问题描述
我是 Kivy 的新手，我正在开发一个用于车辆维修的跟踪应用程序，我有一个约会列表，当您按下列表中的一个项目时，我正在尝试转到另一个屏幕，然后我不知道为什么它对我不起作用，因为它说它在不同的屏幕上，但不在应用程序上
from kivymd.app import MDApp
from kivy.lang.builder import Builder
from kivymd.uix.list import ThreeLineAvatarIconListItem
from kivymd.uix.list import ImageLeftWidget
from kivy.uix.screenmanager import Screen,ScreenManager,SwapTransition,CardTransition
from kivy.core.window import Window
import sqlite3
DatabaseConnection = sqlite3.connect('CarWorkshopDB.db')
cursor = DatabaseConnection.cursor()
Window.size= (400,650)
class MainScreen(Screen):
pass
class AddScreen(Screen):
pass
class DetailsScreen(Screen):
pass
class WorkApp(MDApp):
def build(self):
self.screen_manager = ScreenManager(transition=CardTransition())
self.screen_manager.add_widget(MainScreen(name='MainScreen'))
self.screen_manager.add_widget(AddScreen(name='AddScreen'))
self.screen_manager.add_widget(DetailsScreen(name='DetailsScreen'))
screen = Builder.load_file("test2.kv")
return screen
def on_start(self):
client = 'John smith'
cursor.execute("SELECT TrackingNumber,Plate,Status FROM Appointments WHERE Customer =?",(client,))
for i in cursor:
self.new_message(i[0],i[1],i[2])
def new_message(self,TrackingNumber,Vehicle,Process):
new_message = ThreeLineAvatarIconListItem(text=TrackingNumber,secondary_text=Vehicle,tertiary_text=Process)
new_message.add_widget(ImageLeftWidget(source='RepairIMG.jpg'))
new_message.bind(on_release=self.on_touch_down)
self.root.ids.list.add_widget(new_message)
def on_touch_down(self,x):
print(self.screen_manager.current)
self.screen_manager.current = "DetailsScreen"
self.screen_manager.transition.direction = 'right'
print(self.screen_manager.current)
WorkApp().run()
NavigationLayout:
ScreenManager:
id: screen_manager
MainScreen:
name : "MainScreen"
BoxLayout:
orientation:'vertical'
MDBottomNavigation:
panel_color: 1,.643,1
MDBottomNavigationItem:
name: 'screen 1'
text: 'Home'
icon: 'alpha-h-circle'
MDToolbar:
title: 'Add Repair'
md_bg_color: 1,1
elevation: 6
pos_hint: {'top':1}
Widget:
MDBottomNavigationItem:
name: 'screen 2'
text: 'Track'
icon: 'alpha-t-circle'
MDToolbar:
id: toolbar
title: 'Track History'
md_bg_color: 1,1
elevation: 6
pos_hint: {'top':1}
NavigationLayout:
x: toolbar.height
size_hint_y: 1.0 - toolbar.height/root.height
ScreenManager:
Screen:
name: 'ScrollViewScreen'
ScrollView:
MDList:
id: list
MDFloatingActionButton:
icon: 'plus'
md_bg_color: 1,1
on_release:
screen_manager.current = 'AddScreen'
screen_manager.transition = CardTransition()
screen_manager.transition.direction = "down"
pos_hint: {'x': .84,'y': .02}
MDBottomNavigationItem:
name: 'screen 4'
text: 'More'
icon: 'dots-horizontal'
MDToolbar:
title: 'More'
md_bg_color: 1,1
elevation: 6
pos_hint: {'top':1}
Widget:
MDLabel:
text: 'dfsfdsf'
halign: 'center'
AddScreen:
name: 'AddScreen'
id: Add
FloatLayout:
orientation: 'vertical'
MDToolbar:
id: toolbar2
title: 'Add Tracking Number'
md_bg_color: 1,1
elevation: 6
pos_hint: {'top':1}
MDIconButton:
icon : 'close'
pos_hint : {'top':0.98,'x':0.85}
on_release :
screen_manager.current = "Main"
screen_manager.transition = CardTransition()
screen_manager.transition.direction = "up"
FloatLayout:
x: toolbar2.height
size_hint_y: 1.0 - toolbar.height/root.height
ScatterLayout:
MDLabel:
text: 'Track Repair'
font_style: 'H4'
valign: 'top'
pos_hint: {'top':1}
text_size: self.size
size_hint: None,None
MDTextFieldRound:
icon_left: 'alpha-t-circle'
hint_text: 'Tracking Number'
normal_color: 1,1
pos_hint: {'y':.7}
text_size: self.size
MDTextFieldRound:
icon_left: 'alpha-p-circle'
hint_text: 'Postcode'
normal_color: 1,1
pos_hint: {'y':.6}
text_size: self.size
MDTextButton:
text: "Cant find your tracking number?"
custom_color: 1,1
pos_hint: {'y':.5}
halign: 'center'
MDRectangleFlatButton:
text: 'confirm'
pos_hint: {'y':.4}
valign: 'middle'
text_size: self.size
DetailsScreen:
name: 'DetailsScreen'
id: Details
BoxLayout:
orientation: 'vertical'
MDLabel:
text: 'details Screen?'
解决方法
问题在于，在您的 build() 方法中，您正在构建一个小部件树：
self.screen_manager = ScreenManager(transition=CardTransition())
self.screen_manager.add_widget(MainScreen(name='MainScreen'))
self.screen_manager.add_widget(AddScreen(name='AddScreen'))
self.screen_manager.add_widget(DetailsScreen(name='DetailsScreen'))
但是您的 GUI 中未使用此小部件树。 GUI 中的小部件树是从 kv 文件通过以下方式构建的：
screen = Builder.load_file("test2.kv")
当您的代码尝试使用以下方法更改当前 Screen 时：
self.screen_manager.current = "DetailsScreen"
它正在更改不在您的 GUI 中的 Screen 的当前 ScreenManager。
解决方法是为 self.screen_manager 分配正确的值，如下所示：
class WorkApp(MDApp):
def build(self):
screen = Builder.load_file("test2.kv")
self.screen_manager = screen.ids.screen_manager
return screen