如何解决“无效的属性名称”错误，使文件选择器具有奇异效果？

Question

我是kivy的新手，正在尝试构建一个应用程序，其中有三个选项卡：一个用于加载图像，另一个用于并排显示图像和灰度版本，最后一个选项卡仅用于显示图像。灰度图像。

我从this link获得了以下内容，希望将其用于python 3，但是我一再收到以下错误。

  

无效的属性名称

这是我当前正在使用的代码：

import kivy; 
from kivy.app import App
from kivy.uix.tabbedpanel import TabbedPanel
from kivy.properties import ObjectProperty
from kivy.lang import Builder
from PIL import*

Builder.load_string("""
<RootWidget>:
 manager:manager
 img:img
 img3:img3
 img4:img4
 lab:lab
 do_default_tab:False
 ScreenManager:
    id:manager
    Screen:
        id:sc1
        name:'Load img'
        FileChooserIconView
            canvas.before:
                Color:
                    rgb:0.5, 0.4, 0.5
                Rectangle:
                    pos:self.pos
                    size: self.size
            on_selection:root.select_to(*args)
    Screen:
        id:sc2
        name:'Image'
        FloatLayout:
            Button:
                id:lab
                pos_hint:{"right": 0.55, 'top': 1}
                size_hint:.15,0.1

        RelativeLayout:
            Image:
                id:img
                on_touch_down:str('Relative:{}'.format(args[1].pos))
                post_hint:{"left": 1, 'bottom': 1}
                size_hint:0.5, 1
                allow_strech:True
        RelativeLayout:
            Image:
                id:img3
                post_hint:{"right": 1, 'bottom': 1}
                size_hint:0.5, 1
                allow_strech = True
        Screen:
            id:sc3
            name:'Image_'
            FloatLayout:
                Image:
                    id:img4
                    keep_data:True
                    post:self.pos
                    size: self.size
    TabbedPanelHeader:
        text.sc1.name
        background_color: 1,0,0,1
        screen:sc1.name
    TabbedPanelHeader:
        text:sc2.name
        background_color: 1,1,0,1
        screen:sc2.name
    TabbedPanelHeader:
        text:sc3.name
        background_color: 1,0,1,1
        screen:sc3.name
""")

class RootWidget(TabbedPanel):

 manager = ObjectProperty(None)

 def on_touch_up(self, touch):
    if not self.img3.collide_point(*touch.pos):
        return True
    else:
        self.lab.text ='Pos: (%d,%d)' %(touch.x, touch.y)
        return True

 def switch_to(self, header):    
    # set the Screen manager to load  the appropriate screen
    # linked to the tab head instead of loading content
    self.manager.current = header.screen
    # we have to replace the functionality of the original switch_to
    self.current_tab.state = "normal"
    header.state = 'down'
    self._current_tab = header
 def select_to(self, *args):
    try:
        print(args[1][0])
        iw = Image.open(args[1][0])
        iw.save('./phase.jpg')
        gray = iw.convert('1')
        gray.save('.gray_im.jpg')
        self.img3.source = './gray_im.jpg'
        self.img4.source = './gray_im.jpg'
        self.img.source = './phase.jpg'
        self.img.reload()
        self.img3.reload()
        self.img4.reload()
    except:
        pass

 def update_touch_lavel(self, label, touch):
    label.text = 'Pos:(%d, %d)' % (touch.x, touch.y)
    label.texture_update()
    label.pos = touch.pos
    label.size = label.texture_size[0] + 20, label.texture_size[1] + 20

class MainApp(App):
 title = 'Screen Widget'
 def build(self):
    return RootWidget()
 def on_pause(self):
    return True

if __name__ == '__main___':
  MainApp().run()

我不确定为什么会收到此错误。我非常感谢您提供一些帮助，以使代码按预期工作。

Answer 1

有关详细信息，请参阅示例。

示例

main.py

from kivy.app import App
from kivy.uix.tabbedpanel import TabbedPanel
from kivy.properties import ObjectProperty
from PIL import Image


class RootWidget(TabbedPanel):
    manager = ObjectProperty(None)
    img = ObjectProperty(None)
    img3 = ObjectProperty(None)
    img4 = ObjectProperty(None)
    lab = ObjectProperty(None)

    def on_touch_up(self, touch):
        if not self.img3.collide_point(*touch.pos):
            return True
        else:
            self.lab.text = 'Pos: (%d,%d)' % (touch.x, touch.y)
            return True

    def switch_to(self, header):
        # set the Screen manager to load  the appropriate screen
        # linked to the tab head instead of loading content
        self.manager.current = header.screen

        # we have to replace the functionality of the original switch_to
        self.current_tab.state = "normal"
        header.state = 'down'
        self._current_tab = header

    def select_to(self, *args):
        try:
            print(args[1][0])
            iw = Image.open(args[1][0])
            iw.save('./phase.jpg')
            gray = iw.convert('1')
            gray.save('./gray_im.jpg')
            self.img3.source = './gray_im.jpg'
            self.img4.source = './gray_im.jpg'
            self.img.source = './phase.jpg'
            self.img.reload()
            self.img3.reload()
            self.img4.reload()
        except:
            pass

    def update_touch_label(self, label, touch):
        label.text = 'Pos:(%d, %d)' % (touch.x, touch.y)
        label.texture_update()
        label.pos = touch.pos
        label.size = label.texture_size[0] + 20, label.texture_size[1] + 20


class TestApp(App):
    title = 'Screen Widget'

    def build(self):
        return RootWidget()

    def on_pause(self):
        return True


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

test.kv

#:kivy 1.10.1

<RootWidget>:
    manager: manager
    img: img
    img3: img3
    img4: img4
    lab: lab
    do_default_tab: False

    ScreenManager:
        id: manager

        Screen:
            id: sc1
            name:'Load img'

            FileChooserIconView:
                canvas.before:
                    Color:
                        rgb: 0.5, 0.4, 0.5
                    Rectangle:
                        pos: self.pos
                        size: self.size
                on_selection:
                    root.select_to(*args)

        Screen:
            id: sc2
            name: 'Image'

            FloatLayout:
                Button:
                    id: lab
                    pos_hint: {"right": 0.55, 'top': 1}
                    size_hint: .15,0.1

            RelativeLayout:
                Image:
                    id: img
                    on_touch_down:
                        str('Relative:{}'.format(args[1].pos))
                    pos_hint: {"left": 1, 'bottom': 1}
                    size_hint: 0.5, 1
                    allow_stretch: True

            RelativeLayout:
                Image:
                    id: img3
                    pos_hint: {"right": 1, 'bottom': 1}
                    size_hint: 0.5, 1
                    allow_stretch: True

        Screen:
            id: sc3
            name: 'Image_'

            FloatLayout:
                Image:
                    id: img4
                    keep_data: True
                    post: self.pos
                    size: self.size

    TabbedPanelHeader:
        text: sc1.name
        background_color: 1, 0, 0, 1
        screen: sc1.name

    TabbedPanelHeader:
        text: sc2.name
        background_color: 1, 1, 0, 1
        screen: sc2.name

    TabbedPanelHeader:
        text: sc3.name
        background_color: 1, 0, 1, 1
        screen: sc3.name

输出