Kivymd：如何在不创建自定义类的情况下在列表项中添加复选框？
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【中文标题】Kivymd：如何在不创建自定义类的情况下在列表项中添加复选框？【英文标题】：Kivymd: How to add checkbox in List item without creating custom class? 【发布时间】：2021-11-22 00:15:43 【问题描述】：如何添加带有 MDList 项目的复选框？在我的项目中，我需要一个事件，“单击按钮后将所选项目文本存储在 python 列表中”。当我为带有复选框的列表创建自定义类时，可以轻松完成（如 kivymd 文档中所示）。
from kivy.lang import Builder
from kivy.properties import StringProperty
from kivymd.app import MDApp
from kivymd.uix.list import IRightBodyTouch, TwoLineAvatarIconListItem
from kivymd.uix.selectioncontrol import MDCheckbox
KV = """
<ListItemWithCheckbox>:
IconLeftWidget:
icon: root.icon
RightCheckbox:
id: cb
BoxLayout:
ScrollView:
MDList:
id: scroll
MDRaisedButton:
text: "Save"
on_release: app.save_checked()
"""
class ListItemWithCheckbox(TwoLineAvatarIconListItem):
"""Custom list item."""
icon = StringProperty("android")
class RightCheckbox(IRightBodyTouch, MDCheckbox):
"""Custom right container."""
class MainApp(MDApp):
def build(self):
return Builder.load_string(KV)
def on_start(self):
for i in range(15):
self.root.ids.scroll.add_widget(
ListItemWithCheckbox(text=f"Item i", secondary_text=f"Item i+10", icon='User_images/s.jpg')
)
def save_checked(self):
mdlist = self.root.ids.scroll # get reference to the MDList
selected_item = []
for wid in mdlist.children:
if isinstance(wid, ListItemWithCheckbox): # only interested in the ListItemWithCheckboxes
cb = wid.ids.cb # use the id defined in kv
if cb.active: # only append selected items
selected_item.append(wid.text)
selected_item = selected_item[::-1]
print(selected_item)
MainApp().run()
当我尝试使用屏幕管理器（用于处理多个屏幕）应用这个东西时，它不起作用。我可以在不为列表创建自定义类的情况下创建带有复选框的列表吗？
注意：我的要求是，我需要一个带有复选框的列表。按下按钮选择列表项后，应打印所选项目（或用于其他目的）
【问题讨论】：
【参考方案1】：为了在没有自定义类的情况下做到这一点，请使用答案末尾的示例：
from kivy.lang import Builder
from kivy.properties import StringProperty
from kivymd.app import MDApp
from kivymd.uix.list import IRightBodyTouch, TwoLineAvatarIconListItem
from kivymd.uix.selectioncontrol import MDCheckbox
KV = """
<CB@TwoLineAvatarIconListItem>:
IconLeftWidget:
id: i1
icon: "pencil" #root.icon
IconRightWidget:
icon: "a11.png" #this is a transparent png image of 188 bytes
MDCheckbox:
id: x54
on_active:
app.save_checked(*args,root.text,root.secondary_text,root.ids.i1.icon,root)
BoxLayout:
ScrollView:
MDList:
id: scroll
#for i in range(15)#
CB:
text: "Hello"
secondary_text: "Two"
icon: "pencil"
CB:
text: "Hello jbsidis"
secondary_text: "Two"
icon: "pencil"
CB:
text: "Hello"
secondary_text: "Two"
icon: "pencil"
CB:
text: "Hello"
secondary_text: "Two"
icon: "pencil"
CB:
text: "Hello"
secondary_text: "Two"
icon: "pencil"
CB:
text: "Josue Carranza"
secondary_text: "jbsidis"
icon: "pencil"
CB:
text: "Hello"
secondary_text: "Two"
icon: "pencil"
CB:
text: "Hello"
secondary_text: "Two"
icon: "pencil"
CB:
text: "Hello"
secondary_text: "Two"
icon: "pencil"
CB:
text: "Hello"
secondary_text: "Two"
icon: "pencil"
CB:
text: "Hello"
secondary_text: "Two"
icon: "pencil"
CB:
text: "Hello"
secondary_text: "Two"
icon: "pencil"
