我正在尝试创建一个具有两个屏幕的应用程序，一个是登录屏幕，下一个是主页。我无法在第二个屏幕上合并Kivy代码。如何添加代码，以便可以切换到第二个屏幕？
from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.image import Image
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.lang import Builder
from kivy.uix.label import Label
class SigninWindow(BoxLayout):
def __init__(self, **kwargs):
super().__init__(**kwargs)
def validate_user(self):
user = self.ids.username_field
pwd = self.ids.pwd_field
info = self.ids.info
uname = user.text
passw = pwd.text
if uname == '' or passw == '':
info.text = '[color=#FF0000]username and/ or password required[/color]'
else:
if uname == 'admin' and passw == 'admin':
info.text = '[color=#00FF00]Logged In successfully![/color]'
else:
info.text = '[color=#FF0000]Invalid Username and/or Password[/color]'
class SigninApp(App):
def build(self):
return SigninWindow()
if __name__=="__main__":
sa = SigninApp()
sa.run()
kvfile：
<FlatButton@ButtonBehavior+Label>:
font_size: 16
<SigninWindow>:
id: main_win
orientation: "vertical"
spacing: 10
space_x: self.size[0]/3
canvas.before:
Color:
rgba: (1,1,1, 1)
Rectangle:
size: self.size
pos: self.pos
BorderImage:
source: 'E:\pythonpics/blu2.png'
pos: self.pos
size: self.size
BoxLayout:
size_hint_y: None
height: 50
canvas.before:
Color:
rgba: (.06, .45, .45, 1)
Rectangle:
size: self.size
pos: self.pos
Label:
text: "Hello! Dear User Please Sign In"
bold: True
size_hint_x: .9
BoxLayout:
orientation: 'vertical'
padding: main_win.space_x, 10
#spacing: 20
BoxLayout:
orientation: "vertical"
spacing: 10
size_hint_y: None
height: 100
Label:
id: info
text: ''
markup: True
size_hint_y: None
height: 20
TextInput:
id: username_field
hint_text: "Username"
multiline: False
focus: True
on_text_validate: pwd_field.focus = True
TextInput:
id: pwd_field
hint_text: "Password"
multiline: False
password: True
on_text_validate: root.validate_user()
Label:
id: sp
size_hint_y: None
height: 40
Button:
text: "Sign In"
size_hint_y: None
height: 40
background_color: (.06,.45,.45, 1)
background_normal: ''
on_release: root.validate_user()
Label:
id: sp2
答案 0 :(得分：0)
欢迎来到Stackoverflow！
您需要一个ScreenManager和Screen。您可以通过ScreenManager.current = "Name of Other Screen"切换到特定屏幕。
您可能想更改窗口小部件，因此可以省略诸如App.get_running_app().root.current之类的东西。
Your app python code:
from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.image import Image
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.lang import Builder
from kivy.uix.label import Label
Builder.load_string("""
<Rootwidget>:
Screen:
name: "SignIn"
SigninWindow:
Screen:
name: "SignedIn"
Label:
text: "You have signed in."
<FlatButton@ButtonBehavior+Label>:
font_size: 16
<SigninWindow>:
id: main_win
orientation: "vertical"
spacing: 10
space_x: self.size[0]/3
canvas.before:
Color:
rgba: (1,1,1, 1)
Rectangle:
size: self.size
pos: self.pos
BorderImage:
source: 'E:\pythonpics/blu2.png'
pos: self.pos
size: self.size
BoxLayout:
size_hint_y: None
height: 50
canvas.before:
Color:
rgba: (.06, .45, .45, 1)
Rectangle:
size: self.size
pos: self.pos
Label:
text: "Hello! Dear User Please Sign In"
bold: True
size_hint_x: .9
BoxLayout:
orientation: 'vertical'
padding: main_win.space_x, 10
#spacing: 20
BoxLayout:
orientation: "vertical"
spacing: 10
size_hint_y: None
height: 100
Label:
id: info
text: ''
markup: True
size_hint_y: None
height: 20
TextInput:
id: username_field
hint_text: "Username"
multiline: False
focus: True
on_text_validate: pwd_field.focus = True
TextInput:
id: pwd_field
hint_text: "Password"
multiline: False
password: True
on_text_validate: root.validate_user()
Label:
id: sp
size_hint_y: None
height: 40
Button:
text: "Sign In"
size_hint_y: None
height: 40
background_color: (.06,.45,.45, 1)
background_normal: ''
on_release: root.validate_user()
Label:
id: sp2
""")
class Rootwidget(ScreenManager):
pass
class SigninWindow(BoxLayout):
def __init__(self, **kwargs):
super().__init__(**kwargs)
def validate_user(self):
user = self.ids.username_field
pwd = self.ids.pwd_field
info = self.ids.info
uname = user.text
passw = pwd.text
if uname == '' or passw == '':
info.text = '[color=#FF0000]username and/ or password required[/color]'
else:
if uname == 'admin' and passw == 'admin':
info.text = '[color=#00FF00]Logged In successfully![/color]'
App.get_running_app().root.current = "SignedIn"
else:
info.text = '[color=#FF0000]Invalid Username and/or Password[/color]'
class SigninApp(App):
def build(self):
return Rootwidget()
if __name__=="__main__":
sa = SigninApp()
sa.run()