如何使用复选框实现 kivy ScrollView？

Posted 2023-04-14

【中文标题】如何使用复选框实现 kivy ScrollView？

【英文标题】：how to implement kivy ScrollView with checkboxes?

【发布时间】：2021-10-06 06:42:09

【问题描述】：

我对编程完全陌生，很抱歉我的菜鸟问题。请告诉我如何在我的应用程序中实现 ScrollView？我不明白在这种情况下是否需要实现 runTouchApp？如果有，必须放在哪里？

我查看了其他滚动视图问题，但没有找到适合我的答案。我将不胜感激有关如何实现内部滚动的任何提示。

提前谢谢你。

'''

ScrollView:
    do_scroll_x: False
    do_scroll_y: True

    Label:
        size_hint_y: None
        height: self.texture_size[1]
        text_size: self.width
        padding: 10, 10
        text:
            'really some amazing text\n' * 100
'''


from kivy.app import runTouchApp
from kivy.app import App
from kivy.uix.button import Button
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.uix.gridlayout import GridLayout
from kivy.core.window import Window
from kivy.uix.label import Label
from kivy.uix.checkbox import CheckBox
from kivy.properties import StringProperty
from kivy.uix.scrollview import ScrollView

Window.size = (240, 480)
Window.clearcolor = (180 / 255, 90 / 255, 3 / 255, 1)
Window.title = "Test"

count = None


class MenuScreen(Screen):
    def __init__(self, **kw):
        super(MenuScreen, self).__init__(**kw)
        box = BoxLayout(orientation='vertical')
        box.add_widget(Button(text='item list', background_color=(0, 1, 1, 1), on_press=lambda x:
        sm.switch_to(Setup(name='setup'))))
        self.add_widget(box)


class Setup(Screen):
    def __init__(self, **kw):
        super(Setup, self).__init__(**kw)

        my_list = ['red', 'green', 'yellow', 'blue', 'white', 'magenta', 'violet']

        self.scroll_list(my_list)

    def scroll_list(self, x):

        grid = GridLayout(cols=1, padding=10, spacing=3)

        label_question = Label(text=f'select\nfrom list:', size_hint=(1, None), halign="left", valign="middle")
        label_question.bind(size=label_question.setter('text_size'))
        grid.add_widget(label_question)

        grid_scroll = GridLayout(cols=2)


        for i in x:
            lbl = Label(text=f'i', size_hint=(1, None), halign="left", valign='middle')
            lbl.bind(size=lbl.setter('text_size'))

            grid_scroll.add_widget(lbl)
            radio_btn = CustomCheckBox(text=str(i), size_hint=(0.2, None), group=1)

            grid_scroll.add_widget(radio_btn)
        grid_scroll.bind(minimum_height=grid_scroll.setter('height'))
        root = ScrollView(size_hint=(1, 0.7))

        root.add_widget(grid_scroll)

        grid.add_widget(root)

        grid.add_widget(
            Button(text='submit', background_color=(0, 1, 1, 1), pos_hint=(None, 1), size_hint_y=None,
                   height=60,
                   on_press=lambda x: sm.switch_to(MenuScreen(name='menu'))))

        self.add_widget(grid)



class CustomCheckBox(CheckBox):
    text = StringProperty('')

    def on_active(self, instance, value):
        global count
        if value:
            count = instance.text
            print(f'\tThe checkbox text=instance.text is active')


sm = ScreenManager()
sm.add_widget(MenuScreen(name='menu'))


class Test(App):
    def __init__(self, **kvargs):
        super(Test, self).__init__(**kvargs)

    def build(self):
        return sm


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

【参考方案1】：

我认为您需要做的就是修改该行：

grid_scroll = GridLayout(cols=2)

到：

grid_scroll = GridLayout(cols=2, size_hint_y=None)

ScrollView 的子级必须至少将size_hints 之一设置为None。

【讨论】：

非常感谢！！！有用！！！我以为我已经在kv部分指出了这一点，甚至没有怀疑我必须在那里写！你很棒！谢谢，谢谢，谢谢！