Python 我只想在一个可滚动的文本框上显示函数的结果

当我点击Encrypt时，终端会显示一条加密消息。我只是想在一个可滚动的文本框上显示消息，并能够复制加密消息。我尝试了很多想法，但都做不到

CryptoMD2.py

from kivymd.app import MDApp
from kivy.lang import Builder
from kivy.uix.screenmanager import ScreenManager
from kivy.factory import Factory
from kivy.animation import Animation
import string
from kivy.properties import ObjectProperty
from kivy.core.window import Window
from kivymd.uix.label import Label
from kivy.uix.scrollview import ScrollView

Window.size = (360, 600)
alphabet = string.ascii_lowercase


class Encrypt:

    def encrypt(self, Text, key):
        Text = Text.lower()
        key = key
        Key = int(key)

        encrypted_message = ""

        for c in Text:
            if c in alphabet:
                position = alphabet.find(c)
                new_position = (position + Key) % 26
                new_character = alphabet[new_position]
                encrypted_message += new_character



            else:
                encrypted_message += c
        message = str(encrypted_message)
        print(message.upper())

    def decrypt(self, Text, key):
        Text = Text.lower()
        key = key
        Key = int(key)

        encrypted_message = ""

        for c in Text:
            if c in alphabet:
                position = alphabet.find(c)
                new_position = (position - Key) % 26
                new_character = alphabet[new_position]
                encrypted_message += new_character



            else:
                encrypted_message += c
        message = str(encrypted_message)
        print(message.upper())


class CryptoMD(MDApp):
    Encrypt = ObjectProperty()

    def __init__(self, **kwargs):
        self.Encrypt = Encrypt()
        self.title = 'Crypto'
        self.sm = ScreenManager()
        super().__init__(**kwargs)

    def animate_card(self, widget):
        anim = Animation(pos_hint={"center_y": 0.6}, duration=1)
        anim.start(widget)

    def animate_background(self, widget):
        anim = Animation(size_hint_y=1) + Animation(size_hint_y=0.5, duration=0.5)
        anim.start(widget.ids.bx)

    def build(self):
        self.sm.add_widget(Factory.Main())
        return self.sm


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

这是cryptomd.kv

#:kivy 1.11.1
#:import rgba kivy.utils.rgba


<Main@Screen>:
    name: "cryptomd"

    on_enter:
        app.animate_card(card)
        app.animate_background(background)

    BackgroundLayer:
        id: background

    MDCard:
        id:card
        orientation: 'vertical'
        size_hint: [0.8, 0.7]
        pos_hint: {'center_x': 0.5, 'center_y': 0}
        padding: [20, 10, 10, 20]
        spacing: 7

        BoxLayout:
            padding: [10, 10, 10, 10]
            orientation: 'vertical'

            MDLabel:
                text: "[color=000000] Caesar Cipher [/color]"
                text_size: self.size
                font_size: 30
                bold: True
                markup: True
                halign: "center"
                valign: "top"


        MDTextField:
            id: Text
            text: "A"
            auto_indent: True
            allow_copy: True
            multiline: False
            helper_text: "Enter Text..."
            helper_text_mode: "persistent"
            required: True



        MDTextField:
            id: key
            text: "1"
            input_filter: "int"
            helper_text: "Enter Key..."
            helper_text_mode: "persistent"
            required: True



        MDRoundFlatButton:
            id: encrypt
            text: "Encrypt"
            size_hint_x: 0.6
            pos_hint: {'center_x': 0.5}
            on_press:
                app.Encrypt.encrypt(Text.text, key.text) if Text.text != "" else None

        MDRoundFlatButton:
            id: decrypt
            text: "Decrypt"
            size_hint_x: 0.6
            pos_hint: {'center_x': 0.5}
            on_press:
                app.Encrypt.decrypt(Text.text, key.text) if Text.text != "" else None





<BackgroundLayer@BoxLayout>:
    orientation: 'vertical'
    BoxLayout:
        id: bx
        orientation: 'vertical'
        size_hint_y: 0.1
        canvas.before:
            Color:
                rgba: rgba('#8A2BE2')
            RoundedRectangle:
                pos: self.pos
                size: self.size
                radius: [0, 0, 40, 40]

    BoxLayout:
        orientation: 'horizontal'
        padding: [10, 10, 10, 30]