我将如何在 for 循环中访问按钮状态。我想检查哪个按钮被按下,然后根据这个选择我想要显示的屏幕。我知道我可以通过 ids.state 访问状态,但是我不知道如何在循环中执行此操作。下面的代码是我目前访问的方式。
if self.root.ids.main_screen.ids.second_screen_button.state == "down":
self.sm.current = "second_screen"
是否可以检查每个按钮的状态,然后返回按下哪个按钮的 id?或者访问按下按钮的ID?然后我可以将其与屏幕 ID 进行比较。
此外,当按钮不在屏幕根目录时如何更改转换。下面的代码不起作用。它给出了以下错误 AttributeError:'BackgroundLayout' 对象没有属性'manager'。这是有道理的,因为根是RelativeLayout。
<BackgroundLayout>:
Button:
size_hint: None, None
text: "Home button"
size: root.width/4, root.height/4
on_release:
root.manager.transition = SlideTransition(direction="right", duration=0.25)
app.home_screen()
在这种情况下,是否应该在 python 中更改转换?我一直无法找到如何在 python 中动态地执行此操作。
请参阅下面的代码以供参考。请注意,我从下面的代码中删除了转换,以便它可以运行
<main.py>
from kivy.app import App
from kivy.uix.screenmanager import ScreenManager, Screen, SlideTransition
from kivy.uix.relativelayout import RelativeLayout
class MainScreen(Screen):
def change_screen(self):
self.manager.current = "steak_screen"
class SecondScreen(Screen):
pass
class ThirdScreen(Screen):
pass
class Manager(ScreenManager):
pass
class BackgroundLayout(RelativeLayout):
pass
class MainApp(App):
def build(self):
self.sm = Manager()
return self.sm
# Change screen based on button pressed
def change_screen(self):
if self.root.ids.main_screen.ids.second_screen_button.state == "down":
self.sm.current = "second_screen"
if self.root.ids.main_screen.ids.third_screen_button.state == "down":
self.sm.current = "third_screen"
# Return to main screen when pressed
def home_screen(self):
self.sm.current = "main_screen"
MainApp().run()
<main.kv>
#:import SlideTransition kivy.uix.screenmanager.SlideTransition
#Background layout for every screen
<BackgroundLayout>:
Button:
size_hint: None, None
text: "Home button"
size: root.width/4, root.height/4
on_release:
app.home_screen()
# Main Screen
<MainScreen>
BackgroundLayout:
Label:
text: "Home"
Button:
id: second_screen_button
size_hint: None, None
size: root.width/4, root.height/4
pos: root.x + root.width/4, 0
text: "second screen button"
on_press:
self.state = "down"
app.change_screen()
self.state = "normal"
Button:
id: third_screen_button
size_hint: None, None
size: root.width/4, root.height/4
pos: root.x + root.width/2, 0
text: "third screen button"
on_press:
self.state = "down"
app.change_screen()
self.state = "normal"
<SecondScreen>
BackgroundLayout:
<ThirdScreen>
BackgroundLayout:
# Screen manager
<Manager>:
id: _manager
MainScreen:
id: main_screen
manager: _manager
name: "main_screen"
SecondScreen:
id: second_screen
manager: _manager
name: "second_screen"
ThirdScreen:
id: third_screen
manager: _manager
name: "third_screen"