Python，Kivy。 如何禁用/启用按钮？

Question

当#1 (TextInput)或#2 (TextInput)或两者(TextInput)为空时是否可以禁用“结果”按钮并在两个TextInput都填充时启用按钮？ 我在.kv文件中找到并尝试了“ disabled: True ”，但后来我被卡住了，我不知道如何让它工作。

我创建了一个简单的代码来向您展示我想要实现的目标：

我的文件.py ：

import kivy
from kivy.app import App
from kivy.uix.label import Label
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.textinput import TextInput
from kivy.uix.button import Button
from kivy.properties import ObjectProperty


class test(BoxLayout):
    first = ObjectProperty()
    second = ObjectProperty()
    result = ObjectProperty()

    def result_final(self):
        x = int(self.first.text)
        y = int(self.second.text)

        z = x * y

        self.result.text = str(z)


class firstApp(App):
    def build(self):
        return test()


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

我的文件.kv ：

<test>:

    first: first_number
    second: second_number
    result: result_number

    orientation: "vertical"
    padding: 20
    spacing: 20

    BoxLayout:
        Label:
            text: "#1"
        TextInput:
            id: first_number
            input_filter: "int"

    BoxLayout:
        Label:
            text: "#2"
        TextInput:
            id: second_number
            input_filter: "int"

    BoxLayout:
        Button:
            text: 'RESULT'
            on_press: root.result_final()


    BoxLayout:
        TextInput:
            id: result_number**

Answer 1

是的，这很容易在您的kv中使用一些逻辑。 将此用于您的Result Button ：

    Button:
        text: 'RESULT'
        disabled: True if first_number.text == '' or second_number.text == '' else False
        on_press: root.result_final()

Answer 2

import kivy
from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.properties import ObjectProperty


class Test(BoxLayout):
    first = ObjectProperty()
    second = ObjectProperty()
    result = ObjectProperty()
    result_btn = ObjectProperty()
    empty = True

    def check(self):
        if self.first.text.strip() != '' and self.second.text.strip() != '':
            self.result_btn.disabled = False
        else:
            self.result_btn.disabled = True

    def result_final(self):
        x = int(self.first.text)
        y = int(self.second.text)

        z = x * y

        self.result.text = str(z)


class FirstApp(App):
    def build(self):
        return Test()


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

和.kv

<test>:

    first: first_number
    second: second_number
    result: result_number
    result_btn: result_btn
    orientation: "vertical"
    padding: 20
    spacing: 20

    BoxLayout:
        Label:
            text: "#1"
        TextInput:
            id: first_number
            input_filter: "int"
            on_text:
                root.check()

    BoxLayout:
        Label:
            text: "#2"
        TextInput:
            id: second_number
            input_filter: "int"
            on_text:
                root.check()

    BoxLayout:
        Button:
            id: result_btn
            text: 'RESULT'
            on_press: root.result_final()
            disabled: True if root.empty else False


    BoxLayout:
        TextInput:
            id: result_number

基本上，每次输入任何数字时，都会调用一个 check() 方法，该方法会检查两个输入是否为空。