FalconX4 Scanner issue with vbnet and datalogic API

i write an application using vbnet and Datalogic.API
All working fine , i open the application and i can capture the scanned barcode.
When i close the application i dispose the scanner using
If dcdEvent.IsListening() Then
End If

When i run the application the secon time the scanner doesn’t send the scanned code to the application.

Any idea to fix this issue ?

Hello @MASSIMO_Chimetto

If the instance of DcdEvent is listening to a Decoder, you need to make sure to tell DcdEvent to stop listening before we delete DecodeHandler
I copy here below a code sample for a good de-initialization of DecodeHandler and DecodeEvent.


   /// Before the app or the dialog is closed, this method is called.
   /// We do any necessary dialog clean up before the app shuts down.
   private void DecoderDisposal()
       // If our instance of DcdEvent is listening to the decoder, we need to make
       // sure we tell DcdEvent to stop listening.
       if (dcdEvent != null)
           if (dcdEvent.IsListening)
           dcdEvent.Scanned -= dcdEvent_Scanned();  //optional
           dcdEvent.TimeOut -= dcdEvent_TimeOut();   //optional

           dcdEvent.Dispose();  //optional
           dcdEvent = null; //optional                
      if (hDcd != null)


Private Sub DecoderDisposal()
     If dcdEvent IsNot Nothing Then
         If dcdEvent.IsListening Then
         End If
         dcdEvent.Scanned -= dcdEvent_Scanned()
         dcdEvent.TimeOut -= dcdEvent_TimeOut()
         dcdEvent = Nothing
     End If
     If hDcd IsNot Nothing Then
     End If
 End Sub

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Simone Callegari
Datalogic Mobile - Products Specialist SW Engineer