integer, ByRef Status As String) Private Sub UserForm_QueryClose(Cancel As Integer, CloseMode As Integer) Dim Status As String Cancel = True Status = "QueryClose" Debug.Print "Entered QueryClose" Debug.Print "Cancel = " & Cancel Debug.Print "Status = " & Status Debug.Print "Just before raising MyQueryClose" RaiseEvent MyQueryClose(Cancel, CloseMode, Status) Debug.Print "Just got back from MyQueryClose" Debug.Print "Cancel = " & Cancel Debug.Print "Status = " & Status End Sub

在 Class1 代码中： p>

In the Class1 code:

'***** Class1 Dim UserForm As New UserForm1 Private WithEvents UF As UserForm1 Sub DoIt() Set UF = UserForm UserForm.Show End Sub Private Sub UF_MyQueryClose(Cancel As Integer, CloseMode As Integer, Status As String) Debug.Print "Just entered MyQueryClose" Cancel = False Status = "MY QueryClose" End Sub

在基本模块中，测试Class：

In a basic module, to test the Class:

'***** Basic module Sub TestClass() Dim C As New Class1 C.DoIt End Sub

这是最终结果（调试窗口）：

And here's the end result (debug window):

TestClass Entered QueryClose Cancel = -1 Status = QueryClose Just before raising MyQueryClose Just entered MyQueryClose Just got back from MyQueryClose Cancel = 0 Status = MY QueryClose