CB:
text: "Hello"
secondary_text: "Two"
icon: "pencil"
CB:
text: "Hello"
secondary_text: "Two"
icon: "pencil"
CB:
text: "Hello"
secondary_text: "Two"
icon: "pencil"
MDRaisedButton:
id: cm
text: "Save"
on_release: app.save_checked()
"""
selected_item = []
class MainAppjbsidis(MDApp):
def build(self):
return Builder.load_string(KV)
def save_checked(self,checkbox, value,a,b,c,w):
mmm="""
You clicked on: Josue Carranza jbsidis
Selected Items 4: [[<WeakProxy to <kivy.factory.CB object at 0x7efc032f4430>>], [<WeakProxy to <kivy.factory.CB object at 0x7efc032f4430>>], [<WeakProxy to <kivy.factory.CB object at 0x7efc0324d9e0>>], [<WeakProxy to <kivy.factory.CB object at 0x7efc03137b30>>]]
"""
if value:
print('The checkbox is active', 'and', checkbox.state, 'state')
global selected_item
if len(selected_item)==0:
selected_item = []
selected_item.append([w])
print("\n\nYou clicked on: ",a,b,c)
print("Selected Items "+str(len(selected_item))+": "+str(selected_item))
if len(selected_item)>0:
selected_item.append([w])
print("\n\nYou clicked on: ",a,b,c)
print("Selected Items "+str(len(selected_item))+": "+str(selected_item))
self.root.ids.cm.text="Save "+str(len(selected_item))
else:
print('\n\nThe checkbox is inactive', 'and', checkbox.state, 'state')
new_list=[]
if len(selected_item)>0:
for x in selected_item:
if x==w:
pass
if x!=w:
new_list=new_list+[w]
selected_item=new_list
print("\n\nNew Items: "+str(selected_item))
MainAppjbsidis().run()
图片：
如果您不想拥有任何自定义类，例如：
<CB@TwoLineAvatarIconListItem>:
IconLeftWidget:
id: i1
icon: "pencil" #root.icon
IconRightWidget:
icon: "a11.png" #this is a transparent png image of 188 bytes
MDCheckbox:
id: x54
on_active:
app.save_checked(*args,root.text,root.secondary_text,root.ids.i1.icon,root)
你应该使用 do it with:
from kivy.lang import Builder
from kivy.properties import StringProperty
from kivymd.app import MDApp
from kivymd.uix.list import IRightBodyTouch, TwoLineAvatarIconListItem
from kivymd.uix.selectioncontrol import MDCheckbox
KV = """
BoxLayout:
ScrollView:
MDList:
id: scroll
#for i in range(15)#
TwoLineAvatarIconListItem:
id: mm1
text: "Hello"
secondary_text: "Two"
icon: "pencil"
IconLeftWidget:
id: i1
icon: "pencil" #root.icon
IconRightWidget:
icon: "a11.png" #this is a transparent png image of 188 bytes
MDCheckbox:
id: x54
on_active:
app.save_checked(*args,root.ids.mm1.text,root.ids.mm1.secondary_text,root.ids.i1.icon,root)
TwoLineAvatarIconListItem:
id: mm2
text: "Hello"
secondary_text: "Two"
icon: "pencil"
IconLeftWidget:
id: i1
icon: "pencil" #root.icon
IconRightWidget:
icon: "a11.png" #this is a transparent png image of 188 bytes
MDCheckbox:
id: x54
on_active:
app.save_checked(*args,root.ids.mm2.text,root.ids.mm2.secondary_text,root.ids.i1.icon,root)
TwoLineAvatarIconListItem:
id: mm3
text: "Hello"
secondary_text: "Two"
icon: "pencil"
IconLeftWidget:
id: i1
icon: "pencil" #root.icon
IconRightWidget:
icon: "a11.png" #this is a transparent png image of 188 bytes
MDCheckbox:
id: x54
on_active:
