android - Kivy 相机显示旋转 -90 度

Question

我正在使用带有 kivy 框架的 python 在 android 4.4 中访问我的相机。

这是我的简单代码:

from kivy.app import App
from kivy.uix.camera import Camera
from kivy.core.window import Window

class CamApp(App):
    def build(self):
        return Camera(resolution= Window.size)

CamApp().run()

但是当我运行我的代码时，它显示了这个:

理想情况下，它应该是这样的:

看起来 kivy 相机正在显示内置 -90 度的输出。这是正常现象还是错误？还是我应该自己旋转显示器？

Answer 1

Cristian 的解决方案对我不起作用。它会在写 canvas.before 的那一行抛出 Parser Exception:

kivy.lang.parser.ParserException: Parser: File "<inline>", line 21:
I python  :  ...
I python  :       19:        height: '48dp'
I python  :       20:        on_press: root.capture()
I python  :  >>   21:    canvas.before:
I python  :       22:        PushMatrix
I python  :       23:        Rotate:
I python  :  ...
I python  :  Invalid class name

关于 canvas.before 和 canvas.after 只能在其他对象中调用，以下代码对我有用:

from kivy.app import App
from kivy.lang import Builder
from kivy.uix.boxlayout import BoxLayout
import time
Builder.load_string('''
<CameraClick>:
    orientation: 'vertical'
    Camera:
        id: camera
        resolution: (640, 480)
        play: False
        canvas.before:
            PushMatrix
            Rotate:
                angle: -90
                origin: self.center
        canvas.after:
            PopMatrix
    ToggleButton:
        text: 'Play'
        on_press: camera.play = not camera.play
        size_hint_y: None
        height: '48dp'
    Button:
        text: 'Capture'
        size_hint_y: None
        height: '48dp'
        on_press: root.capture()
''')


class CameraClick(BoxLayout):
    def capture(self):
        '''
        Function to capture the images and give them the names
        according to their captured time and date.
        '''
        camera = self.ids['camera']
        timestr = time.strftime("%Y%m%d_%H%M%S")
        camera.export_to_png("IMG_{}.png".format(timestr))
        print("Captured")


class TestCamera(App):

    def build(self):
        return CameraClick()


TestCamera().run()

资源:

• https://kivy.org/doc/stable/examples/gen__canvas__rotation__py.html
• https://github.com/kivy-garden/garden.zbarcam/blob/20171220/zbarcam/zbarcam.kv#L22