Question

我做了一些研究，但我无法创建一个递归下拉按钮。我想有1个DropDown包含2个包含2个按钮的child-DropDowns，如下所示： DropDown（DropDown（Button，Button），DropDown（Button，Button）） 。这是我的代码，它不起作用（ TypeError：__ init __（）缺少1个必需的位置参数：'screen_manager' ）

的.py：

from kivy.app import App
from kivy.uix.dropdown import DropDown
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.lang import Builder
from kivy.properties import StringProperty


class MyScreenManager(ScreenManager):
    button_text = StringProperty('Show possibilities')

    def __init__(self, **kwargs):
        super(MyScreenManager, self).__init__(**kwargs)
        self.dropdown1 = CustomDropDown1(self)
        self.dropdown2 = CustomDropDown2(self)

    def open_drop_down(self, widget):
        self.dropdown1.open(widget)

class MyScreen(Screen):
    def __init__(self, **kwargs):
        super(MyScreen, self).__init__(**kwargs)

class CustomDropDown1(DropDown):
    def __init__(self, screen_manager, **kwargs):
        super(CustomDropDown1, self).__init__(**kwargs)
        self.sm = screen_manager

    def on_select(self, data):
        self.sm.button_text = data

class CustomDropDown2(DropDown):
    def __init__(self, screen_manager, **kwargs):
        super(CustomDropDown2, self).__init__(**kwargs)
        self.sm = screen_manager

    def on_select(self, data):
        self.sm.button_text = data



Builder.load_file("debug.kv")

class MyAppli(App):
    def build(self):
        return MyScreenManager()

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

.kv：

<MyScreenManager>:

    MyScreen:

        AnchorLayout:

            anchor_y: "top"
            anchor_x: "center"

            Button:

                text: root.button_text
                size:(200,50)
                size_hint:(None,None)
                on_release: root.open_drop_down(self)

<CustomDropDown2>:

    Button:
        text:"Item 1"
        size:(200,50)
        size_hint:(None,None)
        on_release: root.select("ONE")
    Button:
        text:"Item 2"
        size:(200,50)
        size_hint:(None,None)
        on_release: root.select("TWO")
    Button:
        text:"Item 3"
        size:(200,50)
        size_hint:(None,None)
        on_release: root.select("THREE")



<CustomDropDown1>:

    CustomDropDown2:
    CustomDropDown2:

Answer 1

在你的“debug.py”中文件，添加一个CustomDropDown类和一个＆＃39; open_drop_down（）＆＃39;方法：

from kivy.app import App
from kivy.uix.dropdown import DropDown
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.lang import Builder
from kivy.properties import StringProperty


class MyScreenManager(ScreenManager):
    button_text = StringProperty('Show possibilities')

    def __init__(self, **kwargs):
        super(MyScreenManager, self).__init__(**kwargs)
        self.dropdown = CustomDropDown(self)

    def open_drop_down(self, widget):            
        self.dropdown.open(widget)

class MyScreen(Screen):
    def __init__(self, **kwargs):
        super(MyScreen, self).__init__(**kwargs)

class CustomDropDown(DropDown):
    def __init__(self, screen_manager, **kwargs):
        super(CustomDropDown, self).__init__(**kwargs)
        self.sm = screen_manager

    def on_select(self, data):
        self.sm.button_text = data

Builder.load_file("debug.kv")

class MyAppli(App):
    def build(self):
        return MyScreenManager()

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

然后修改您的＆＃39; debug.kv＆＃39;文件使用CustomDropDown：

<MyScreenManager>:

    MyScreen:

        BoxLayout:

            Button:

                text: root.button_text
                size:(200,50)
                size_hint:(None,None)
                on_release: root.open_drop_down(self)

<CustomDropDown>:
    Button:
        text:"Item 1"
        size:(200,50)
        size_hint:(None,None)
        on_release: root.select("ONE")
    Button:
        text:"Item 2"
        size:(200,50)
        size_hint:(None,None)
        on_release: root.select(self.text)
    Button:
        text:"Item 3"
        size:(200,50)
        size_hint:(None,None)
        on_release: root.select("THREE")

DropDown菜单将附加到传递给open()方法的小部件，因此在这种情况下，它附加到＆＃34;显示可能性＆＃34;按钮＆＃34;

Kivy：如何实现递归下拉按钮？

1 个答案: