当我在 Kivy 中更改 window 大小时，如何更改小部件的大小？

Question

我是一名尝试做计算器的 python 初学者。 我需要帮助解决一个问题。 当我运行应用程序并通过拖动鼠标调整 window 的大小时，小部件不会调整为 window 的大小，并且位于 window 的末尾。 我试图返回 FloatLayout 而不是 class KalkulackaLayout 并且它以我想要的方式工作。 但是当我退回 class KalkulackaLayout 时，它不起作用，我需要退回这个 class。

Python 文件：

from kivy.app import App
from kivy.uix.label import Label
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.textinput import TextInput
from kivy.uix.button import Button
from kivy.uix.widget import Widget

class KalkulackaLayout(Widget):
    def button_cislo(self, cislo):
        pred = self.ids.kalkulacka_input.text

        if pred == "0":
            self.ids.kalkulacka_input.text = ""
            self.ids.kalkulacka_input.text = f"{cislo}"

        else:
            self.ids.kalkulacka_input.text = f"{pred}{cislo}"

    def znamenko(self, znamenko):
        pred = self.ids.kalkulacka_input.text
        self.ids.kalkulacka_input.text = f"{pred}{znamenko}"

    def vymazat(self):
        self.ids.kalkulacka_input.text = ""

    def vypocitej(self):
        pred = self.ids.kalkulacka_input.text
        try:
            vysledek = eval(pred)
            self.ids.kalkulacka_input.text = str(vysledek)
        except:
            self.ids.kalkulacka_input.text = "ERROR!"

    pass

class Kalkulacka(App):
    def build(self):
        return KalkulackaLayout()

if __name__=="__main__":
    Kalkulacka().run()

.kv 文件：

<KalkulackaLayout>
    FloatLayout:
        size:300,300
        Button:
            text: "1"
            size_hint:0.5,0.5
            pos_hint: {"bottom":0.1}
            on_press: root.button_cislo(1)

        Button:
            text: "2"
            size_hint:0.5,0.5
            pos_hint:{"right": 1, "bottom": 0.1}
            on_press: root.button_cislo(2)

        Button:
            text: "3"
            size_hint:0.5,0.5
            pos_hint:{"right": 1.5, "bottom": 0.1}
            on_press: root.button_cislo(3)

        Button:
            text: "÷"
            size_hint:0.5,0.5
            pos_hint:{"right": 2, "bottom": 0.1}
            on_press: root.znamenko("/")

        Button:
            text: "-"
            size_hint:0.5,0.5
            pos_hint:{"right": 2.5, "bottom": 0.1}
            on_press: root.znamenko("-")

        Button:
            text: "4"
            size_hint:0.5,0.5
            pos_hint:{"top": 1}
            on_press: root.button_cislo(4)

        Button:
            text: "5"
            size_hint:0.5,0.5
            pos_hint:{"right": 1, "top": 1}
            on_press: root.button_cislo(5)

        Button:
            text: "6"
            size_hint:0.5,0.5
            pos_hint:{"right": 1.5, "top": 1}
            on_press: root.button_cislo(6)

        Button:
            text: "x"
            size_hint:0.5,0.5
            pos_hint:{"right": 2, "top": 1}
            on_press: root.znamenko("*")

        Button:
            text: "+"
            size_hint:0.5,0.5
            pos_hint:{"right": 2.5, "top": 1}
            on_press: root.znamenko("+")

        Button:
            text: "7"
            size_hint:0.5,0.5
            pos_hint:{"top": 1.5}
            on_press: root.button_cislo(7)

        Button:
            text: "8"
            size_hint:0.5,0.5
            pos_hint:{"right": 1, "top": 1.5}
            on_press: root.button_cislo(8)

        Button:
            text: "9"
            size_hint:0.5,0.5
            pos_hint:{"right": 1.5, "top": 1.5}
            on_press: root.button_cislo(9)

        Button:
            text: "="
            size_hint:0.5,0.5
            pos_hint:{"right": 2, "top": 1.5}
            on_press: root.vypocitej()

        Button:
            text: "C"
            size_hint:0.5,0.5
            pos_hint:{"right": 2.5, "top": 1.5}
            on_press: root.vymazat()

        TextInput:
            text: ""
            size_hint: 2.667,0.25
            font_size: 60
            pos_hint: {"top":2, "right":2.667}
            id: kalkulacka_input

Answer 1

class KalkulackaLayout(Widget):

不是从 Widget 继承，而是从布局 class 继承，例如BoxLayout ，当它自己的大小发生变化时，它会自动重新定位其子级。