Python：在表单中添加验证

Question

谁能告诉我如何在textInput上设置required验证
什么时候点击Ok按钮？
此时单击Ok 按钮，然后我会像这样检查每个TextInput。
if self.name.text.strip() == "":
但是如果我的表单有多个50 feilds，那么这将是非常冗长的代码？有人可以告诉我另一种在TextInput 上设置required 验证的简短方法。

test.py

from kivy.uix.screenmanager import Screen
from kivy.app import App
from kivy.lang import Builder
from kivy.core.window import Window
from kivy.properties import ObjectProperty
from kivy.uix.textinput import TextInput
Window.size = (500, 330)

class FloatInput(TextInput):

    def __init__(self, **kwargs):
        super(FloatInput, self).__init__(**kwargs)

    def on_text(self, instance, text):
        if text !="":
            print(text)

class TestScreen(Screen):
    name = ObjectProperty(None)
    clas = ObjectProperty(None)

    def check_validation(self):
        if self.name.text.strip() == "":
            print("Name is blank")
        elif self.clas.text.strip() == "":
            print("clas is blank")



class Test(App):
    def build(self):
        self.root = Builder.load_file('test.kv')
        return self.root


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

test.kv

#:kivy 1.10.0
TestScreen:
    name:name
    clas:clas

    GridLayout:
        cols: 2
        padding : 30,30
        spacing: 10, 10
        row_default_height: '40dp'

        Label:
            text: 'Name'

        FloatInput:
            id: name

        Label:
            text: 'Class'

        FloatInput:
            id: clas


        Button:
            text: 'Ok'
            on_release: root.check_validation()

        Button:
            text: 'Cancel'

Answer 1

1. 创建一个GridLayout的ScrollView
2. 使用循环创建由 Label 和 TextInput 小部件组成的表单的每一行
3. 使用循环访问 self.container.children 中的子小部件。

详情请参考以下示例。

示例

main.py

​​>

from kivy.app import App
from kivy.core.window import Window
from kivy.uix.screenmanager import Screen
from kivy.uix.label import Label
from kivy.uix.textinput import TextInput
from kivy.metrics import dp
from kivy.properties import ObjectProperty, DictProperty

Window.size = (500, 330)


class FloatInput(TextInput):

    def on_text(self, instance, text):
        if text != "":
            print("id={0}, text={1}".format(instance.id, text))


class TestScreen(Screen):
    container = ObjectProperty(None)

    def __init__(self, **kwargs):
        super(TestScreen, self).__init__(**kwargs)
        self.container.bind(minimum_height=self.container.setter('height'))
        self.create_form()

    def create_form(self):
        # create 50 labels and text inputs
        for i in range(50):
            label = Label(text="Label {}".format(i), size_hint_y=None, height=dp(40))
            text_input = FloatInput(id=str(i), hint_text="TextInput {}".format(i), size_hint_y=None, height=dp(40))
            self.container.add_widget(label)
            self.container.add_widget(text_input)

    def check_validation(self):
        for child in reversed(self.container.children):
            if isinstance(child, Label):
                label_text = child.text
            if isinstance(child, FloatInput):
                if child.text.strip() == "":
                    print("{0} - TextInput is blank, obj={1}".format(label_text, child))


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


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

test.kv

#:kivy 1.10.0

<TestScreen>:
    container: container

    BoxLayout:
        orientation: 'vertical'

        BoxLayout:
            orientation: 'vertical'

            ScrollView:

                GridLayout:
                    id: container
                    cols: 2
                    size_hint_y: None
                    padding : 30,30
                    spacing: 10, 10

        BoxLayout:
            size_hint_y: 0.2

            Button:
                text: 'Ok'
                on_release: root.check_validation()

            Button:
                text: 'Cancel'

输出