将数据从全局线程传递到Win窗体VB.Net

Question

我编写了一个包含两种形式的程序

1. FrmMain - 这是主要形式
2. FrmTreeView - 这是子表格

在FrmTreeView中，我有一个创建getData对象的方法，并放入名为_MyPoolingThreads的全局变量，该变量的类型为List(of getData)。 _MyPoolingThreads是一个可以从任何形式访问的全局变量。

在getData类中，我使用了每秒滴答的线程计时器，并使用MODBUS RTU协议从我的设备中获取数据。成功从设备中获取数据后，我需要在主表单FrmMain上显示此数据。您能否建议我如何实现这一机制？

以下是FrmTreeView的代码：

Imports System.Threading
Imports WeifenLuo.WinFormsUI.Docking

Public Class frmTreeView
             Inherits DockContent

Private Sub cmsConnectionStartPooling_Click(sender As Object, e As EventArgs) Handles cmsConnectionStartPooling.Click
    Dim _node = _CheckConnectionNode(tvNodes.SelectedNode)

    If Not IsNothing(_node) Then
        Dim _threadObject = _GetDataObject(_node) 

        If IsNothing(_threadObject) Then
            _threadObject = New getData(_node, tvNodes) 'Here getData Object is created and added to _MyPooligThreads
            _MyPoolingThreads.Add(_threadObject)
            _threadObject.StartPooling(True)
        Else
            _threadObject.StartPooling(True)
        End If
    End If
End Sub

End Class

以下是getData类的代码：

Public Class getData

'Thread Timer
Private _ThreadTimer As Timer
Public Property _TimerStarted As Boolean

Public Sub New(ByRef connNode As ConnectionNode, ByRef tv As TreeView)
    _Name = connNode.DataItem.id.ToString
    _connectionNode = connNode
    _tv = tv

    Handle_ComPortEventDelegate = New Handle_ComPortEventSUB(AddressOf Handle_ComPortEvent)
    Handle_PollEventDelegate = New Handle_PollEventSUB(AddressOf Handle_PollEvent)
End Sub


Private Function _InitMBControl() As Boolean
    'Do init Stuff
End Function

Public Sub StartPooling(val As Nullable(Of Boolean))
    If Not IsNothing(val) Then
        If val Then
            If IsNothing(_ThreadTimer) Then
                If _InitMBControl() Then
                    _ThreadTimer = New Timer(New TimerCallback(AddressOf _GetData), Nothing, 0, Timeout.Infinite)
                    _TimerStarted = True
                Else
                    _TimerStarted = False
                End If
            Else
                _ThreadTimer.Change(_GetPollDelay, Timeout.Infinite)
                _TimerStarted = True
            End If
        End If

    Else
        If _TimerStarted Then
            _ThreadTimer.Change(_GetPollDelay, Timeout.Infinite)
        Else
            _tv.Invoke(Handle_ComPortEventDelegate, New Object() {New MyEventArgs With {.EvenyType = MyEnums.MyPrivateEvents.POOLING_STOPPED}})
        End If
    End If
End Sub


Private Sub _GetData(ByVal state As Object)
    _ThreadTimer.Change(Timeout.Infinite, Timeout.Infinite)

    Dim _dataTS As Date = Date.Now

    Select Case _connectionNode.DataItem.conn_type
        Case MyEnums.ConnectionType.MODBUS_RTU

            If _connectionNode.Nodes.Count > 0 Then
                Dim _nd As DeviceNode = CType(_connectionNode.Nodes(0), DeviceNode)
                While _TimerStarted And Not IsNothing(_nd)
                    If Not _nd.DataItem.skip And _nd.TimeOutCount <= 3 Then
                        _GetModbusRTUData(_nd, _dataTS)
                    Else
                        _nd.SkipCount = _nd.SkipCount + 1
                        If _nd.SkipCount > _nd.TimeOutCount * 2 Then
                            _nd.SkipCount = 0
                            _nd.TimeOutCount = 0
                        End If
                    End If

                    If Not IsNothing(_nd.NextNode) Then
                        _nd = CType(_nd.NextNode, DeviceNode)
                    Else
                        _nd = Nothing
                    End If
                End While
            End If

        Case MyEnums.ConnectionType.MODBUS_RTU_OVER_TCP

        Case MyEnums.ConnectionType.MODBUS_TCP
    End Select

    StartPooling(Nothing)
End Sub

Private Sub _GetModbusRTUData(ByRef _var As DeviceNode, ByVal _ts As DateTime)
    Dim _modbusData = New Short(_var.DataItem._GetQty) {}

    _modbusRTUResult = _modbusRTU.ReadHoldingRegisters(CByte(_var.DataItem.modbus_id),
                                                       CUShort(_var.DataItem.modbus_start_address),
                                                       CUShort(_modbusData.Length - 1), _modbusData)

    Select Case _modbusRTUResult
        Case MBS.Result.SUCCESS
            _tv.Invoke(Handle_PollEventDelegate, New Object() {New MyEventArgs With {.MyNode = _var,
                                                                                     .valueDate = _ts,
                                                                                     .EvenyType = MyEnums.MyPrivateEvents.DATA_RECEIVED}})
            For Each chnl As ChannelNode In _var.Nodes
                chnl.DataItem.DataVal = _GetChannelData(chnl, _modbusData)
                _tv.Invoke(Handle_PollEventDelegate, New Object() {New MyEventArgs With {.MyNode = chnl,
                                                                                         .valueDate = _ts,
                                                                                         .EvenyType = MyEnums.MyPrivateEvents.CHANNEL_DATA_RECEIVED}})

                **'I want to pass data received here to FrmMain**                                                                        
            Next
        Case MBS.Result.RESPONSE_TIMEOUT


        Case MBS.Result.WRITE

        Case MBS.Result.ISCLOSED

    End Select
End Sub

Private Function _GetChannelData(ByRef chnl As ChannelNode, ByRef _dt As Short()) As Decimal
 'Do stuff here
End Function

Private Delegate Sub Handle_ComPortEventSUB(e As MyEventArgs)
Private Handle_ComPortEventDelegate As Handle_ComPortEventSUB
Private Sub Handle_ComPortEvent(e As MyEventArgs)

End Sub

Private Sub ClearPortAndTimerThread()

End Sub



Private Delegate Sub Handle_PollEventSUB(e As MyEventArgs)
Private Handle_PollEventDelegate As Handle_PollEventSUB
Private Sub Handle_PollEvent(e As MyEventArgs)

End Sub
End Class