สอบถามเกี่ยวกับการใช้ System.Threading.Timer กับ Timer ธรรมดา

Imports System.Threading
Imports System.IO
Imports System.Data.SqlClient
Imports System.Net.Sockets


Public Class Form1
    Dim TchkAGV As System.Threading.Timer
    Dim call_back_to As TimerCallback
    Dim StreamWriter As StreamWriter
    Dim comm As String
    Dim strReceiveAGV As String = "HOME"
    Dim intA As Integer
    Dim strB As String

    Private Sub callt0(ByVal state As Object)
        Try
            TchkAGV.Dispose()
        Catch ex As Exception

        End Try
        Try

            If intA = 1 Then

                driveAGV(strB)

                StreamWriter = New StreamWriter("c:\writeThreading.txt", True) '';  //ใส่ PathFile ลงไปเลยครับ
                StreamWriter.WriteLine(driveAGV(strB)) ''; // จะเขียนอะไรละครับ ใส่ไรก็ได้ที่เป็น Stirng
                StreamWriter.Close() ''; //อย่าลืมสั่งปิดด้วยนะครับ
                intA = 0
            Else

                strReceiveAGV = driveAGV("0")

            End If


            'call_back_to = AddressOf callt0
            ' Me.t0 = New Threading.Timer(AddressOf callt0, Nothing, 2000, 1000)
            TchkAGV = New Threading.Timer(call_back_to, Nothing, 1000, 2000)


            '  Catch exsql As SqlCeException
            '   MsgBox(exsql.Message, MsgBoxStyle.Exclamation)
        Catch ex As Exception
            MsgBox(ex.Message, MsgBoxStyle.Exclamation)
            TchkAGV = New Threading.Timer(call_back_to, Nothing, 1000, 2000)

        End Try

    End Sub
    Function driveAGV(ByVal lineNO As String) As String
        '  Dim sBuf(4) As Byte
        '  Dim rLen, rInPut, sInput As UInteger
        '  TimerCheckbitReCeive.Interval = 5


        'Dim comm As String = lineNO
        comm = lineNO
        Dim returndata As String
        returndata = ""
        Dim tcpClient As New TcpClient
        Dim strIP As String
        Dim Client = New TcpClient() '50650

        Try
            Client = New TcpClient("192.168.0.188", 80)
            'Client = New TcpClient("192.168.10.3", 445)
            'tcpClient.Connect(IP, Port)

            strIP = "Ping is OK"
        Catch err As Exception
            strIP = "Ping not OK"
        End Try

        If strIP = "Ping not OK" Then


            returndata = "0000"
        Else
            returndata = strIP
        End If

        Return returndata

    End Function

    Private Sub timerNormal_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles timerNormal.Tick

        StreamWriter = New StreamWriter("c:\writeNoamal.txt", True) '';  //ใส่ PathFile ลงไปเลยครับ
        StreamWriter.WriteLine("Write Data Noamal") ''; // จะเขียนอะไรละครับ ใส่ไรก็ได้ที่เป็น Stirng
        StreamWriter.Close() ''; //อย่าลืมสั่งปิดด้วยนะครับ

    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        timerNormal.Enabled = True
        call_back_to = AddressOf callt0
        'Dim callt0 As System.Threading.TimerCallback(AddressOf task1)
        TchkAGV = New Threading.Timer(call_back_to, Nothing, 1000, 2000)
    End Sub

    Private Sub TimerchkAGV_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TimerchkAGV.Tick
        Select Case strReceiveAGV(2)

            Case "0"
                chkLabel()
        End Select
        txtStatusAGV1.Text = strReceiveAGV
        txtStatusAGV2.Text = comm
    End Sub
    Sub chkLabel()
      
        intA = 1
        strB = "iV01"
       

        strReceiveAGV = "HOME"
    End Sub
End Class