How to put received serial text into multiple text boxes? - vb.net

Question

I am doing a serial communication project and would like to have the received string go into a text box based on which button was clicked to send the initial string and invoke a response.
The code for the ReceivedText is:
PrivateSub ReceivedText(ByVal [text] As String)
Button1.Clear()
Button2.Clear()
If Button1.InvokeRequired Then
RichTextBox1.text = [text].Trim("!")
End If
If Button2.InvokeRequired Then
RichTextBox2.Text = [text].Trim("!")
End If
EndSub
This just results in the received string going into both of the boxes instead of one or the other.
Is there any way to get the text to go in the appropriate box?

Answer 1

The key to remember is that .Net treats all serial comm as threads. Let me give you a simple example of updating textboxes from one of my programs that reads data from a scale.
Private Sub ComScale_DataReceived(sender As System.Object, e As System.IO.Ports.SerialDataReceivedEventArgs) Handles ComScale.DataReceived
If ComScale.IsOpen Then
Try
' read entire string until .Newline
readScaleBuffer = ComScale.ReadLine()
'data to UI thread because you can't update the GUI here
Me.BeginInvoke(New EventHandler(AddressOf DoScaleUpdate))
Catch ex As Exception : err(ex.ToString)
End Try
End If
End Sub
You'll note a routine DoScaleUpdate is invoked which does the GUI stuff:
Public Sub DoScaleUpdate(ByVal sender As Object, ByVal e As System.EventArgs)
Try
'getAveryWgt just parses what was read into something like this {"20.90", "LB", "GROSS"}
Dim rst() As String = getAveryWgt(readScaleBuffer)
txtWgt.Text = rst(0)
txtUom.Text = rst(1)
txttype.Text = rst(2)
Catch ex As Exception : err(ex.ToString)
End Try
End Sub
You CAN make it much more complicated if you choose (see post #15 of this thread for an example) but this should be enough to do what you need.