python kivy 在矩形内添加文本

Question

如何在矩形内添加文本？我正在使用下面的代码并在 Canvas 内添加了一个标签，希望它会显示在矩形内。

import kivy
from kivy.app import App
from kivy.uix.anchorlayout import AnchorLayout
from kivy.uix.gridlayout import GridLayout
from kivy.uix.label import Label
from kivy.uix.video import Video
from kivy.uix.relativelayout import RelativeLayout
from kivy.graphics import *

class MyApp(App):
    def build(self):
        r = AnchorLayout()
        f = RelativeLayout()
        g = GridLayout(cols=3, rows=5)
        v = Video(source='driver.mp4', state='play', options={'eos':'loop'})
        l1 = Label(text="jenkins", font_size=32)
        l2 = Label(text="git", font_size=32)
        f.add_widget(v)
        f.add_widget(g)
        g.add_widget(l1)
        g.add_widget(l2)
        with g.canvas:
            Color(.4, .1, .1)
            Rectangle(pos=(100,10), size=(100,100))
            Label(text="KSHK")
        return f

if __name__ == "__main__":
    MyApp().run()

更新: 这不会在 ColoredLabel 的中心对齐文本

import kivy
from kivy.app import App
from kivy.uix.anchorlayout import AnchorLayout
from kivy.uix.gridlayout import GridLayout
from kivy.uix.label import Label
from kivy.uix.video import Video
from kivy.uix.relativelayout import RelativeLayout
from kivy.graphics import *
from kivy.lang import Builder
from kivy.uix.boxlayout import BoxLayout
from random import random
from kivy.properties import ListProperty


kv = '''
<ColoredLabel>:
    background_color:
    canvas.before:
        Color:
            rgba: self.background_color
        Rectangle:
            pos: (10,10)
            size: (100,100)
    '''

Builder.load_string(kv)

class ColoredLabel(Label):
    background_color = ListProperty((0,0,0,1))

class MyApp(App):
    def build(self):
        f = AnchorLayout()
        g = GridLayout(cols=2, rows=2)
        layout = BoxLayout(size_hint=(1, None), height=50)
        v = Video(source='driver.mp4', state='play', options={'eos':'loop'})
        l1 = Label(text="jenkins", font_size=32)
        l2 = Label(text="git", font_size=32)
        f.add_widget(v)


        label = ColoredLabel(text="Hello World!", background_color=(random(), random(), random(), 1))
        g.add_widget(label)


        f.add_widget(g)

        return f

if __name__ == "__main__":
    MyApp().run()

Answer 1

使用具有自定义背景颜色的 Label，然后将其放置在您的布局中。例如:

from kivy.uix.label import Label
from kivy.uix.boxlayout import BoxLayout
from kivy.properties import ListProperty
from kivy.app import App
from kivy.lang import Builder

from random import random

kv = '''
<ColoredLabel>:
    background_color:
    canvas.before:
        Color:
            rgba: self.background_color
        Rectangle:
            pos: self.pos
            size: self.size
'''

Builder.load_string(kv)

class ColoredLabel(Label):
    background_color = ListProperty((0, 0, 0, 1))

class TestApp(App):
    def build(self):
        layout = BoxLayout(size_hint=(1, None), height=50)
        for label in ('a', 'b', 'c', 'd'):
            label = ColoredLabel(text=label, background_color=(random(), random(), random(), 1))
            layout.add_widget(label)

        return layout

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

更新

修复 OP 的问题:

import kivy
from kivy.app import App
from kivy.uix.anchorlayout import AnchorLayout
from kivy.uix.gridlayout import GridLayout
from kivy.uix.label import Label
from kivy.uix.video import Video
from kivy.uix.relativelayout import RelativeLayout
from kivy.graphics import *
from kivy.lang import Builder
from kivy.uix.boxlayout import BoxLayout
from random import random
from kivy.properties import ListProperty


kv = '''
<ColoredLabel>:
    size: (100,100)
    pos: (10,10) # no effect
    background_color:
    canvas.before:
        Color:
            rgba: self.background_color
        Rectangle:
            pos: self.pos
            size: self.size
    '''

Builder.load_string(kv)

class ColoredLabel(Label):
    background_color = ListProperty((0,0,0,1))

class MyApp(App):
    def build(self):
        f = AnchorLayout()
        g = GridLayout(cols=2, rows=2)
        layout = BoxLayout(size_hint=(1, None), height=50)
#        v = Video(source='driver.mp4', state='play', options={'eos':'loop'})
        l1 = Label(text="jenkins", font_size=32)
        l2 = Label(text="git", font_size=32)
#        f.add_widget(v)

        label = ColoredLabel(text="Hello World!", size_hint=(None, None), background_color=(random(), random(), random(), 1))
        g.add_widget(label)

        f.add_widget(g)

        return f

if __name__ == "__main__":
    MyApp().run()

注意 ColoredLabel 的 Rectange 需要有 pos: self.pos 和 size: self.size在标签实际所在的位置绘制。这就是为什么我在上面的级别中更改了 Label 本身的大小。 Canvas 大小与其绑定(bind)。至于位置，它由放置 ColoredLabel 的 Layout 控制，因此从 ColoredLabel 类更改它不会有太大变化。与 FloatLayout 比较:

import kivy
from kivy.app import App
from kivy.uix.anchorlayout import AnchorLayout
from kivy.uix.gridlayout import GridLayout
from kivy.uix.label import Label
from kivy.uix.video import Video
from kivy.uix.relativelayout import RelativeLayout
from kivy.graphics import *
from kivy.lang import Builder
from kivy.uix.boxlayout import BoxLayout
from random import random
from kivy.properties import ListProperty

from kivy.uix.floatlayout import FloatLayout


kv = '''
<ColoredLabel>:
    size: (150, 200)
    pos: (50, 150)
    background_color:
    canvas.before:
        Color:
            rgba: self.background_color
        Rectangle:
            pos: self.pos
            size: self.size
    '''

Builder.load_string(kv)

class ColoredLabel(Label):
    background_color = ListProperty((0,0,0,1))

class MyApp(App):
    def build(self):
        f = FloatLayout()
        label = ColoredLabel(text="Hello World!", size_hint=(None, None), background_color=(random(), random(), random(), 1))
        f.add_widget(label)

        return f

if __name__ == "__main__":
    MyApp().run()

在这种情况下，更改 ColoredLabel 中的 pos 实际上会产生影响。