Send a form to a sub declared in a DLL files - vb.net

Question

I'm trying to create (finally) my own DLL files to some code that I will use constantly in a new project, I'm using Visual Basic 2010
I created the DLL correctly but I got a problem with a sub have the code Me.Handle
I don't know how to send the "me" to my sub
This is my sub (from an example in msdn)
Sub Start_Detection()
Dim di As New DEV_BROADCAST_DEVICEINTERFACE
di.dbcc_size = CUInt(Marshal.SizeOf(GetType(DEV_BROADCAST_DEVICEINTERFACE)))
di.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE
di.dbcc_reserved = 0
di.dbcc_classguid = Guid.Parse("{88BAE032-5A81-49f0-BC3D-A4FF138216D6}")
di.dbcc_name = Nothing
hDevNotify = RegisterDeviceNotification(Me.Handle, di, DEVICE_NOTIFY_WINDOW_HANDLE)
End Sub
When I put that inside a DLL, I don't know how to send the Me because in the DLL project says that "Me" isn't a member of my DLL project.
If I declare the sub as Sub Start_Detection(ByRef Form) or Sub Start_Detection(ByVal Form) the DLL project works ok, but when I call it from the windows form project a "Null Reference Exception" happen.
Is not possible to send forms as arguments in Visual Basic 2010 ?
Thanks!
Edit: I'm calling the sub in this way
Private Sub Frm_Config_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
MyDLL.Start_Detection(Me)
End Sub

Answer 1

You might also want to consider using the following naming convention for the parameter
Sub Start_Detection (ByVal sender As System.Object)
or
Sub Start_Detection (ByVal handle As IntPtr)
When your calling the method, pass the handle value to the Class method
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
If Me.IsHandleCreated Then
RecieveHandle.Start_Detection(Me.Handle)
End If
End Sub
Then once your in the class module, you can do a common trick to confirm the variable has been supplied and don't pass a reference to the whole form via the "Me" (VB) or "This" (C#) variable.
Public Class RecieveHandle
Public Shared Sub Start_Detection(ByVal sender As System.Object)
If sender Is Nothing Then
Throw New ArgumentException("Method requires sender parameter to be supplied")
End If
If Not TypeOf (sender) Is IntPtr Then
Throw New ArgumentException("Method requires a valid pointer (handle) to the form.")
End If
Dim myFormHandle As IntPtr = CType(sender, IntPtr)
Debug.Print(myFormHandle.ToInt64.ToString)
End Sub
End Class

Answer 2

Me belongs to a form not a dll. If you pass the IntPtr you will be fine.
Sub Start_Detection(ptr As IntPtr)
Dim di As New DEV_BROADCAST_DEVICEINTERFACE
di.dbcc_size = CUInt(Marshal.SizeOf(GetType(DEV_BROADCAST_DEVICEINTERFACE)))
di.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE
di.dbcc_reserved = 0
di.dbcc_classguid = Guid.Parse("{88BAE032-5A81-49f0-BC3D-A4FF138216D6}")
di.dbcc_name = Nothing
hDevNotify = RegisterDeviceNotification(ptr, di, DEVICE_NOTIFY_WINDOW_HANDLE)
End Sub
Usage:
Start_Detection(Me.Handle)