Visual Basic

Private Sub DataReceived( _
                     ByVal sender As Object, _
                     ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) _
                     Handles serialPort.DataReceived

       Dim stringCom As String = serialPort.ReadTo("G")
       serialPort.ReadExisting()



       BackgroundWorker.RunWorkerAsync(stringCom)


   End Sub

   Private Sub backgroundworker_Dowork(ByVal sender As Object, ByVal e As DoWorkEventArgs) Handles BackgroundWorker.DoWork
       Dim argument As Object = e.Argument


       For Value As Integer = 0 To 1
           If BackgroundWorker.CancellationPending Then

               Exit For

           End If

           BackgroundWorker.ReportProgress(Value, argument)
           BackgroundWorker.CancelAsync()
       Next

       ' Threading.Thread.Sleep(100)

   End Sub
   Private Sub backgroundworker_Progresschanged(ByVal sender As Object, ByVal e As ProgressChangedEventArgs) Handles BackgroundWorker.ProgressChanged
       Me.txtbxWeight.Text = e.UserState   This is where it says "Cross-thread operation not valid: Control 'txtbxWeight' accessed from a thread other than the thread it was created on."


   End Sub

Private Sub DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles serialPort.DataReceived
   Dim stringCom As String = serialPort.ReadExisting.ToString()
   TextChange(StringCom)
End Sub

Delegate Sub TextChangeDelegate(ByVal Str As String)

Sub TextChange(ByVal Str As String)
   If Me.txtbxWeight.InvokeRequired Then
      Dim d As New TextChangeDelegate(AddressOf TextChange)
      Me.Invoke(d, Str)
   Else
      Me.txtbxWeight.Text = Str
   End If
End Sub

Munna Sarfraz Ahmad wrote:

But objects are still passed by reference.

public sub sub1(byref x as collection)
  x.add(45)
  x=new collection
  x.add(23)
end sub

public sub sub2(byval x as collection)
  x.add(45)
  x=new collection
  x.add(23)
end sub

Munna Sarfraz Ahmad wrote:

The keyword SET is gone - Since everything in VB.NET is an object.

Munna Sarfraz Ahmad wrote:

We can also create a class destructor, which is equivalent to Class_Terminate event in VB 6.0, by adding a sub-procedure called Finalize to our class.