复杂的布局是否可以进行分类，以便在布局中重复使用

Question

我有一个特定的Boxlayout，它包含在一行中显示值的标签；现在有好几行，每一行都是一个矩形布局。我想知道我是否可以制作一个包括所有标签的盒子布局类。因此，当我转到我的.kv文件时，我只需要调用类，而不必重复所有参数。编辑：我已经放置了相应的。千伏

MDBoxLayout:
orientation: 'vertical'
MDToolbar:
title: "My Stock Tickers"

left_action_items: [["menu", lambda x: x]]
type: 'top'
MyBox:
size_hint: None, None
size: 400, 100

pos_hint: {"center_x": 0.5}
#elevation: 20
padding: 25
spacing: 25

md_bg_color: [0, .7, 1, 1]
#Widget:
#size_hint_y : None
#height: 10
MDLabel:
text: "Enter Ticker"
font_size: 15
halign: "center"
size_hint_y: None
height: self.texture_size[1]

MDTextFieldRound:
#id: user
width: 30
font_size: 18
#padding_y: 15
spacing: '20dp'
MDFIconButton:
user_font_size: "15sp"
icon: "plus"
opposite_colors: True
elevation: 8
md_bg_color: 1, 0, 0, 1
spacing: '20dp'

MDLabel:
id: t_price
text: "000.00"
font_size: 15
halign: "center"
size_hint_y: None
height: self.texture_size[1]
padding_y: 10
MDLabel:
id: t_change
text: "00.00"
font_size: 15
halign: "center"
size_hint_y: None
height: self.texture_size[1]
padding_y: 10
MyBox:
size_hint: None, None
size: 400, 200
md_bg_color: [0, .9, 1, 1]
#spacing: 10
orientation: "vertical"
pos_hint: {"center_x": 0.5}


MyBox:                                   # Title Row
size_hint: 1, None
height: 30
Widget:
size_hint_x : None
width: 20
MDLabel:
#color: 72/255,89/255,89/255,1
color: 0,0,0,1
text: "NAME"

halign: 'left'
size_hint: None, 1
width: 100

MDLabel:
color: (0,0,0,1)
text: "Value"
MDLabel:
color: (0,0,0,1)
text: "Change"
MDLabel:
color: (0,0,0,1)
text: "Chg %"

MyRowBox:                                                  #1st Row
id: row1
#self.name.text: "Dow"         ????????
#self.value.text: "000.000"    ????????
#self.change.text: "000.000"   ????????
#self.percnt.text: "0.01%"     ????????

我认为可行的例子是这样的(在python中(：编辑：我放置了一个工作样本

from kivy.lang import Builder
from kivymd.app import MDApp
from kivymd.uix.behaviors import RectangularElevationBehavior
from kivymd.uix.boxlayout import MDBoxLayout
from kivymd.uix.label import MDLabel
from kivymd.uix.textfield import MDTextField
from kivymd.uix.button import MDIconButton
from kivymd.uix.widget import MDWidget
class MDFIconButton(MDIconButton):
pass
class MyBox(MDBoxLayout):
class update():
pass
class MyRowBox(MDBoxLayout):
def __init__(self, **kwargs):
super(MyRowBox, self).__init__(**kwargs)
size_hint= 1, None
height= 30
self.add_widget(MDWidget(size_hint_x= None, width= 20))
self.name = (MDLabel( color= [72 / 255, 89 / 255, 89 / 255, 1],halign= 'left', size_hint=[None, 1],width= 100))
self.add_widget(self.name)
self.value = MDLabel(halign= 'left')
self.add_widget(self.value)
self.change = MDLabel(halign='left')
self.add_widget(self.change)
self.percnt = MDLabel(halign='left')
self.add_widget(self.percnt)
self.name.text = "Dow"
self.value.text = "000.000"
self.change.text = "000.000"
self.percnt.text = "000.000"
self.change.font_size = 12
self.percnt.font_size = 12
self.name.color = [72 / 255, 89 / 255, 89 / 255, 1]
self.value.color = [0, 0, 0, 1]
self.change.color = [0, 0, 0, 1]
self.percnt.color = [0, 0, 0, 1]
print(self)
class MyTextField(MDTextField):
pass
class MainApp(MDApp):
def build(self):
self.theme_cls.theme_style = "Dark"
self.theme_cls.primary_palette = "BlueGray"
return Builder.load_file('MyStocks.kv')

MainApp().run()