app.save_checked(*args,root.ids.mm3.text,root.ids.mm3.secondary_text,root.ids.i1.icon,root)
TwoLineAvatarIconListItem:
id: mm4
text: "Hello"
secondary_text: "Two"
icon: "pencil"
IconLeftWidget:
id: i1
icon: "pencil" #root.icon
IconRightWidget:
icon: "a11.png" #this is a transparent png image of 188 bytes
MDCheckbox:
id: x54
on_active:
app.save_checked(*args,root.ids.mm4.text,root.ids.mm4.secondary_text,root.ids.i1.icon,root)
TwoLineAvatarIconListItem:
id: mm5
text: "Hello"
secondary_text: "Two"
icon: "pencil"
IconLeftWidget:
id: i1
icon: "pencil" #root.icon
IconRightWidget:
icon: "a11.png" #this is a transparent png image of 188 bytes
MDCheckbox:
id: x54
on_active:
app.save_checked(*args,root.ids.mm5.text,root.ids.mm5.secondary_text,root.ids.i1.icon,root)
TwoLineAvatarIconListItem:
id: mm6
text: "Hello"
secondary_text: "Two"
icon: "pencil"
IconLeftWidget:
id: i1
icon: "pencil" #root.icon
IconRightWidget:
icon: "a11.png" #this is a transparent png image of 188 bytes
MDCheckbox:
id: x54
on_active:
app.save_checked(*args,root.ids.mm6.text,root.ids.mm6.secondary_text,root.ids.i1.icon,root)
MDRaisedButton:
id: cm
text: "Save"
on_release: app.save_checked()
"""
selected_item = []
class MainAppjbsidis(MDApp):
def build(self):
return Builder.load_string(KV)
def save_checked(self,checkbox, value,a,b,c,w):
mmm="""
You clicked on: Josue Carranza jbsidis
Selected Items 4: [[<WeakProxy to <kivy.factory.CB object at 0x7efc032f4430>>], [<WeakProxy to <kivy.factory.CB object at 0x7efc032f4430>>], [<WeakProxy to <kivy.factory.CB object at 0x7efc0324d9e0>>], [<WeakProxy to <kivy.factory.CB object at 0x7efc03137b30>>]]
"""
if value:
print('The checkbox is active', 'and', checkbox.state, 'state')
global selected_item
if len(selected_item)==0:
selected_item = []
selected_item.append([w])
print("\n\nYou clicked on: ",a,b,c)
print("Selected Items "+str(len(selected_item))+": "+str(selected_item))
if len(selected_item)>0:
selected_item.append([w])
print("\n\nYou clicked on: ",a,b,c)
print("Selected Items "+str(len(selected_item))+": "+str(selected_item))
self.root.ids.cm.text="Save "+str(len(selected_item))
else:
print('\n\nThe checkbox is inactive', 'and', checkbox.state, 'state')
new_list=[]
if len(selected_item)>0:
for x in selected_item:
if x==w:
pass
if x!=w:
new_list=new_list+[w]
selected_item=new_list
print("\n\nNew Items: "+str(selected_item))
MainAppjbsidis().run()
没有客户类的图片：
【讨论】：
编辑：当我输入错误的“客户类”时，我的意思是“自定义类” 谢谢你。但我仍然遇到问题。在实时应用程序中，我需要在 python 文件中创建列表项，然后将所有列表项添加到 .kv 文件中的列表中。你能告诉我解决这个问题的方法吗？注意：尝试在每个列表项中添加复选框时出现错误。 是的，如果您需要将选定的项目移动到新屏幕（到新列表），您应该使用“selected_item”全局变量并将这些选定的项目添加到新的MDList中屏幕，请记住，因为它是一个列表，您可以使用 for 循环将这些选定的项目添加到新屏幕，或者只是将值（而不是现在的小部件）保存为纯文本字符串，然后解析那些在新屏幕中，具体取决于您需要做什么 行 "icon: "a11.png" #this is an transparent png image of 188 bytes" 需要复选框干净并准备好使用，下载一个应该透明的 png 图像 好的，我明白了。如果你能帮助我在这个脚本中实现它，那对我来说会非常好---------> github.com/Shourov1702040/hpylearners_Python/blob/main/…以上是关于Kivymd：如何在不创建自定义类的情况下在列表项中添加复选框？的主要内容，如果未能解决你的问题，请参考以下文章
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