Kivy如何在GridLayout中创建下拉列表 [英] Kivy how to create dropdownlist within a GridLayout

问题描述

我有2个文件，其中一个 py 和另一个 kv ，正如标题所述，我不知道如何添加下拉列表.

I have 2 files one of the py and the other kv, well as the title says, I do not know how to add a dropdown.

---> main.py

---> main.py

from kivy.app import App
from kivy.uix.dropdown import DropDown
from kivy.uix.gridlayout import GridLayout

class MyGridLayout(GridLayout):
    pass

class LayoutsApp(App):
    def build(self):
        return MyGridLayout()


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

---> layouts.kv

---> layouts.kv

<MyGridLayout>:
    rows: 2
    id: main_win
    Dropdown:
        id: dropdown
        Button:
            id: btn1
            text: 'option 1'
        Button:
            id: btn2
            text: 'option 2'
    BoxLayout:

    BoxLayout:

编译时，它会为该部分生成错误.打电话给下拉列表的正确方法是什么?

when compiling, it generates error for that part. How is the correct way to make the call for dropdown-list?

推荐答案

问题3

调用Button id:btn2，我该怎么做? -我的意思是:上课 MyGridLayout(GridLayout):

call the Button id: btn2, how would I do it? - I mean:class MyGridLayout(GridLayout):

解决方案3

Python脚本

• 添加导入语句:from kivy.uix.dropdown import DropDown; from kivy.properties import ObjectProperty
• 实施class CustomDropDown(DropDown):
• 在MyGridLayout类中，在类级别声明一个ObjectProperty(例如，dropdown = ObjectProperty(None)；实现方法dropdown_open(self):；实例化CustomDropDown类并将其分配给self.dropdown，依此类推.有关详细信息，请参阅代码片段.)

Solution 3

Python script

• Add import statements: from kivy.uix.dropdown import DropDown; from kivy.properties import ObjectProperty
• Implement class CustomDropDown(DropDown):
• In class MyGridLayout, declare an ObjectProperty at class level (e.g. dropdown = ObjectProperty(None); implement a method dropdown_open(self):; instantiate the class CustomDropDown and assigned it to self.dropdown, etc. Please refer to snippets for detail.
• 删除self.dismiss()
• 将动态类<CustomDropdown@DropDown>:替换为类规则<CustomDropDown>:
• 将rows: 2替换为rows: 3
• 将Factory.CustomDropdown().open(self)替换为root.dropdown_open(self)
• Remove self.dismiss()
• Replace dynamic class, <CustomDropdown@DropDown>: with class rule, <CustomDropDown>:
• Replace rows: 2 with rows: 3
• Replace Factory.CustomDropdown().open(self) with root.dropdown_open(self)

from kivy.uix.dropdown import DropDown
from kivy.properties import ObjectProperty


class CustomDropDown(DropDown):
    pass


class MyGridLayout(GridLayout):
    dropdown = ObjectProperty(None)

    def dropdown_open(self, instance):
        self.dropdown = CustomDropDown()
        self.dropdown.open(instance)
        print(self.dropdown.ids.btn2.text)

layouts.kv-片段

<CustomDropDown>:
    id: dropdown
    on_select:
        app.root.ids.btn.text = '{}'.format(args[1])
...
<MyGridLayout>:
    rows: 3
    id: main_win

    Button:
        id: btn
        text: 'Press'
        size_hint_y: None
        height: '48dp'
        on_release:
            root.dropdown_open(self)

输出3

当我添加这些命令时，它不起作用:BoxLayout:方向: 'vertical'size_hint:(.9，.9)BoxLayout:方向:'vertical' size_hint_y:0.5

when I added these commands, it does not work: BoxLayout: orientation: 'vertical' size_hint: (.9,.9) BoxLayout: orientation: 'vertical' size_hint_y: 0.5

注意

您可能需要将行从2增加到3.

• 为两个BoxLayout添加了配置
• 为说明起见，为两个BoxLayout的画布添加了颜色

#:kivy 1.10.1
#:import Factory kivy.factory.Factory

<CustomDropdown@DropDown>:
    id: dropdown
    on_select:
        app.root.ids.btn.text = '{}'.format(args[1])
        self.dismiss()

    Button:
        id: btn1
        text: 'option 1'
        size_hint_y: None
        height: '48dp'
        on_release:
            dropdown.select(btn1.text)

    Button:
        id: btn2
        text: 'option 2'
        size_hint_y: None
        height: '48dp'
        on_release:
            dropdown.select(btn2.text)

<MyGridLayout>:
    rows: 2
    id: main_win

    Button:
        id: btn
        text: 'Press'
        on_release: Factory.CustomDropdown().open(self)
        size_hint_y: None
        height: '48dp'

    BoxLayout:
        orientation: 'vertical'
        size_hint: (.9,.9)
        canvas.before:
            Color:
                rgba: 1, 0, 0, 1    # red
            Rectangle:
                pos: self.pos
                size: self.size

    BoxLayout:
        orientation: 'vertical'
        size_hint_y: 0.5
        canvas.before:
            Color:
                rgba: 0, 0, 1, 1    # blue
            Rectangle:
                pos: self.pos
                size: self.size

输出#2

Output #2

DropDown小部件类似于Popup小部件，即它们是特殊的小部件.

DropDown widget is like Popup widget i.e. they are special widget.

Popup/DropDown是一个特殊的小部件.请勿尝试将其作为孩子添加到其他任何孩子中 小部件.如果您这样做，将像普通小部件一样处理Popup/DropDown，并且 不会隐藏在后台.

Popup / DropDown is a special widget. Don’t try to add it as a child to any other widget. If you do, Popup / DropDown will be handled like an ordinary widget and won’t be created hidden in the background.

因此，创建一个具有DropDown小部件继承的动态类，并使用Factory实例化该类.

Therefore, create a dynamic class with inheritance of DropDown widget, and use Factory to instantiate the class.

from kivy.app import App
from kivy.uix.gridlayout import GridLayout


class MyGridLayout(GridLayout):
    pass


class LayoutsApp(App):
    def build(self):
        return MyGridLayout()


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

layouts.kv

#:kivy 1.10.1
#:import Factory kivy.factory.Factory

<CustomDropdown@DropDown>:
    id: dropdown
    on_select:
        app.root.ids.btn.text = '{}'.format(args[1])
        self.dismiss()

    Button:
        id: btn1
        text: 'option 1'
        size_hint_y: None
        height: '48dp'
        on_release:
            dropdown.select(btn1.text)

    Button:
        id: btn2
        text: 'option 2'
        size_hint_y: None
        height: '48dp'
        on_release:
            dropdown.select(btn2.text)

<MyGridLayout>:
    rows: 2
    id: main_win

    Button:
        id: btn
        text: 'Press'
        on_release: Factory.CustomDropdown().open(self)
        size_hint_y: None
        height: '48dp'

    BoxLayout:

    BoxLayout:

输出

Output

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