如何在单独的窗口中添加滚动视图？

Question

我想在一个屏幕内和同一屏幕上添加一个滚动视图。我想有一个重定向到主屏幕的按钮。下面显示的代码似乎无效。这是我的python代码（假设我已经导入了相关模块）：

class Main(Screen):
    pass
class View(Screen):
    view = ObjectProperty(Non    
   def __init__(self, **kwargs):
        super(View, self).__init__(**kwargs)
        Clock.schedule_once(self.create_scrollview)

    def create_scrollview(self, dt):
        base = ["element {}".format(i) for i in range(40)]
        layout = GridLayout(cols=1, spacing=10, size_hint_y=None)
        layout.bind(minimum_height=layout.setter("height"))

        for element in base:
            layout.add_widget(Button(text=element, size=(50, 50), size_hint=(1, None),background_color=(0.5, 0.5, 0.5, 1), color=(1, 1, 1, 1)))
        scrollview = ScrollView(size_hint=(1, None), size=(Window.width, Window.height))
        scrollview.add_widget(layout)
        self.view.add_widget(scrollview)

class Manager(ScreenManager): #transition of windows
    def __init__(self, **kwargs):
        super(Manager, self).__init__(**kwargs)
    pass
kv = Builder.load_file('main.kv')
class NotesApp(App):
    def build(self):
        return kv   
if __name__ == '__main__':
    NotesApp().run()

这是我的kv文件：

Manager:
    Main:
    View:

<Button>:
    font_size:35
<Label>:
    font_size:45
<Main>:
    name:'main'
<View>:
    name: 'view'
    FloatLayout: 
        Button:
            pos_hint:{'x':0.2,'top':0.975}
            size_hint:0.6,0.15
            text: 'Back'
            on_release:
                app.root.current = 'main'
                root.manager.transition.direction = 'right'

Answer 1

kv文件

• 将id: view添加到FloatLayout:
• 根据课程规则view: view添加<View>:。这是将ObjecProperty连接到ID。
• 将id: btn_view添加到Button:
• 在切换屏幕之前先设置过渡方向

kv-代码段

<View>:
    name: 'view'
    view: view

    FloatLayout:
        id: view

        Button:
            id: btn_view
            pos_hint: {'x':0.2, 'top':0.975}
            size_hint: 0.6, 0.15
            text: 'Back'
            on_release:
                root.manager.transition.direction = 'right'
                root.manager.current = 'main'

Python脚本

• 用Button小部件的高度减去ScrollView的高度

Python-代码段

        scrollview = ScrollView(size_hint=(1, None), size=(Window.width, Window.height - self.ids.btn_view.height),
                                bar_width=8, bar_color=[1, 0, 0, 1], bar_inactive_color=[0, 0, 1, 1],
                                effect_cls="ScrollEffect", scroll_type=['bars'])

输出