Terry Reedy wrote:
> On 3/18/2019 12:00 PM, Informatico de Neurodesarrollo wrote:
>> Hello friends:
>>
>> I am a beginner on programming in python.
>>
>> I want make a simple program that test continuously (every 5 seg) the
>> connection to internet and change the background color when are not
>> available. I try this , but not work properly:
>>
>> #!/usr/bin/env python3
>> # -*- coding: utf-8 -*-
>
> Not needed for py 3 where utf-8 is default
>
>> from tkinter import *
>> import socket, time
>>
>> def DetectarConexion():
>> testConn = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
>> try:
>> testConn.connect(('8.8.8.8', 80))
>> testConn.close()
>> return True
>> except:
>> testConn.close()
>> return False
>>
>> root = Tk()
>> root.title("Conexión")
>> root.geometry("80x50")
>>
>> while True:
>> if DetectarConexion():
>> # Background:Green
>> root.config(background="#38EB5C")
>> else:
>> # Background:Red
>> root.config(background="#F50743")
>> time.sleep(5)
>
> This is your problem. Loop with event loop in order to not block gui.
> See working code below.
>
>> root.mainloop()
>
> #!/usr/bin/env python3
>
> from tkinter import *
>
> connected = False
> def DetectarConexion():
> global connected
> connected = not connected
> return connected
>
> root = Tk()
> root.title("Conexión")
> root.geometry("80x50")
>
> def colorupdate():
> if DetectarConexion():
> # Background:Green
> root.config(background="#38EB5C")
> else:
> # Background:Red
> root.config(background="#F50743")
> root.after(1000, colorupdate) # 1000 milliseconds = 1 second
>
> colorupdate()
> root.mainloop()
If the DetectarConexion() function takes long to execute it will still block
the GUI because it is called indirectly by the callback.
In that case you may execute it in a separate thread:
#!/usr/bin/env python3
from tkinter import *
import random
import threading
import time
# global flag used to communicate between the checker thread
# and the GUI in the main thread. If the interaction gets more
# complex you may use a queue.Queue() instead.
connected = False
def DetectarConexion():
# simulate that the function takes
# 3 seconds to execute
time.sleep(3)
return random.random() < .7 # good with 70% probability
def update_connection_state():
global connected
while True:
connected = DetectarConexion()
time.sleep(1) # wait 1 second until the next check
def colorupdate():
if connected:
# Background:Green
root.config(background="#38EB5C")
else:
# Background:Red
root.config(background="#F50743")
root.after(1000, colorupdate) # 1000 milliseconds = 1 second
checker_thread = threading.Thread(
target=update_connection_state, daemon=True
)
checker_thread.start()
root = Tk()
root.title("Conexión")
root.geometry("80x50")
colorupdate()
root.mainloop()
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