Python3 Kivy 多个下拉菜单不工作

Question

我正在尝试在 Kivy 中编写应用程序，但遇到了运行问题。当我添加第二个下拉菜单（称为 NotesDropDown）时，两个下拉菜单都停止工作。

这里是主要代码：

from kivy.app import App
from kivy.uix.widget import Widget
from kivy.uix.stacklayout import StackLayout
from kivy.uix.dropdown import DropDown
from kivy.uix.button import Button

class FileDropDown(DropDown):
    def new(self):
        print('New')

    def open_file(self):
        print('Open')

    def save(self):
        print('Save')

    def save_as(self):
        print('Save As')

class NotesDropDown(DropDown):
    def judges(self):
        print('Judges')

    def clubs(self):
        print('Clubs')

    def locations(self):
        print('Locations')

class AgilityApp(App):
    def build(self):
        root_widget = StackLayout(orientation='lr-tb')

        fdd = FileDropDown()
        fbutton = Button(text='File', size_hint=(None, None),
            size=(60,35))
        fbutton.bind(on_release=fdd.open)
        root_widget.add_widget(fbutton)

        ndd = NotesDropDown()
        nbutton = Button(text='Notes', size_hint=(None, None),
            size=(80,35))
        nbutton.bind(on_release=ndd.open)
        root_widget.add_widget(nbutton)

        return root_widget

AgilityApp().run()

kv文件是

<FileDropDown>:
    Button:
        id: new
        text: 'New'
        size_hint_y: None
        height: 35
        on_release: root.new()
    Button:
        id: open
        text: 'Open'
        size_hint_y: None
        height: 35
        on_release: root.open_file()
    Button:
        id: save
        text: 'Save'
        size_hint_y: None
        height: 35
        on_release: root.save()
    Button:
        id: save_as
        text: 'Save As'
        size_hint_y: None
        height: 35
        on_release: root.save_as()

<NotesDropDown>:
    Button:
        id: judges
        text: 'Judges'
        size_hint_y: None
        height: 35
        on_release: root.judges()
    Button:
        id: clubs
        text: 'Clubs'
        size_hint_y: None
        height: 35
        on_release: root.clubs()
    Button:
        id: locations
        text: 'Locations'
        size_hint_y: None
        height: 35
        on_release: root.locations()

我试过将 NotesDropDown 移到离 FileDropDown 更远的地方，加宽它，将布局更改为 BoxLayout、GridLayout 和其他几个都没有成功。

我会说我可以在 Tkinter 中很好地工作，但我希望使用 kivy 以便我也可以将它制作成移动应用程序。

提前致谢！

Answer 1

我怀疑问题出在垃圾回收上。由于您没有持有对 DropDowns 的引用，因此它们被垃圾收集，然后 Buttons 什么都不做。尝试像这样保存对 DropDowns 的引用：

class AgilityApp(App):
    def build(self):
        Builder.load_string(kv)
        root_widget = StackLayout(orientation='lr-tb')

        self.fdd = FileDropDown()  # save a reference avoid garbage collection
        fbutton = Button(text='File', size_hint=(None, None),
            size=(60,35))
        fbutton.bind(on_release=self.fdd.open)
        root_widget.add_widget(fbutton)

        self.ndd = NotesDropDown()  # save a reference avoid garbage collection
        nbutton = Button(text='Notes', size_hint=(None, None),
            size=(80,35))
        nbutton.bind(on_release=self.ndd.open)
        root_widget.add_widget(nbutton)

        return root_widget

Python3 Kivy 多个下拉菜单不工作

Python3 Kivy Multiple DropDown Menus not working

python

python-3.x

kivy

drop-down-menu