Python中通过On_Press事件动态创建的Widget的引用ID

Question

问题：

如何通过 On_Press 事件引用 Python 中动态创建的小部件的 id？

目标：

当单击动态创建的按钮“测试 1”、“测试 2”或“测试 3”时，我希望打印该按钮的 ID。

更具体地说，我希望通过 def changer(self, *args) 方法打印该 ID

问题：

正如您通过查看提供的代码可能猜到的那样，我只能打印最后创建的按钮的 ID（“测试 3”）。

Python 代码：

from kivy.app import App
from kivy.lang import Builder
from kivy.uix.screenmanager import ScreenManager, Screen, FadeTransition
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button
from kivy.clock import Clock
from kivy.uix.widget import Widget
from functools import partial

class ScrollableLabelDataEntryInstructions(BoxLayout):
    pass

class NewGarageScreen(Screen):
    pass

class ContinueEditingScreen(Screen):
    pass

class GarageNameBoxLayout(BoxLayout):
    LatestID = "initial"
    def __init__(self, **kwargs):
        super(GarageNameBoxLayout, self).__init__(**kwargs)
        self.orientation = "vertical"
        Clock.schedule_interval(self.create_button, 5)

    def create_button(self, *args):
        self.box_share2.clear_widgets()
        app = App.get_running_app()
        sm = app.root

        #put GarageNameStartList data into app class, then pull from it in this class
        top_button_share = 1.1
        color = (.4, .4, .4, 1)
        for text in app.GarageNameStartList:
            top_button_share -= .4
            id_ = text
            self.LatestID = id_
            button_share = Button(background_normal='',
                                  background_color = color,
                                  id = id_,
                                  pos_hint = {"x": 0, "top": top_button_share},
                                  size_hint_y = None,
                                  height = 60,
                                  font_size = 30,
                                  text = text)
            button_share.bind(on_press = self.changer)
            button_share.bind(on_press = lambda *args: setattr(sm, 'current', "newgarage"))
            self.box_share2.add_widget(button_share)

    def changer(self,*args):
        print(self.LatestID)

class BackHomeWidget(Widget):
    pass

class MainScreen(Screen):
    pass

class AnotherScreen(Screen):
    pass

class ScreenManagement(ScreenManager):
    pass

presentation = Builder.load_file("example_on_press.kv")

class MainApp(App):
    GarageNameStartList = ["Test1", "Test2", "Test3"]

    def Update_GarageNameStartList(self, *args):
        self.GarageNameStartList = ["Test1", "Test2", "Test3"]   


    def build(self):
        return presentation

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

Kv 代码：

#: import FadeTransition kivy.uix.screenmanager.FadeTransition

ScreenManagement:
    transition: FadeTransition()
    MainScreen:
    AnotherScreen:
    NewGarageScreen:
    ContinueEditingScreen:

<SmallNavButton@Button>:    
    font_size: 32
    size: 125, 50    
    color: 0,1,0,1

<MedButton@Button>:
    font_size: 30
    size_hint: 0.25, 0.1
    color: 0,1,0,1

<BackHomeWidget>:
    SmallNavButton:
        on_release: app.root.current = "main"
        text: "Home"
        pos: root.x, root.top - self.height

<MainScreen>:
    name: "main"
    FloatLayout: 
        MedButton:
            on_release: app.root.current = "edit"
            text: "Edit"
            pos_hint: {"x":0.3728, "top": 0.4}

<AnotherScreen>:
    name: "edit"
    BackHomeWidget:
        SmallNavButton:
            on_release: app.root.current = "main"
            text: "Back"
            pos: root.x, root.top - (2.25*(self.height))
    FloatLayout:
        MedButton:
            on_release: app.root.current = "continueediting"
            text: "Continue Editing"
            pos_hint: {"x":0.25, "top": 0.6} 
        MedButton:
            on_release: app.root.current = "newgarage"
            text: "Create New"
            pos_hint: {"x":0.3728, "top": 0.4}

<NewGarageScreen>:
    name: "newgarage"
    BackHomeWidget:
        SmallNavButton:
            on_release: app.root.current = "edit"
            text: "Back"
            pos: root.x, root.top - (2.25*(self.height))
    FloatLayout:
        MedButton:
            text: "1. Groundfloor"
            pos_hint: {"x":0, "top": 0.6}


<GarageNameBoxLayout>:
    box_share2: box_share2
    ScrollView:
        GridLayout:
            id: box_share2
            cols: 1
            size_hint_y: None
            size_hint_x: 0.5
            spacing: 5
            padding: 130
            height: self.minimum_height
            canvas:
                Color: 
                    rgb: 0, 0, 0
                Rectangle:
                    pos: self.pos
                    size: self.size         

<ContinueEditingScreen>:
    name: "continueediting"
    GarageNameBoxLayout:
    BackHomeWidget:
        SmallNavButton:
            on_release: app.root.current = "edit"
            text: "Back"
            pos: root.x, root.top - (2.25*(self.height))

Answer 1

当您使用bind()时，传递的第一个参数是发出事件的实例，因此在您的情况下实例是Button，然后我们可以访问id：

def changer(self, instance):
    print(instance.id)