python kivy “key_error: pos_hint”

Question

i am new in kivy.

i got this error over and over

File "_event.pyx", line 255, in kivy._event.EventDispatcher.bind (kivy_event.c:3629)
KeyError: 'pos_hint'

this is my code:

class RiegosBoxLayout(BoxLayout):

    def __init__(self, **kwargs):
        super(RiegosBoxLayout, self).__init__(**kwargs)
        self.orientation= "vertical"
        lb= Label(text= "Riegos programados", font_size= '30dp', bold= True, size_hint= (1, .10))       
        self.add_widget(lb)
        db= sqlite3.connect('../db/dbInvernadero.s3db')
        cursor = db.cursor()
        cursor.execute("select ID, descripcion from tbRiegos")
        la= ListAdapter(
                        data=["{}".format(i[1]) for i in cursor.fetchall()],
                        selection_mode='single', 
                        allow_empty_selection=False, 
                        cls= ListItemButton)

        #lv = ListView( item_strings=[str(i[1]) for i in cursor.fetchall()])
        self.add_widget(la) # if i pass lv, it goes ok
        db.close()


class MainScreen(Screen):

    def __init__(self, **kwargs):
        super(MainScreen, self).__init__(**kwargs)
        tb_panel= TabbedPanel(do_default_tab=False, size_hint=(1,1), pos_hint= {'center_x': .5, 'center_y': .5})
        tabs= ["Operaciones", "Riegos", "Valvulas", "Radiacion", "Configuracion"]

        for tb in tabs:

            if (tb == "Riegos"):
                tbi=TabbedPanelItem(text=tb)
                tbi.add_widget(RiegosBoxLayout())
                tb_panel.add_widget(tbi)
            else:
                tb_panel.add_widget(TabbedPanelItem(text=tb))

        self.add_widget(tb_panel)

class MainApp(App):

    def build(self):
        # Create the screen manager
        sm = ScreenManager()
        sc=MainScreen()
        sm.add_widget(sc)
        return sm

if __name__ == '__main__':
    MainApp().run()

Answer 1

ListAdapter is not a Widget . It works when you use ListView because that is a Widget . You need to provide the ListAdapter to the ListView :

lv = ListView(adapter=la)
self.add_widget(lv)