Question

我只想在Textinput中接受两个数字。我知道如何只接受数字，我知道如何只接受两个字母，但不怎么都接受。

此代码仅接受字母：

TextInput:
    multiline: False
    input_filter: lambda text, from_undo: text[:2 - len(self.text)]

此代码仅接受数字：

TextInput:
    multiline: False
    input_filter: "int"

但是当我尝试类似的操作时：

TextInput:
    multiline: False
    input_filter: "int", lambda text, from_undo: text[:2 - 
    len(self.text)]

我收到此错误：

TypeError: 'tuple' object is not callable

Answer 1

据我所知，您无法以这种方式做自己想做的事。但是您可以使用 NumericInput ，此类将使用 TextInput 并处理您的限制。希望对您有所帮助，与您的最初想法有些不同，但是可以解决问题。

所以请尝试遵循：

main.py文件

from kivy.app import App
from kivy.base import Builder
from kivy.properties import NumericProperty
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.textinput import TextInput
from kivy.uix.screenmanager import ScreenManager


class NumericInput(TextInput):
    min_value = NumericProperty(None)
    max_value = NumericProperty(None)

    def __init__(self, *args, **kwargs):
        TextInput.__init__(self, *args, **kwargs)
        self.input_filter = 'int' # The type of your filter
        self.multiline = False

    def insert_text(self, string, from_undo=False):
        new_text = self.text + string

        if new_text != "" and len(new_text) < 3:
            try:
                # Will try convert the text to a int and compare, if it's not a number
                # It will throw a exception and will not append the text into the input

                # If the value is between the values and is a int
                if self.min_value <= int(new_text) <= self.max_value:
                    TextInput.insert_text(self, string, from_undo=from_undo)
            except ValueError as e: # Just cannot convert to a `int`
                pass



class BoundedLayout(BoxLayout):
    pass


presentation = Builder.load_file("gui.kv")
class App(App):
    def build(self):
        return BoundedLayout()

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

gui.kv文件

#:kivy 1.0

<BoundedLayout>:
  orientation: 'horizontal'
  Label:
    text: 'Value'
  NumericInput:
    min_value : 0 # your smaller value, can be negative too
    max_value : 99 # Here goes the max value
    hint_text : 'Enter values between {} and {}'.format(self.min_value, self.max_value)

如何只在Texinputfield中接受两个数字？

1 个答案:

main.py文件

gui.kv文件