使用Kivy Factory,我已在MainWindow
类中实例化了ApplyPage
类,我试图从我的MainWindow类访问self.placementtext
变量,当我尝试将其初始化为None时,从ApplyPage
访问它,返回为None
。我知道它返回为None
,因为那是我初始化时的样子,但是我想知道任何可能的方法来访问在def printtext(self)
函数中分配给它的原始值。有关如何执行此操作的任何想法,请参见此处,这是我的代码。
class MainWindow(Screen):
search_string1 = ObjectProperty(None)
search_string2 = ObjectProperty(None)
def __init__(self, **kwargs):
super(MainWindow, self).__init__(**kwargs)
self.placementtext = None
self.searchbutton = Button( pos_hint = {"center_x": 0.5, "center_y": 0.5}, size_hint= (0.2, 0.1), font_name = 'fonts/Qanelas-Heavy.otf', text= "Search", background_color = (0.082, 0.549, 0.984, 1.0), background_normal= '', font_size = 20)
self.searchbutton.bind(on_release=self.searchpressed)
self.add_widget(self.searchbutton)
def searchpressed(self, instance):
app = App.get_running_app()
placements = database.child("placements").get()
placementslist = placements.val()
placementslist.items()
for key, value in placementslist.items():
self.key = key
key_list = []
key_list.append(key)
for key in key_list:
name = database.child("placements").child(str(key)).child("placement name").get()
description = database.child("placements").child(str(key)).child("placement description").get()
location = database.child("placements").child(str(key)).child("placement location").get()
date = database.child("placements").child(str(key)).child("placement date").get()
price = database.child("placements").child(str(key)).child("placement price").get()
thelocalId = database.child("placements").child(str(key)).child("localId").get()
self.thelocalId = thelocalId.val()
data = "\n" + "\n" + str(name.val()) + '\n' + str(description.val()) + "\n" + str(
location.val()) + '\n' + str(date.val()) + '\n' + '\n' + str(price.val())
project_list_screen = self.manager.get_screen('project_list_screen')
project_list_screen.project_list.adapter.data.extend(["\n" + "\n" + str(name.val()) + '\n' + str(
description.val()) + "\n" + str(location.val()) + '\n' + str(date.val()) + '\n' + '\n' + str(
price.val())])
project_list_screen.project_list._trigger_reset_populate()
app.root.current = "project_list_screen"
def printtext(self):
self.placementtext = self.project_list_screen.project_list.adapter.selection[0]
Factory.register('MainWindow', cls=MainWindow)
class ApplyPage(Screen):
mainwindow = ObjectProperty(None)
def __init__(self, **kwargs):
self.mainwindow = kwargs.pop('mainwindow', None)
super(ApplyPage, self).__init__(**kwargs)
self.yes = Button(text="Yes", font_size = 20, font_name= "fonts/Qanelas-Heavy.otf", background_color = (0.082, 0.549, 0.984, 1.0), background_normal= '', pos_hint = {"x":0.1,"y":0.05}, size_hint= [0.2, 0.1])
self.add_widget(self.yes)
self.no = Button(text="No", font_size= 20, font_name= "fonts/Qanelas-Heavy.otf", background_color = (0.082, 0.549, 0.984, 1.0), background_normal= '', pos_hint = {"x":0.7, "y":0.05}, size_hint= [0.2, 0.1])
self.add_widget(self.no)
def on_enter(self, *args):
print(self.mainwindow.placementtext)
这是我在kivy文件中实例化课程的方式
ApplyPage:
id: applyingpage
name: "applyingpage"
mainwindow: Factory.MainWindow()
对于如何访问self.placementtext
原始值的任何帮助,将不胜感激
答案 0 :(得分:0)
一种懒惰的方法是为应用程序类提供一个属性,您可以在主屏幕中将信息输入该属性,然后在第二个屏幕中读取。
class MyApp(App):
placementtext = None
因此,只要您更改展示位置文本(由于它不是属性,就不能使用on_placementtext绑定),只需添加
app.placementtext = self.placementtext
,您现在可以通过调用app.placementtext从第二个屏幕访问它。例如:
def on_enter(self, *args):
print(app.placementtext)
另一种方法是使用缓存。首先,您注册缓存
Cache.register('windows')
然后在实例化主窗口时添加它
Cache.add('windows','mainwindow',#putyourmainwindowobjecthere)
现在您可以从任何地方调用它!例如:
def on_enter(self,*args):
print(Cache.get('windows','mainwindow').placementtext)
确保首先从kivy导入模块!
希望有帮助!