更改 Kivy 小部件的部分文本的颜色

Question

我正在尝试编写一个程序，如果我按下一个按钮，Label 小部件的部分文本的颜色就会改变。

例如，有一个带有文本“1/0”的标签小部件。现在，如果我按下按钮，1 的颜色会更改为某个指定的颜色。这是我试过的程序：

from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button
from kivy.lang import Builder
from kivy.utils import get_color_from_hex

Builder.load_string('''
#: import get_color_from_hex kivy.utils.get_color_from_hex
<b>:
    orientation: 'horizontal'
    Button:
        text: 'Press Me'
        on_press: num.text[0].color = get_color_from_hex('#04d3ff')

    Label:
        id: num
        text: '1/0'
''')

class b(BoxLayout):
    pass

class main(App):
    def build(self):
        return b()

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

这是我得到的错误：

Traceback (most recent call last):
   File "b.py", line 28, in <module>
     main().run()
   File "/usr/lib/python2.7/dist-packages/kivy/app.py", line 828, in run
     runTouchApp()
   File "/usr/lib/python2.7/dist-packages/kivy/base.py", line 487, in runTouchApp
     EventLoop.window.mainloop()
   File "/usr/lib/python2.7/dist-packages/kivy/core/window/window_sdl2.py", line 619, in mainloop
     self._mainloop()
   File "/usr/lib/python2.7/dist-packages/kivy/core/window/window_sdl2.py", line 362, in _mainloop
     EventLoop.idle()
   File "/usr/lib/python2.7/dist-packages/kivy/base.py", line 330, in idle
     self.dispatch_input()
   File "/usr/lib/python2.7/dist-packages/kivy/base.py", line 315, in dispatch_input
     post_dispatch_input(*pop(0))
   File "/usr/lib/python2.7/dist-packages/kivy/base.py", line 221, in post_dispatch_input
     listener.dispatch('on_motion', etype, me)
   File "kivy/_event.pyx", line 718, in kivy._event.EventDispatcher.dispatch (kivy/_event.c:7699)
   File "/usr/lib/python2.7/dist-packages/kivy/core/window/__init__.py", line 1030, in on_motion
     self.dispatch('on_touch_down', me)
   File "kivy/_event.pyx", line 718, in kivy._event.EventDispatcher.dispatch (kivy/_event.c:7699)
   File "/usr/lib/python2.7/dist-packages/kivy/core/window/__init__.py", line 1046, in on_touch_down
     if w.dispatch('on_touch_down', touch):
   File "kivy/_event.pyx", line 718, in kivy._event.EventDispatcher.dispatch (kivy/_event.c:7699)
   File "/usr/lib/python2.7/dist-packages/kivy/uix/widget.py", line 432, in on_touch_down
     if child.dispatch('on_touch_down', touch):
   File "kivy/_event.pyx", line 718, in kivy._event.EventDispatcher.dispatch (kivy/_event.c:7699)
   File "/usr/lib/python2.7/dist-packages/kivy/uix/behaviors/button.py", line 110, in on_touch_down
     self.dispatch('on_press')
   File "kivy/_event.pyx", line 714, in kivy._event.EventDispatcher.dispatch (kivy/_event.c:7654)
   File "kivy/_event.pyx", line 1224, in kivy._event.EventObservers.dispatch (kivy/_event.c:13497)
   File "kivy/_event.pyx", line 1108, in kivy._event.EventObservers._dispatch (kivy/_event.c:12329)
   File "/usr/lib/python2.7/dist-packages/kivy/lang.py", line 1557, in custom_callback
     exec(__kvlang__.co_value, idmap)
   File "<string>", line 7, in <module>
 AttributeError: 'str' object has no attribute 'color'

编辑：解决方案

此编辑适用于碰巧运行遇到类似情况并通过 Google 搜索到达此处的人。 Inclement 的解决方案非常有效。这是kv语言的解决代码：

<b>:
    orientation: 'horizontal'
    Button:
        text: 'Press Me'
        on_press: num.text = "[color=#04d3ff]1[/color]/0"
        on_release: num.text = "[color=#ffffff]1[/color]/0"

    Label:
        id: num
        markup: True
        text: '1/0'

Answer 1

使用 Kivy 的基本 markup syntax 设置颜色，以及标签中的 markup: True。

Answer 2

对于您在评论中提出的第二个问题"I ran into another problem now. :\ What if there is more than one Label? What if I want to change the first character of multiple Labels together?"您应该提出一个新问题并向我们提供一些代码。

但是，乍一看，您似乎可以简单地遍历标签并执行以下操作：

获取标签的当前文字(label.text)
通过对第一个字符使用标记来更新标签颜色。例如，如果 label.text = "my_text"，我可以通过更新标签内的以下内容来突出显示标签文本的 "m"：
```
text = '[color=FFFF00]'+label.text[0]+'[/color]'+label.text[1:]
```

此答案假设您有一组现有标签并且您想要修改每个标签的第一个字符。没有代码，很难给出更具体的答案，但这种通用方法可行。

更改 Kivy 小部件的部分文本的颜色

Changing color of a part of text of a Kivy widget

python

python-2.7

kivy

kivy-language