在kivy中添加下拉项之间的间距

Question

我的问题是在访问DropDown的container属性，默认情况下它是GridLayout并且包含它的子项。

简单的应用程序：

from kivy.app import App 

from kivy.uix.boxlayout import BoxLayout 
from kivy.uix.dropdown import DropDown 
from kivy.uix.button import Button 
from kivy.uix.label import Label 


class TestApp(App): 
    def build(self): 
     root = BoxLayout(orientation='vertical') 
     dropdown = DropDown() 

     for i in range(3): 
      dropdown.add_widget(Button(
       text=str(i), 
       size_hint_y=None 
      )) # add 3 buttons to dropdown 

     dropdown.container.bind(spacing=8) # this line does not work 

     dropdown_button = Button(size_hint_y=.2, text='Open DropDown') 
     dropdown_button.bind(on_release=dropdown.open) 

     root.add_widget(dropdown_button) 
     root.add_widget(Label()) # empty space under button 
     return root 

TestApp().run() 

我尝试使用bind方法这一点，但没有结果。没有设置缩进。我也希望在kivy语言中看到解决方案，因为我想使用dp()函数来设置间距，并且为此将参数传递给python文件不太方便。预先感谢您的帮助。

Answer 1

而不是使用bind你应该直接设定值：

from kivy.app import App 

from kivy.uix.boxlayout import BoxLayout 
from kivy.uix.dropdown import DropDown 
from kivy.uix.button import Button 
from kivy.uix.widget import Widget 


class TestApp(App): 
    def build(self): 
     root = BoxLayout(orientation='vertical') 
     dropdown = DropDown() 

     for i in range(3): 
      dropdown.add_widget(Button(
       text=str(i), 
       size_hint_y=None 
      )) # add 3 buttons to dropdown 

     dropdown.container.spacing = 10 
     dropdown.container.padding = (0, 10, 0, 0) 

     dropdown_button = Button(size_hint_y=.2, text='Open DropDown') 
     dropdown_button.bind(on_release=dropdown.open) 

     root.add_widget(dropdown_button) 
     root.add_widget(Widget()) # empty space under button 
     return root 

TestApp().run() 

使用自定义容器类不直接支持。你可以像这样做，但它的哈克和丑陋：

from kivy.app import App 

from kivy.uix.boxlayout import BoxLayout 
from kivy.uix.gridlayout import GridLayout 
from kivy.uix.dropdown import DropDown 
from kivy.uix.button import Button 
from kivy.uix.widget import Widget 

from kivy.lang import Builder 

Builder.load_string(''' 
<MyContainer>: 
    # copied from kivy.uix.dropdown._grid_kv 
    size_hint_y: None 
    height: self.minimum_size[1] 
    cols: 1 
    # custom settings 
    spacing: 10 
    padding: (0, 10, 0, 0) 
''') 

class MyContainer(GridLayout): 
    pass 


class TestApp(App): 
    def build(self): 
     root = BoxLayout(orientation='vertical') 

     container = MyContainer() 
     dropdown = DropDown(container=container) 
     super(DropDown, dropdown).add_widget(container) 
     dropdown.on_container(dropdown, container) 

     for i in range(3): 
      dropdown.add_widget(Button(
       text=str(i), 
       size_hint_y=None 
      )) # add 3 buttons to dropdown 

     dropdown_button = Button(size_hint_y=.2, text='Open DropDown') 
     dropdown_button.bind(on_release=dropdown.open) 

     root.add_widget(dropdown_button) 
     root.add_widget(Widget()) # empty space under button 
     return root 

TestApp().run() 

所以我要说它会更加清洁，使自定义间隔类作为控件的子类按钮之间填充空间：

from kivy.app import App 

from kivy.uix.boxlayout import BoxLayout 
from kivy.uix.dropdown import DropDown 
from kivy.uix.button import Button 
from kivy.uix.widget import Widget 

from kivy.lang import Builder 

Builder.load_string(''' 
<DropDownSpacing>: 
    size_hint_y: None 
    height: 20 
''') 

class DropDownSpacing(Widget): 
    pass 


class TestApp(App): 
    def build(self): 
     root = BoxLayout(orientation='vertical') 
     dropdown = DropDown() 

     for i in range(3): 
      dropdown.add_widget(DropDownSpacing()) 

      dropdown.add_widget(Button(
       text=str(i), 
       size_hint_y=None 
      )) # add 3 buttons to dropdown 

     dropdown_button = Button(size_hint_y=.2, text='Open DropDown') 
     dropdown_button.bind(on_release=dropdown.open) 

     root.add_widget(dropdown_button) 
     root.add_widget(Widget()) # empty space under button 
     return root 

TestApp().run() 

这与您在主要BoxLayout中所做的一样，除了我更喜欢直接使用Widget类而不是Label而没有文本。