Python / Kivy：从一个类调用函数到另一个类，并在Python中显示小部件

Question

我正在使用Python-2.7和Kivy。当我运行 test.py 时，会显示一个显示按钮。当我点击“显示”按钮时，会显示标签和值。我从数据库中获取它，但现在我将其定义为静态数组。

当我点击Item1标签然后调用def open_form并在使用id调用EditPopup(self)后传递id 11并显示带有值的弹出窗口。

之后我改变itemCode并点击“确定”按钮，然后更新数据库中的数据。

之后我调用Invoice().abc()然后它会在Pycharm控制台中打印更新的数据，但不会在layout.add_widget（弹出窗口）中显示最新的数据。

有人能告诉我我在哪里弄错了吗？

test.py

from kivy.uix.label import Label
from kivy.uix.screenmanager import Screen
from kivy.app import App
from kivy.core.window import Window
from functools import partial
from kivy.uix.popup import Popup
from kivy.properties import BooleanProperty, ListProperty, StringProperty, ObjectProperty, NumericProperty
import sqlite3 as lite
#con = lite.connect('test.db')

#con.text_factory = str
#cur = con.cursor()
Window.clearcolor = (0.5, 0.5, 0.5, 1)
Window.size = (600, 600)

class MyLabel(Label):
    pass


class EditPopup(Popup):
    mode = StringProperty("")
    label_rec_id = StringProperty("Id")
    col_data = ListProperty(["?", "?", "?"])
    index = NumericProperty(0)

    def __init__(self, obj, **kwargs):
        super(EditPopup, self).__init__(**kwargs)

        if obj.mode == "Update":
            #cur.execute("SELECT * FROM `item` WHERE itemId=?", (edit_id,))
            #row = cur.fetchone()
            row = (11, 'Item1', '1001')
            print(row[0])
            self.col_data[0] = str(row[0])
            self.col_data[1] = row[1]
            self.col_data[2] = row[2]

    def update(self,obj):
        #cur.execute("UPDATE `item` SET itemName=?, itemCode=? WHERE itemId=?",
                #('Item1', 9999, 11))
        #con.commit()
        Invoice().abc()

class Invoice(Screen):
    def __init__(self, **kwargs):
        super(Invoice, self).__init__(**kwargs)

    def abc(self):
        #fetching from database
        #cur.execute("SELECT * FROM `item` order by itemId asc")
        #rows = cur.fetchall()
        rows = [(11, 'Item1', '1001'), (12, 'Item2', '2001'), (13, 'Item3', '102')]
        print(rows)
        layout = self.ids['invoices']
        for row in rows:
            layout.add_widget(MyLabel(text=str('[ref=world]' + row[1]) + '[/ref]',
                                      size_hint_x=.35,
                                      halign='left',
                                      markup=True,
                                      on_ref_press=partial(self.open_form, row[0])))

    def open_form(self, id, *args):
        global edit_id
        edit_id = id
        self.mode = "Update"
        popup = EditPopup(self)
        popup.open()

class Test(App):

    def build(self):
        return Invoice()

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

test.kv

<Button@Button>:
    font_size: 15
    font_name: 'Verdana'
    size_hint_y:None
    height: 30

<MyLabel>:
    font_size: 15
    font_name: 'Verdana'
    size_hint_y:None
    height: 30
    text_size: self.size
    valign: 'middle'
    canvas.before:
        Color:
            rgb: .6, .6, .6
        Rectangle:
            pos: self.pos
            size: self.size

<EditPopup>:
    title: self.mode + " Item"
    size_hint: None, None
    title_size: 20
    title_font: "Verdana"
    size: 400, 275
    auto_dismiss: False

    BoxLayout:
        orientation: "vertical"
        GridLayout:
            cols: 2
            #backgroun_color: 0, 0.517, 0.705, 1
            spacing: 10, 10
            padding: 20, 20
            Label:
                text: root.label_rec_id
                text_size: self.size
            Label:
                id: itemId
                text: root.col_data[0]
                text_size: self.size
            Label:
                text: "Item Name"
                text_size: self.size
                valign: 'middle'
            TextInput:
                id: itemName
                text: root.col_data[1]
                text_size: self.size
            Label:
                text: "State Code"
                text_size: self.size
                valign: 'middle'
            TextInput:
                id: itemCode
                text: root.col_data[2]
                text_size: self.size

        GridLayout:
            cols: 2
            padding: 10, 0, 10, 10
            spacing: 10, 10
            row_default_height: '20dp'
            size_hint: .55, .3
            pos_hint: {'x': .25, 'y':.65}

            Button:
                size_hint_x: .5
                text: "Ok"
                on_release:
                    root.update(root)
                    root.dismiss()

            Button:
                size_hint_x: .5
                text: "Cancel"
                on_release: root.dismiss()



<Invoice>:
    BoxLayout:
        orientation: "vertical"
        padding : 15, 15

        BoxLayout:
            orientation: "vertical"
            padding : 5, 5
            size_hint: .6, None
            pos_hint: {'x': .18,}


            BoxLayout:
                orientation: "horizontal"
                padding : 5, 5
                spacing: 10, 10
                size: 800, 40
                size_hint: 1, None

                Button:
                    text: "Show"
                    size_hint_x: .05
                    spacing_x: 30
                    on_press:root.abc()

        BoxLayout:
            orientation: "horizontal"
            size_hint: 1, 1

            BoxLayout:
                orientation: "vertical"
                size_hint: .5, 1
                padding : 0, 15
                spacing: 10, 10
                size: 500, 30

                GridLayout:
                    id: invoices
                    cols: 2
                    #orientation: "horizontal"
                    padding : 5, 0
                    spacing: 10, 0
                    #size: 500, 30
                    size_hint: 1, 1
                    pos: self.pos
                    size: self.size

Answer 1

您正在创建新的Invoice实例，而不是使用现有实例。

 Invoice().abc()

尝试改为：

class EditPopup(Popup):
    mode = StringProperty("")
    label_rec_id = StringProperty("Id")
    col_data = ListProperty(["?", "?", "?"])
    index = NumericProperty(0)

    def __init__(self, obj, **kwargs):
        super(EditPopup, self).__init__(**kwargs)
        self.obj = obj # will need it later...

    def update(self,obj):
        #cur.execute("UPDATE `item` SET itemName=?, itemCode=? WHERE itemId=?",
                #('Item1', 9999, 11))
        #con.commit()

        self.obj.abc()  # was Invoice().abc()

Answer 2

问题

您正在通过在类EditPopup中的方法更新中调用 Invoice（）。abc（）来即时启动类Invoice的第二个实例。

解决方案

1）test.py

在EditPopup类的方法更新中注释Invoice（）。abc（）并添加传递。

def update(self, obj):
    #cur.execute("UPDATE `item` SET itemName=?, itemCode=? WHERE itemId=?",
            #('Item1', 9999, 11))
    #con.commit()
    # Invoice().abc()
    pass

2）test.kv

在调用方法更新后，在类EditPopup中添加对方法abc的调用。

    Button:
        size_hint_x: .5
        text: "Ok"
        on_release:
            root.update(root)
            app.root.abc()
            root.dismiss()

输出