活动处理抽象课程

Question

基本上，我有一个自定义的儿童表格类，该课程将传递给父母。在“自定义子”表单中，我有一个继承DEVEXPRESS用户控制类的“ NuderInherit”类声明。

这样做的原因是，我有许多从该基类得出的用户控件，并且子表格可以具有这些控件中任何一个的实例，并且不在乎哪个。唯一的要求是，子形式可以以相同的方式处理每种类型的控制类型的事件。

一些浇水的代码片段（不幸的是仍然很久）：

'''Inherited Class
Public Class ChildControlInheritedClass
    'A Button Click event that starts the chain of events.
    Private Sub btnMoveDocker_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnConvertToTab.Click
        OnMoveToDocker(Me, New ChildGridMoveArgs(Me))
    End Sub
End Class

'''Base Class
Public MustInherit Class ChildControlBaseClass
    Inherits DevExpress.XtraEditors.XtraUserControl
    Public Class ChildGridMoveArgs
        Inherits System.EventArgs
        Public Sub New(ByVal _ChildControl As ChildControlInheritedClass)
            ChildControl = _ChildControl
        End Sub
        Public ChildControl As ChildControlInheritedClass
    End Class
    Public Event MoveToDocker(ByVal sender As Object, ByVal e As ChildGridMoveArgs)
    Protected Overridable Sub OnMoveToDocker(ByVal sender As Object, ByVal e As ChildGridMoveArgs)
        '''Once this RaiseEvent is fired, nothing happens. The child form is oblivious.
        RaiseEvent MoveToDocker(sender, e)
    End Sub
End Class

'''Child Form Class
Public Class ChildForm
    Private WithEvents cgChild As ChildControlBaseClass
    Public Property ChildGrid() As ChildControlInheritedClass
        Get
            Return cgChild
        End Get
        Set(ByVal value As ChildControlInheritedClass)
            RemoveHandler cgChild.MoveToDocker, AddressOf cgChild_MoveToDocker
            cgChild.Dispose()
            cgChild = Nothing
            cgChild = value
            AddHandler cgChild.MoveToDocker, AddressOf cgChild_MoveToDocker
        End Set
    End Property
    Public Event MoveToDocker(ByVal sender As Object, ByVal e As ChildControlInheritedClass.ChildGridMoveArgs)
    Public Sub cgChild_MoveToDocker(ByVal sender As Object, ByVal e As ChildControlInheritedClass.ChildGridMoveArgs)
        RaiseEvent MoveToDocker(sender, New ChildControlInheritedClass.ChildGridMoveArgs(cgChild))
    End Sub
End Class

Public Class frmMain
    Private Sub OpenNewWindow()
        Dim frm As New ChildForm
        Dim chld As New ChildControlInheritedClass
        frm.ChildGrid = chld
        frm.Show()
    End Sub
End Class

简而言之，这就是我如何制作孩子的形式以及一切都应该如何工作。但是，当我按下继承的儿童控制中的按钮时，该事件只能达到基类，并且永远不会将raiseevent穿越到应该处理事件的孩子形式中。

我甚至在这里的球场吗？

谢谢阅读！

Answer 1

您忘了使用Addhandler或Handles标识符添加事件句柄。请参见下面使用句柄CGCHILD.MovetOdocker标识符。

Public Class ChildForm
    ...
    Public Sub cgChild_MoveToDocker(ByVal sender As Object, ByVal e As ChildControlInheritedClass.ChildGridMoveArgs) Handles cgChild.MoveToDocker
        RaiseEvent MoveToDocker(sender, New ChildControlInheritedClass.ChildGridMoveArgs(cgChild))
    End Sub
End Class