因为它不起作用。这是可行的，还是我太乐观了。我还需要为所有标签设置Id。

EDIT：情况是我不知道如何更新值。在python文件中，标签有names，我可以从python文件中寻址(正如您在演示中看到的(。现在，当类在.kv文件中实例化时，完整的布局将得到和id。问题是如何使用布局的id和标签的names来更改标签的值。请记住，布局将被实例化多次。

我事先感谢你在这方面提供的任何帮助。谢谢，雷。

Answer 1

如果我正确理解了您的问题，您只需要一个动态类。使用动态类，您可以创建一个具有或不具有某些属性的对象，这些属性可以在几乎不进行进一步修改的情况下使用。在kvlang中，构建和修改类(之后(更加容易。

首先在python中创建一个具有一些确定性(这里是预先确定的或固定数量的(属性的动态类，如

class MyRowBox(MDBoxLayout):
name = StringProperty("NAME")
value = StringProperty("Value")
change = StringProperty("Change")
percnt = StringProperty("Chg %")

然后在kvlang中设计为

<MyRowBox>:
md_bg_color: [0.5, .7, 0.2, 1]
size_hint_y: None
height: "30dp"
Widget:
size_hint_x : None
width: "20dp"
MDLabel:
color: 72/255,89/255,89/255,1
color: 0,0,0,1
text: root.name
halign: 'left'
size_hint: None, 1
width: "100dp"
MDLabel:
color: (0,0,0,1)
text: root.value
MDLabel:
color: (0,0,0,1)
text: root.change
MDLabel:
color: (0,0,0,1)
text: root.percnt

因此，您在.kv文件中修改的代码现在应该看起来像

MDBoxLayout:
orientation: 'vertical'
MDToolbar:
title: "My Stock Tickers"
left_action_items: [["menu", lambda x: x]]
type: 'top'
MDBoxLayout:
size_hint: None, None
size: "400dp", "100dp"
pos_hint: {"center_x": 0.5}
#elevation: 20
padding: 25
spacing: 25
md_bg_color: [0, .7, 1, 1]
#Widget:
#size_hint_y : None
#height: 10
MDLabel:
text: "Enter Ticker"
font_size: 15
halign: "center"
size_hint_y: None
height: self.texture_size[1]

MDTextFieldRound:
#id: user
width: 30
font_size: 18
#padding_y: 15
spacing: '20dp'
MDFIconButton:
user_font_size: "15sp"
icon: "plus"
opposite_colors: True
elevation: 8
md_bg_color: 1, 0, 0, 1
spacing: '20dp'

MDLabel:
id: t_price
text: "000.00"
font_size: 15
halign: "center"
size_hint_y: None
height: self.texture_size[1]
padding_y: 10
MDLabel:
id: t_change
text: "00.00"
font_size: 15
halign: "center"
size_hint_y: None
height: self.texture_size[1]
padding_y: 10
MyRowBox:    # Same class as a title row
# due to its initilization style.
# Change it if you need to.

MyRowBox:
id: row1
name: "Dow"
value: "000.000"
change: "000.000"
percnt: "0.01%"
MyRowBox:
id: row2
name: "Dow"
value: "000.000"
change: "000.000"
percnt: "0.01%"
MyRowBox:
id: row3
name: "Dow"
value: "000.000"
change: "000.000"
percnt: "0.01%"
MyRowBox:
id: row4
name: "Dow"
value: "000.000"
change: "000.000"
percnt: "0.01%"

<MyRowBox>:
md_bg_color: [0.5, .7, 0.2, 1]
size_hint_y: None
height: "30dp"
Widget:
size_hint_x : None
width: "20dp"
MDLabel:
color: 72/255,89/255,89/255,1
color: 0,0,0,1
text: root.name
halign: 'left'
size_hint: None, 1
width: "100dp"
MDLabel:
color: (0,0,0,1)
text: root.value
MDLabel:
color: (0,0,0,1)
text: root.change
MDLabel:
color: (0,0,0,1)
text: root.percnt

更新(用例(：

这个类在python中的使用情况可能是，

# Please add the rest / necessary blocks.
class MainApp(MDApp):
def build(self):
self.theme_cls.theme_style = "Dark"
self.theme_cls.primary_palette = "BlueGray"
self.root = Builder.load_string(kv)
return self.root

def on_start(self):
box1 = self.root.ids.row1
box2 = self.root.ids.row2
# etc.
for i, box in enumerate([box1, box2, ]):
box.name = str(i+1)
box.value = str(100+i)
box.change = str(i)
box.percnt = f"{i/100:0.2%}"

MainApp().run()

---

注意：

1. 我使用dp以获得更好的一致性。你可以改变它
2. 您可能不再需要MyBox类了