Kivy Switch on_active

Question

I want to use a Kivy Switch to turn something on/off. I am trying to stick with: http://kivy.org/docs/api-kivy.uix.switch.html , but there is no .kv example.

I have the following code, abstracted to the problem.

main.py:

def PID_an_aus(self, instance, value):
        if value is True:
            do something
        else:
            do something else

kv File:

Switch:
    on_active: root.PID_an_aus()

The GUI is working properly as long as I don't click on the switch. As soon as I click on the switch, the Programm closes without an error.

I feel a bit stupid right know, can someone enlighten me? Thanks in advance!

Answer 1

The function is deblared as...

def PID_an_aus(self, instance, value):

...but you call it with...

on_active: root.PID_an_aus()

The problem is that you didn't call it with any arguments, whereas you declared it to expect two.

You could instead do

    on_active: root.PID_an_aus(self, self.active)

As soon as I click on the switch, the Programm closes without an error.

Is there really no traceback here? You should get a 'function received wrong number of arguments (expected 3 got 1)' or similar.