TCP Socket (re-connecting) issue

[qsrtech]

Hi I'm using TCP "Socket" to connect to a POS printer. Everything connects fine and communicates fine. The problem arises after I call ASocket.Close. When I try to reuse my Socket by calling ASocket.Connect again later, the Successful is always false in the connected event.

I'm not sure if this is related, but I do have similar issues when using B4A Bridge. Essentially if my connection get's lost, when I try to re-connect, it fails. I either have to re-start bridge on my device, which doesn't always help, or re-start b4a. Any ideas or suggestions regarding the socket issue?

 

[Erel]

What is the value of Log(LastException)?

 

[qsrtech]

Last Exception

Hi Erel, this is what i get when adding log(lastexception) to the Socket_Connected event:

First Time connecting:
(Exception) Not initialized

Everytime after first "Close"
(NullPointerException) java.lang.NullPointerException

Note: I also checked lastexception before and after Socket.Close and both are Not Initalized

 

[Erel]

You should check LastException inside the Connected event (when Success is false).

 

[qsrtech]

lastexception

that is the lastexception in the connect event when false

 

[Erel]

Seems like you are not initializing the socket. Can you post your code?

 

[qsrtech]

code

Working now. Thanks! See comment in cmdConnect_Click

Sub Activity_Create(FirstTime As Boolean)
   'Do not forget to load the layout file created with the visual designer. For example:
   Activity.LoadLayout("tcpPrinterTest")
   If ASocket.IsInitialized=False Then
      ASocket.Initialize("ASocket")
   End If
   If aUDP.IsInitialized=False Then
      aUDP.Initialize("UDP",0,1024)
   End If
End Sub

Sub cmdConnect_Click
   'just added this If then and everything works correctly now
    'must have missed the details that initializing was required again after a close
    If ASocket.IsInitialized=False Then
      ASocket.Initialize("ASocket")
   End If
   ASocket.Connect(txtServer.Text,txtPort.Text,5000)
End Sub

Sub ASocket_Connected (Successful As Boolean)
   If Successful Then
      cmdConnect.Enabled=False
      cmdDisconnect.Enabled=True
      cmdCut.Enabled=True
      cmdESC.Enabled=True
      AOutputStream=ASocket.OutputStream
   End If
   Log(LastException)
End Sub

Sub cmdDisconnect_Click
   cmdConnect.Enabled=True
   cmdDisconnect.Enabled=False
   cmdCut.Enabled=False
   cmdESC.Enabled=False
   Log(LastException) 
   ASocket.Close
   Log(LastException) 
   AOutputStream=Null
End Sub