Android Question Problem with network

[stefanoxjx]

Hi guys, someone can tell me why this code don't send "Test line1" and "Test line2" but only "Test line3" and "Test line4"?

Sub Process_Globals
   
Dim Client As Socket

End Sub

Sub Globals
   
Client.Initialize("Client")
Dim Astreams As AsyncStreams

End Sub

Sub Activity_Create(FirstTime As Boolean)

  Activity.LoadLayout("1")

End Sub

Sub Activity_Resume
End Sub

Sub Activity_Pause (UserClosed As Boolean)
End Sub

Sub AStreams_Error
  ToastMessageShow("Errore", True)
End Sub

Sub Client_Connected (Successful As Boolean)
If Successful = False Then
  Msgbox(LastException.Message, "Error connecting")
  Return
  End If
  ToastMessageShow("Connect",False)
   
  Astreams.Initialize(Client.InputStream, Client.OutputStream, "AStreams")
End Sub

Sub SendCommand(text As String)
   Dim buffer() As Byte
  buffer = text.GetBytes("utf-8")
  Astreams.Write(buffer)
     
End Sub

Sub AStreams_NewData (Buffer() As Byte)
  Dim msg As String
  msg = BytesToString(Buffer, 0, Buffer.Length,"utf-8")
  ToastMessageShow(msg, False)
End Sub

Sub Button1_Click
Client.Connect("192.168.0.252",80,2000)
   Delay(3000)

   SendCommand("Test line1")
  SendCommand("Test line2")
   
   
End Sub
Sub Button2_Click
   
  SendCommand("Test line3")
  SendCommand("Test line4")

End Sub


Sub Delay(nMilliSecond As Long)
   Dim nBeginTime As Long
   Dim nEndTime As Long
   
   nEndTime = DateTime.Now + nMilliSecond
   nBeginTime = DateTime.Now
   Do While nBeginTime < nEndTime
   nBeginTime = DateTime.Now
   Log(nBeginTime)
   If nEndTime < nBeginTime Then Return
   DoEvents
   Loop
   
End Sub

I would like to connect, send packet (Test line1 & Test line 2) and disconnect with one touch, but seems that this solutions don't work
Please, help me.
Unfortunately, I'm newbe of B4A
Thanks.

Stefano

 

[KMatle]

After "Client.Connect" you have to wait until "Sub Client_Connected (Successful AsBoolean)" is called. AFTER Successful = true you can send commands.

Most of those calls (like connect) call a routine in Android's OS. This routine calls a defined sub when it is ready (here: Sub Client_Connected). You have to "wait" for it.

Connecting, waiting x secs and then sending commands without knowing if it is really connected cause errors. It's like you pass a crossing assuming that the lights are green without waiting for "green"

So move the connect statement to Activity_Create, disable the buttons (no send until connected) and debug it to see that the Sub Client_Connected is called. Inside Sub Client_Connected enable the send buttons again (now it is connected and you can send commands).

 

[stefanoxjx]

Hi KMatle and thanks for your explanation.
I would like to have a sub routine that connect, send data and disconnect.
About this, I would have two questions:
- I've tried to write a sub routine like this:

Sub Button1_Click
  Client.connect("192.168.0.252",80,2000)
  'I'm waiting for connection ready
  Do While (Client.connected=false)
  Loop
  SendCommand("bla bla")
  'Close connection
  Client.close
End Sub

Why Client.connected return true but SendCommand don't send any byte?
- Client.close de initialize the socket but I would like to close only connection without socket de initialization.
Exist a command to do it?

Thanks.

Stefano

 

[KMatle]

Take a look at Erels example: https://www.b4x.com/android/forum/threads/asyncstreams-tutorial.7669/#content

What you have to understand is that Android (like any other OS like Windows) is working with events.

As you can imagine there are a lot of programs running parallel on you phone. If one app/programm would block the whole cpu while in a loop (as you have it in your code) it would use 100% of the CPU and would stop all other running apps/programms on the phone. Android checks this and giving a prompt "App does not response" (wait/close it).

In the code you define Sub's and Android knows if event x is raised, it must call this sub.

In your app you execute "Client.Connect("192.168.0.252",80,2000)". Notice that after that your app has to "stop" at that point. No own waits - no loops -nothing like that - just do nothing! Just wait for the sub to be called.

Android gets "Client.Connect("192.168.0.252",80,2000)" and does all things needed to connect (your app is -let's say- "sleeping"). If Android is ready, it will call the event "Client_Connected" automatically and your app "awakes" again. You check if the connection is successful with "If Successful = true". When successful open a msgbox to tell the user that it's connected.

You have all the subroutines you need. Remove the connect from the button's click event to Activity_Create , remove all delays/waits and try.

After that we can talk about disconnect and further functions.