如何在 Kivy 中使用 Popup 运行复选框小部件？

Question

这里是新手 kivy 用户。我已经创建了 2 个 Kivy 应用程序，每个应用程序都可以单独运行，但我无法将一个集成到另一个应用程序中。我正在尝试使用 Popup(onButtonPress3) 在MyApp 中运行CheckBoxesApp。当我运行我的代码时，我收到错误“WidgetException: add_widget() can be used only with instances of the Widget class.”可能与 CheckBoxesApp 使用 App 而 MyApp 使用 MDApp 的事实有关？任何帮助表示赞赏>>

main.py

from kivy.uix.label import Label
from kivy.uix.gridlayout import GridLayout
from kivy.uix.button import Button
from kivy.app import App
from kivy.uix.widget import Widget
import kivy
kivy.require('1.10.1')
from kivymd.app import MDApp
from kivy.uix.popup import Popup


FruitsSellected = []


class Checkboxes(Widget):

  def checkboxes_click(self, instance, value, text):
    if value:
      print(f"Select {text}")
      self.myvar = FruitsSellected
      #Close
      if text == 'FINISH':
        print(FruitsSellected)
        self.save()
        App.get_running_app().stop()
        return FruitsSellected

      FruitsSellected.append(str(text))

    else:
      print(f"UnSelect {text}")
      FruitsSellected.remove(str(text))

  def save(self):
    with open("allergenlist.txt", "w") as fobj:
      fobj.write(str(self.myvar))




class CheckBoxesApp(App):
  def build(self):
    return Checkboxes()


class MyApp(MDApp):

    def build(self):
        # Define a grid layout for this App
        self.layout = GridLayout(cols=1, padding=10)

        # Don't worry about this button, just a place holder
        self.button = Button(text="TAKE PICTURE")
        self.layout.add_widget(self.button)
        # Add a button
        self.button2 = Button(text="SELECT")
        self.layout.add_widget(self.button2)        # Add a button

        # Attach a callback for the button press event
        self.button.bind(on_press=self.onButtonPress)
        self.button2.bind(on_press=self.onButtonPress3)

        return self.layout

    #Place Holder don't worry about this either
    def onButtonPress(self, button):

        layout = GridLayout(cols=1, padding=10)

        popupLabel = Label(text="TAKE PICTURE")
        closeButton = Button(text="Close the pop-up")

        layout.add_widget(popupLabel)
        layout.add_widget(closeButton)

        # Instantiate the modal popup and display
        popup = Popup(title='TAKE PICTURE',
                      content=layout)
        popup.open()

        # Attach close button press
        closeButton.bind(on_press=popup.dismiss)



    def onButtonPress3(self, button):


        layout = CheckBoxesApp()
        popup3 = Popup(title='SELECT', content=layout)
        popup3.open()


if __name__ == '__main__':
    MyApp().run()

Checkboxes.kv

<Checkboxes>

  # Create Box Layout
  BoxLayout:
    # set orientation and size
    orientation: "vertical"
    size: root.width, root.height

    # Creating label


    # create Grid Layout
    GridLayout:
      # Set number of column
      cols:4

      # create checkboxes
      Label:
        text: "Apple"

      CheckBox:
        # When check box selected, it will call checkboxes_click() method
        on_active: root.checkboxes_click(self, self.active, "Apple")

      Label:
        text: "Bannana"

      CheckBox:
        on_active: root.checkboxes_click(self, self.active, "Bannana")

      Label:
        text: "Orange"

      CheckBox:
        on_active: root.checkboxes_click(self, self.active, "Orange")

      Label:
        text: "Grape"

      CheckBox:
        on_active: root.checkboxes_click(self, self.active, "Grape")

      Label:
        text: "Melon"

      CheckBox:
        on_active: root.checkboxes_click(self, self.active, "Melon")

      Label:
        text: "Peach"

      CheckBox:
        on_active: root.checkboxes_click(self, self.active, "Peach")

      Label:
        text: "Pineapple"

      CheckBox:
        on_active: root.checkboxes_click(self, self.active, "Pineapple")

      Label:
        text: "FINISH"

      CheckBox:
        on_active: root.checkboxes_click(self, self.active, "FINISH")

Answer 1

Popup 的content 必须是Widget，但App 不是Widget，所以你的代码：

def onButtonPress3(self, button):
    layout = CheckBoxesApp()
    popup3 = Popup(title='SELECT', content=layout)
    popup3.open()

会失败。

我建议将该代码更改为：

def onButtonPress3(self, button):
    # layout = CheckBoxesApp()
    layout = Checkboxes()
    popup3 = Popup(title='SELECT', content=layout)
    popup3.open()

当然，您必须明确加载 Checkboxes.kv 文件才能使其工作。