Question

我遵循了widget tutorial for Kivy，但是除非在按下清除按钮后重新调整窗口大小，否则我无法在绘画后清除画布（来自他们的“简单绘画应用”教程）。请帮忙。我正在使用kivy v1.10.1和python v3.7.0。在Windows 10 64位操作系统上。此外，在分散模式下的小部件在您拖动到新位置时会留下痕迹，在调整窗口大小时也会清除。参见下面的代码：

from random import random
from kivy.app import App
from kivy.uix.widget import Widget
from kivy.uix.button import Button
from kivy.graphics import Color, Ellipse, Line


class MyPaintWidget(Widget):
    def on_touch_down(self, touch):
        color = (random(), 1, 1)
        with self.canvas:
            Color(*color, mode='hsv')
            d = 30.
            Ellipse(pos=(touch.x - d / 2, touch.y - d / 2), size=(d, d))
            touch.ud['line'] = Line(points=(touch.x, touch.y))

    def on_touch_move(self, touch):
        touch.ud['line'].points += [touch.x, touch.y]


class MyPaintApp(App):
    def build(self):
        parent = Widget()
        self.painter = MyPaintWidget()
        clearbtn = Button(text='Clear')
        clearbtn.bind(on_release=self.clear_canvas)
        parent.add_widget(self.painter)
        parent.add_widget(clearbtn)
        return parent

    def clear_canvas(self, obj):
        self.painter.canvas.clear()


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

Kivy canvas.clear（）不清除画布

0 个答案: