如何删除从类 VB.NET 的实例中添加的包装/自定义事件处理程序

Question

我需要创建多个 zkemkeeper.CZKEM 实例，以便一次创建与多个生物识别设备的活动 (250+) 连接以及事件。我创建了一个类来完成我想要的输出：

Public Class ZKEMEventsClass

    Public CZKEM2 As New zkemkeeper.CZKEM
    Public MyNewWrapperClass As MyWrapperClass

    Public Sub AddBioHandler(iDevice As String, iIP As String, iPort As Integer)
        If CZKEM2.Connect_Net(iIP, iPort) Then
            If CZKEM2.RegEvent(1, 65535) = True Then

                MyNewWrapperClass = New MyWrapperClass(iDevice, CZKEM2)

                AddHandler MyNewWrapperClass.AttEventWrapper, AddressOf LogRaised
                MsgBox("Handler successfully registered")
            Else
                MsgBox("Error Registering Events")
            End If
        Else
            MsgBox("Error Connecting to Device")
        End If

    End Sub


    Public Sub RemoveBioHandler(iDevice As String, CZKEM As zkemkeeper.CZKEM)
        >>> MyNewWrapperClass = New MyWrapperClass(iDevice, CZKEM)
        >>> RemoveHandler MyNewWrapperClass.AttEventWrapper, AddressOf LogRaised
    End Sub

    Public Sub LogRaised(ByVal SenderName As String, ByVal sEnrollNumber As String, ByVal iIsInValid As Integer, ByVal iAttState As Integer, ByVal iVerifyMethod As Integer, ByVal iYear As Integer, ByVal iMonth As Integer, ByVal iDay As Integer, ByVal iHour As Integer, ByVal iMinute As Integer, ByVal iSecond As Integer, ByVal iWorkCode As Integer)
        MsgBox("Raised event details here... [EnrollID, Year, Month, Day]...")
    End Sub
End Class

注意：我创建并使用 MyWrapperClass 将自定义设备名称嵌入到每个生物识别设备中，这样我就可以识别哪个设备 [如 CZKEM2] 引发了任何事件[喜欢CZKEM2.OnAttTransactionEx]

Public Class MyWrapperClass
    Public Property Name
    Private WithEvents CZKEM As zkemkeeper.CZKEM
    Public Event AttEventWrapper(SenderName As String, sEnrollNumber As String, iIsInValid As Integer, iAttState As Integer, iVerifyMethod As Integer, iYear As Integer, iMonth As Integer, iDay As Integer, iHour As Integer, iMinute As Integer, iSecond As Integer, iWorkcode As Integer)

    Public Sub New(WrapperName As String, CZKEMObject As zkemkeeper.CZKEM)
        Me.Name = WrapperName
        Me.CZKEM = CZKEMObject

    End Sub

    Private Sub HandleEvent(ByVal sEnrollNumber As String, ByVal iIsInValid As Integer, ByVal iAttState As Integer, ByVal iVerifyMethod As Integer, ByVal iYear As Integer, ByVal iMonth As Integer, ByVal iDay As Integer, ByVal iHour As Integer, ByVal iMinute As Integer, ByVal iSecond As Integer, ByVal iWorkCode As Integer) Handles CZKEM.OnAttTransactionEx
        RaiseEvent AttEventWrapper(Me.Name, sEnrollNumber, iIsInValid, iAttState, iVerifyMethod, iYear, iMonth, iDay, iHour, iMinute, iSecond, iWorkCode)
    End Sub
End Class

在我的主程序中，我使用了以下代码：

Sub ConnectToDevice()
        Dim iIP As String
        Dim iDevice As String
        Dim iPort As Integer
        For x = 1 To 2
            Select Case x
                Case 1
                    iIP = "122.3.47.43"
                    iDevice = "Device 1"
                Case 2
                    iIP = "192.168.10.201"
                    iDevice = "Device 2"
            End Select


            'This is the section where I create new instance of my ZKEMEventsClass
            Dim NewConnect As New ZKEMEventsClass
            NewConnect.AddBioHandler(iDevice, iIP, iPort)

        Next
End Sub

    Sub Disconnect()
        >>> For Each CZKEMObject As KeyValuePair(Of String, zkemkeeper.CZKEM) In MyWrapperClass.ListOfDevices
            >>> Dim NewRemoveHandler As New ZKEMEventsClass
            >>> NewRemoveHandler.RemoveBioHandler(CZKEMObject.Key, CZKEMObject.Value)
        >>> Next

    End Sub

问题 #1： 当我的每个事件处理程序都是从我的 ZKEMEventsClass 类的另一个实例创建的时，我如何才能删除它们？

问题 #2 如果问题 #1 无法回答，是否有其他[工作]选项可供我满足我的要求？

我现在在这里被困了一个星期，我在谷歌上找不到任何与我的问题类似的东西。

请任何人帮助我:(

Answer 1

当您想要删除事件时，这是您当前正在执行的操作：

Public Sub RemoveBioHandler(iDevice As String, CZKEM As zkemkeeper.CZKEM)
     MyNewWrapperClass = New MyWrapperClass(iDevice, CZKEM)
     RemoveHandler MyNewWrapperClass.AttEventWrapper, AddressOf LogRaised
End Sub

您正在创建一个 new ZkemEventClass 对象（它将处理程序绑定到它的事件，因为您已经在构造函数中定义了它）然后您在这个新创建的对象上调用 removeBioHandler，它成功删除处理程序。但是您从未使用过此对象，此对象不是您之前创建并正在使用的对象。它只存在于您定义它的子目录中。

在您的主程序中，您需要保留对您拥有的每个 ZKemEventClass 对象的引用，当需要摆脱它时，您将其称为 RemoveBioHandler 属性。这里的关键是你调用那个同一个对象的方法。不是新创建的。

至于保留对包装类的引用字典，您可以执行以下操作：

Public Class MyManagerClass
    Public MyDevicesDictionary As New Dictionary(Of String, MyWrapperClass)

    Public Sub AddDevice(Device As MyWrapperClass)
        MyDevicesDictionary.Add(Device.Name, Device)
        AddHandler Device.AttEventWrapper, AddressOf EventHandlerName
    End Sub


    Public Sub RemoveDevice(DeviceName As String)
        Dim Device As MyWrapperClass = MyDevicesDictionary(DeviceName)
        MyDevicesDictionary.Remove(DeviceName)
        RemoveHandler Device.AttEventWrapper, AddressOf EventHandlerName
    End Sub

    Public Sub EventHandlerName(Name, sEnrollNumber, iIsInValid, iAttState, iVerifyMethod, iYear, iMonth, iDay, iHour, iMinute, iSecond, iWorkCode)
        'do whatever you want to do here
    End Sub
End Class