Python/Kivy : Form submit using enter key

问题

I am moving from one TextInput to another TextInput using enter key.
I want to move from last TextInput to Button using enter key .When I press again enter key then should be call root.abc() function.
Can someone tell me how to done it?

test.py

from kivy.uix.screenmanager import Screen
from kivy.app import App
from kivy.core.window import Window

Window.clearcolor = (0.5, 0.5, 0.5, 1)
Window.size = (300, 100)

class User(Screen):

    def abc(self):
        print('Test')

class Test(App):

    def build(self):
        return self.root

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

test.kv

User:
    BoxLayout:
        orientation: "vertical"

        TextInput:
            id:test1
            focus : True
            text: ' '
            width: 100
            multiline: False
            on_text_validate: test2.focus = True

        TextInput:
            id:test2
            text: ' '
            width: 100
            multiline: False
            on_text_validate: test3.focus = True

        Button:
            id:test3
            text: 'Ok'
            on_press : root.abc()

回答1:

Here we are using a key down binding, check for button's focus and Enter key pressed.

Example

main.py

from kivy.uix.screenmanager import Screen
from kivy.app import App
from kivy.core.window import Window
from kivy.properties import ObjectProperty

Window.clearcolor = (0.5, 0.5, 0.5, 1)
Window.size = (300, 100)


class User(Screen):
    test3 = ObjectProperty(None)

    def __init__(self, **kwargs):
        super(User, self).__init__(**kwargs)
        Window.bind(on_key_down=self._on_keyboard_down)

    def _on_keyboard_down(self, instance, keyboard, keycode, text, modifiers):
        if self.test3.focus and keycode == 40:  # 40 - Enter key pressed
            self.abc()

    def abc(self):
        print('Test')


class Test(App):

    def build(self):
        return self.root


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

test.kv

#:kivy 1.10.0

User:
    test3: test3
    BoxLayout:
        orientation: "vertical"

        TextInput:
            id:test1
            focus : True
            text: ' '
            width: 100
            multiline: False
            on_text_validate: test2.focus = True

        TextInput:
            id:test2
            text: ' '
            width: 100
            multiline: False
            on_text_validate:
                test3.background_normal = ''
                test3.background_color = [0, 0, 1, 0.5]    # 50% translucent blue
                test3.focus = True

        Button:
            id:test3
            text: 'Ok'
            focus: False
            on_press : root.abc()

Output

来源：https://stackoverflow.com/questions/49727988/python-kivy-form-submit-using-enter-key