在 KivyMD Python 的 JSON 文件中存储数据时出错

Question

我试图将从用户那里获取的用户名存储在 .json 文件中。但它不能正常工作。用户重复输入用户名后，随机存储在一个json文件中。请用这段代码解决问题。

有时 .json 文件是随机创建的。但不是第一次。

.kv 文件

screen_helper = """
ScreenManager:
    SetUpWindow:
    Home:

<SetUpWindow>:
    name: 'settingup'
    MDTextField:
        id:username_text_fied
        pos_hint: {'center_x':0.5,'center_y':0.45}
        size_hint: (0.7,0.1)
        hint_text : 'Name your Studio'
        helper_text: 'Required'
        helper_text_mode: 'on_focus'
        icon_right: 'account'
        icon_right_color: app.theme_cls.primary_light
        required : True
    MDRaisedButton:
        id:disabled_button
        disabled: True
        text:"Next"
        md_bg_color:app.theme_cls.primary_color
        pos_hint: {'center_x':0.9,'center_y':0.08}
        font_style: 'Button'
        ripple_rad_default : 40
        ripple_duration_out : 1
        md_bg_color: app.theme_cls.primary_dark
        on_press:
            root.manager.current = 'home'
            root.manager.transition.direction = 'left'   

<Home>:
    name: 'home'
"""

.py 文件

from kivy.lang.builder import Builder
from kivy.uix.screenmanager import Screen, ScreenManager
from kivymd.app import MDApp
from kivy.storage.jsonstore import JsonStore

class SetUpWindow(Screen):
    pass

sm = ScreenManager()
sm.add_widget(SetUpWindow(name='settingup'))

class Mode(MDApp):
    def build(self):
        screen = Screen()
        self.screen = Builder.load_string(screen_helper)
        screen.add_widget(self.screen)
        self.username_text = self.screen.get_screen('settingup').ids.username_text_fied.text

        return screen


        self.store.put('UserInfo', name=self.username_text)
        self.username_changer()

    def username_changer(self):
        self.screen.get_screen('home').ids.bottomappbar.title = f"Studio {self.store.get('UserInfo')['name']}"


    def on_start(self):
        self.store = JsonStore("std_profile.json")
        try:
            if self.store.get('UserInfo')['name'] != "":
                self.username_changer()
                self.screen.get_screen('home').manager.current = 'home'

        except KeyError:
            self.screen.get_screen('settingup').manager.current = 'settingup'
            
Mode().run()

Answer 1

这是您的代码的修改版本，可以满足您的要求：

from kivy.lang.builder import Builder
from kivy.uix.screenmanager import Screen
from kivymd.app import MDApp
from kivy.storage.jsonstore import JsonStore

screen_helper = """
ScreenManager:
    SetUpWindow:
    Home:

<SetUpWindow>:
    name: 'settingup'
    MDTextField:
        id:username_text_fied
        pos_hint: {'center_x':0.5,'center_y':0.45}
        size_hint: (0.7,0.1)
        hint_text : 'Name your Studio'
        helper_text: 'Required'
        helper_text_mode: 'on_focus'
        icon_right: 'account'
        icon_right_color: app.theme_cls.primary_light
        required : True
        on_text:
            disabled_button.disabled = False  # enable next button
    MDRaisedButton:
        id:disabled_button
        disabled: True
        text:"Next"
        md_bg_color:app.theme_cls.primary_color
        pos_hint: {'center_x':0.9,'center_y':0.08}
        font_style: 'Button'
        ripple_rad_default : 40
        ripple_duration_out : 1
        md_bg_color: app.theme_cls.primary_dark
        on_press:
            app.save_user_name()  # save user name to Json
            root.manager.current = 'home'
            root.manager.transition.direction = 'left'   

<Home>:
    name: 'home'
    MDBottomAppBar:
        MDToolbar:
            id: bottomappbar
            title: "Title"
            icon: "git"
            type: "bottom"
            left_action_items: [["menu", lambda x: x]]
            mode: "free-end"
"""

class SetUpWindow(Screen):
    pass


class Home(Screen):
    pass


class Mode(MDApp):
    def build(self):
        return Builder.load_string(screen_helper)

    def save_user_name(self):  # added method to actually save user name to JSon
        self.username_text = self.root.get_screen('settingup').ids.username_text_fied.text
        self.store.put('UserInfo', name=self.username_text)
        self.username_changer()

    def username_changer(self):
        self.root.get_screen('home').ids.bottomappbar.title = f"Studio {self.store.get('UserInfo')['name']}"

    def on_start(self):
        self.store = JsonStore("std_profile.json")
        try:
            if self.store.get('UserInfo')['name'] != "":
                self.username_changer()
                self.root.get_screen('home').manager.current = 'home'

        except KeyError as e:
            self.root.get_screen('settingup').manager.current = 'settingup'


Mode().run()

请注意 build() 方法中的更改以及正在构建 ScreenManager 和 SetUpWindow 的其他代码的删除。对 self.screen 的引用已替换为 self.root。 Next 按钮现在保存用户名。

在 KivyMD Python 的 JSON 文件中存储数据时出错

Error while Storing data in a JSON file in KivyMD Python

python

database

json

kivy

kivymd

.kv 文件

.py 文件