SmartPDCode/f407/applications/packages/LVGL-v8.3.11/examples/event/lv_example_event_1.py

class Event_1():
    def __init__(self):
        self.cnt = 1
        #
        # Add click event to a button
        #

        btn = lv.btn(lv.scr_act())
        btn.set_size(100, 50)
        btn.center()
        btn.add_event_cb(self.event_cb, lv.EVENT.CLICKED, None)

        label = lv.label(btn)
        label.set_text("Click me!")
        label.center()

    def event_cb(self,e):
        print("Clicked")

        btn = e.get_target()
        label = btn.get_child(0)
        label.set_text(str(self.cnt))
        self.cnt += 1

evt1 = Event_1()