It took me several hours to find the mistake, but I couldn't find it.
I wrote a program for UDP communication in python. The server and client of Python had no problem sending and receiving messages, but when they were sent in b4a, they never received messages.
I'm not familiar with Python, maybe it's a python problem, maybe, I'm not sure.
Any help is welcome, THX
The python codes:
	
	
	
	
	
	
	
		
			
			
			
			
			
		
	
	
	
		
	
	
		
	
The B4a Part:
	
	
	
	
	
	
	
		
			
			
			
			
			
		
	
	
	
		
	
	
		
	
			
			I wrote a program for UDP communication in python. The server and client of Python had no problem sending and receiving messages, but when they were sent in b4a, they never received messages.
I'm not familiar with Python, maybe it's a python problem, maybe, I'm not sure.
Any help is welcome, THX
The python codes:
			
				B4X:
			
		
		
		# -*- coding: utf-8 -*-
import socket
import re 
import webbrowser
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.bind(('', 9999))
print 'Bind UDP on 9999...'
while True:
    data, addr = s.recvfrom(2048)
    print 'Received from %s:%s.' % addr
    print 'get: %s' %data
    s.sendto('Hello, %s!' % data, addr)The B4a Part:
			
				B4X:
			
		
		
		#Region  Project Attributes 
    #ApplicationLabel: B4A Example
    #VersionCode: 1
    #VersionName: 
    'SupportedOrientations possible values: unspecified, landscape or portrait.
    #SupportedOrientations: unspecified
    #CanInstallToExternalStorage: False
#End Region
#Region  Activity Attributes 
    #FullScreen: False
    #IncludeTitle: True
#End Region
Sub Process_Globals
    'These global variables will be declared once when the application starts.
    'These variables can be accessed from all modules.
    Dim udp_socket As UDPSocket
    Dim udport As Int = 9999
End Sub
Sub Globals
    'These global variables will be redeclared each time the activity is created.
    'These variables can only be accessed from this module.
    Private btnSend As Button
    Private urlText As EditText
End Sub
Sub Activity_Create(FirstTime As Boolean)
    'Do not forget to load the layout file created with the visual designer. For example:
    'Activity.LoadLayout("Layout1")
    'in layer 1 just a edittext name urlText and a button name btnSend
    Activity.LoadLayout("1")
   
End Sub
Sub Activity_Resume
    udp_socket.Initialize("UDP",udport, 8000)
End Sub
Sub Activity_Pause (UserClosed As Boolean)
    udp_socket.Close
End Sub
''
Sub udp_send(s As String,desip As String,udpsocket As UDPSocket)
    Dim Packet As UDPPacket
    Dim data() As Byte
   
   
    data = s.GetBytes("UTF-8")
    Packet.Initialize(data, desip, 5000)
   
    udpsocket.Send(Packet)
   
    ToastMessageShow(" byte send " & s.ToUpperCase,False)
   
End Sub
Sub urlText_TextChanged (Old As String, New As String)
   
End Sub
'' can receive messages
Sub UDP_PacketArrived (Packet As UDPPacket)
    If Packet.Length <= 0 Then Return
   
    Dim msg As String
    msg = BytesToString(Packet.Data, Packet.Offset, Packet.Length, "UTF-8")
   
    ToastMessageShow(msg,False)
   
End Sub
Sub btnSend_Click
    udp_send(urlText.Text,"192.168.1.255",udp_socket)
   
End Sub 
				 
 
		 
 
		 
 
		