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问题：

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

目标：

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，我希望从def changer(self, *args)方法中打印该 id

问题：

正如您从提供的代码中可能猜到的那样，我只能打印最后创建的按钮的 ID（“测试 3”）。

蟒蛇代码：

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()

千伏代码：

#: 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))
4

1 回答 1

1

when you use bind(), the first parameter that passes is the instance that issues the event, so in your case instance is the Button, and then we can access the id:

def changer(self, instance):
    print(instance.id)
于 2018-03-15T00:06:01.877 回答