成功解决 python+kivy的raise Exception(‘SDL2: Unable to load image‘) Unable to get a Window, abort.

运行python+kivy一个小程序出错，代码如下：

from kivy.app import App
from kivy.uix.floatlayout import FloatLayout

class SizeFloat(FloatLayout):
    def __init__(self, **kwargs):
        super().__init__(**kwargs)

class SizeApp(App):
    def build(self):
        return SizeFloat()

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

试运行，出错如下：

[CRITICAL] [Window      ] Unable to find any valuable Window provider. Please enable debug logging (e.g. add -d if running from the command line, or change the log level in the config) and re-run your app to identify potential causes
sdl2 - Exception: SDL2: Unable to load image
  File "C:\PythonProject\kv-demo-env\lib\site-packages\kivy\core\__init__.py", line 71, in core_select_lib
    cls = cls()
  File "C:\PythonProject\kv-demo-env\lib\site-packages\kivy\core\window\window_sdl2.py", line 152, in __init__
    super(WindowSDL, self).__init__()
  F