Kivi - 如何根据取自 mysql 的变量更改标签文本

Question

我需要根据 MySql db 中一行的值更改标签。我有这张桌子：

 |id_match |        match        |
 | 1       |   Juventus - Milan  |
 | 2       |   Roma - inter      |

我有这个 .py

import mysql.connector
from kivmob import KivMob, TestIds,  RewardedListenerInterface
from kivy.app import App
from kivy.uix.button import Button
from kivymd.uix.boxlayout import MDBoxLayout
from kivymd.app import MDApp
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.lang import Builder
from kivy.properties import ObjectProperty
from kivy.core.window import Window
from kivy.properties import StringProperty

Builder.load_file("prove.kv")

db = mysql.connector.connect(
    db="db",
    host="127.0.0.1",
    user="root",
    password="-----")
c = db.cursor()

c.execute("""CREATE TABLE if not exists partite(
id_match INTEGER,
match VARCHAR(255),
PRIMARY KEY (id_match))
""")

class prono1(Screen):
    home = ObjectProperty(None)
    away = ObjectProperty(None)

    def get_match(self, id_partita):
        query = "SELECT partita FROM db.partite where id_partita = VALUES (%s)"
        values = (id_partita)
        c.execute(query, values)
        partita = c.fetchone() ## <---- In this variable I have the label that I want to display
        return print(partita)

class prono2(Screen):
    home = ObjectProperty(None)
    away = ObjectProperty(None)

    def addresultToDB(self):
        query = """INSERT INTO risultati (user_id, id_partita, home, away) VALUES (%s, %s, %s, %s) 
                    ON DUPLICATE KEY UPDATE
                    home = VALUES (home),
                    away = VALUES (away)"""
        values = (user_id, 2, self.home.text, self.away.text)
        c.execute(query, values)
        db.commit()
        print(c.rowcount, "record inserted.")

class ScreenManagement(ScreenManager):
    ID_global = StringProperty('cccc')


class MyApp(MDApp):
    user_id = StringProperty()

    def set_screen(self, screen_name):
        self.root.current = screen_name

    def build(self):
        sm = ScreenManager()
        sm.add_widget(prono1(name='prono1'))
        sm.add_widget(prono2(name='prono2'))
        return sm

if __name__ == "__main__":
    MyApp().run()

还有这个.KV

<Prono1>:
    name:'prono1'
    home: home
    away: away
    MDCard:
        size_hint: None, None
        size: 300,200
        pos_hint: {"center_x": 0.5, "center_y": 0.5}
        elevation: 10
        padding: 25
        spacing: 25
        orientation: "vertical"
        MDLabel:
            size_hint_y: None
            size_hint_x: 1
            height: self.texture_size[1]
            text_size: self.width, None
            font_size: 20
            padding: 10, 20
            color: 0,0,0,1
            text: 'bla bla bla' #### <------------ name of the match that I want to display (WITH ID = 1 - so Juventus - Milan)
            halign: 'center'
        GridLayout:
            cols:3
            MDTextFieldRect:
                id: home
                halign:"center"
                font_size:30
            MDLabel:
                id: None
                text:" - "
                font_size:18
                halign:"center"
            MDTextFieldRect:
                id: away
                font_size:30
                halign:"center"
    MDRoundFlatButton:
        text: "Invia"
        font_size: 12
        pos_hint: {"center_x": 0.75,"center_y": 0.20 }
        on_press: root.addresultToDB()


<Prono2>:
    name:'prono2'
    home: home
    away: away
    MDCard:
        size_hint: None, None
        size: 300,200
        pos_hint: {"center_x": 0.5, "center_y": 0.5}
        elevation: 10
        padding: 25
        spacing: 25
        orientation: "vertical"
        MDLabel:
            size_hint_y: None
            size_hint_x: 1
            height: self.texture_size[1]
            text_size: self.width, None
            font_size: 20
            padding: 10, 20
            color: 0,0,0,1
            text: 'bla bla bla' #### <------------ name of the match that I want to display (WITH ID = 2 - so Roma - inter)
            halign: 'center'
        GridLayout:
            cols:3
            MDTextFieldRect:
                id: home
                halign:"center"
                font_size:30
            MDLabel:
                id: None
                text:" - "
                font_size:18
                halign:"center"
            MDTextFieldRect:
                id: away
                font_size:30
                halign:"center"
    MDRoundFlatButton:
        text: "Invia"
        font_size: 12
        pos_hint: {"center_x": 0.75,"center_y": 0.20 }
        on_press: root.addresultToDB()

使用def get_match()，我正在获取我正在寻找的值。但我不知道如何在评论中突出显示的标签中显示。 这样，如果我更改每个 id_match 的匹配项，我在显示的标签中就有更新的匹配项。

Answer 1

尝试以下方法：

def build(self):
        self.sm = sm = ScreenManager()
        self.wid1 = wid1 = prono1(name='prono1')
        self.wid2 = wid2 = prono2(name='prono2')
        sm.add_widget(wid1)
        sm.add_widget(wid2)
        sm.ids['wid1']= wid1
        sm.ids['wid2']= wid2
        return sm

这样您就可以从.py 文件中的任何位置访问prono1 和prono2 instances。

现在，在.kv 文件中，在您要访问的标签中设置id。例如：

        MDLabel:
            id: labl1   ## <------ Here you set the id
            size_hint_y: None
            size_hint_x: 1
            height: self.texture_size[1]
            text_size: self.width, None
            font_size: 20
            padding: 10, 20
            color: 0,0,0,1
            text: 'bla bla bla' #### <------------ name of the match that I want to display (WITH ID = 2 - so Roma - inter)
            halign: 'center'

要从 .py 文件中访问该标签，您必须这样做：

App.get_running_app().sm.ids['wid1'].ids.labll

在上面的代码中，ids['wid1'] 是您的 prono1 实例，.ids.lbll 引用带有 id:labl1 的标签

现在您可以在程序中的任何位置编辑该标签，例如，如果您想在函数 get_match 中编辑该标签，则：

def get_match(self, id_partita):
        query = "SELECT partita FROM db.partite where id_partita = VALUES (%s)"
        values = (id_partita)
        c.execute(query, values)
        partita = c.fetchone() ## <---- In this variable I have the label that I want to display
        App.get_running_app().sm.ids['wid1'].ids.labll.text = 'Text has changed'
        return print(partita)