VBA:在用户窗体上使用 WithEvents [英] VBA: Using WithEvents on UserForms

问题描述

我有一个 Word 用户表单，其中包含 60 多个不同类型的控件.我想在每次触发 control_change 事件并更改表单提交按钮的启用状态时评估表单.但是，我真的不想在更改事件处理程序上编写和维护 60.

I have a Word userform with 60+ controls of varying types. I would like to evaluate the form every time a control_change event is triggered and change the enabled state of the form's submit button. However, I really don't want to write and maintain 60 on change event handlers.

推荐答案

您可以创建一个事件接收器类，该类将包含特定类型的所有控件的事件处理代码.

You can create an event-sink class that will contain the event-handling code for all of your controls of a particular type.

例如，创建一个名为 TextBoxEventHandler 的类，如下所示:

For example, create the a class called TextBoxEventHandler as follows:

Private WithEvents m_oTextBox as TextBox

Public Property Set TextBox(ByVal oTextBox as TextBox)
    Set m_oTextBox = oTextBox
End Property

Private Sub m_oTextBox_Change()
    ' Do something
End Sub

现在您需要创建 &为表单上适当类型的每个控件连接该类的实例:

Now you need to create & hook up an instance of that class for each control of the appropriate type on your form:

Private m_oCollectionOfEventHandlers As Collection

Private Sub UserForm_Initialise()

    Set m_oCollectionOfEventHandlers = New Collection

    Dim oControl As Control
    For Each oControl In Me.Controls

        If TypeName(oControl) = "TextBox" Then

            Dim oEventHandler As TextBoxEventHandler
            Set oEventHandler = New TextBoxEventHandler

            Set oEventHandler.TextBox = oControl

            m_oCollectionOfEventHandlers.Add oEventHandler

        End If

    Next oControl

End Sub

请注意，您需要将事件处理程序实例添加到集合中的原因只是为了确保它们保持被引用，因此在您完成它们之前不会被垃圾收集器丢弃.

Note that the reason you need to add the event handler instances to a collection is simply to ensure that they remain referenced and thus don't get discarded by the garbage collector before you're finished with them.

显然，这种技术可以扩展到处理其他类型的控制.您可以为每种类型使用单独的事件处理程序类，也可以使用单个类，该类为您需要处理的每种控件类型提供一个成员变量(以及相关联的属性和事件处理程序).

Clearly this technique can be extended to deal with other types of control. You could either have separate event handler classes for each type, or you could use a single class that has a member variable (and associated property & event handler) for each of the control types you need to handle.

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