vb.NET Serial Comport USB Multi Scanner and Connector.

Imports System.Runtime.InteropServices
Imports System.Text

Public Class Form1

    <DllImport("kernel32")> Private Shared Function WritePrivateProfileString(section As String, key As String, val As String, filePath As String) As Long
    End Function
    <DllImport("kernel32")> Private Shared Function GetPrivateProfileString(section As String, key As String, def As String, retVal As StringBuilder, size As Integer, filePath As String) As Integer
    End Function

    Private Const WM_DEVICECHANGE As Integer = &H219
    Private Const DBT_DEVICEARRIVAL As Integer = &H8000
    Private Const DBT_DEVICEREMOVECOMPLETE As Integer = &H8004

    Protected Overrides Sub WndProc(ByRef m As System.Windows.Forms.Message)
        If m.Msg = WM_DEVICECHANGE Then
            If m.WParam.ToInt32 = DBT_DEVICEARRIVAL Then
                GetPorts()
            ElseIf m.WParam.ToInt32 = DBT_DEVICEREMOVECOMPLETE Then
                GetPorts()
            End If
        End If
        MyBase.WndProc(m)
    End Sub

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        GetPorts()
    End Sub

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim devices As String = ""
        devices = iniread("Settings", "AutoConnectUSB") + "," + ListBox1.SelectedItem
        If devices.ToString.EndsWith(",") Then
            devices = devices.ToString.Substring(0, devices.Length - 1)
        End If
        iniwrite("Settings", "AutoConnectUSB", devices)
    End Sub

    Dim isConnected As Boolean

    Private Sub GetPorts()
        Dim key As Microsoft.Win32.RegistryKey = Microsoft.Win32.Registry.LocalMachine.OpenSubKey("HARDWARE\DEVICEMAP\SERIALCOMM")
        ListBox1.Items.Clear()
        For Each item In key.GetValueNames
            ListBox1.Items.Add(item.Replace("\Device\", ""))
        Next

        For Each item In key.GetValueNames
            For Each device In iniread("Settings", "AutoConnectUSB").ToString.Split(",")
                If item.Replace("\Device\", "") = device Then
                    SerialPort1.PortName = key.GetValue(item)
                    If isConnected = False Then
                        Try
                            SerialPort1.Open()
                            isConnected = True
                            Me.Text = "Connected"
                            Exit For
                        Catch ex As Exception
                            GetPorts()
                            Exit Sub
                        End Try
                    Else
                        Try
                            SerialPort1.Close()
                            isConnected = False
                            Me.Text = "Disconnected"
                            GetPorts()
                            Exit For
                        Catch ex As Exception
                            MsgBox("Already Disconnected")
                            Exit Sub
                        End Try
                    End If
                End If
            Next
        Next
    End Sub

    Public path As String = My.Application.Info.DirectoryPath + "\LionTrack IButton Config.ini"
    Public Sub iniwrite(Section As String, Key As String, Value As String)
        WritePrivateProfileString(Section, Key, Value, path)
    End Sub
    Public Function iniread(Section As String, Key As String) As String
        Dim temp As New StringBuilder(255)
        Dim i As Integer = GetPrivateProfileString(Section, Key, "", temp, 255, path)
        Return temp.ToString()
    End Function

End Class