KivyMD:在 python 代码中添加列表小部件,"on_release" - 属性 有问题

KivyMD: Adding list widget inside python code, problem with "on_release" - property

尝试将一些带有 for 循环的按钮添加到已在 .kv 文件中定义的容器中:

代码如下所示:

a_list = ["Spam", "Eggs"]

for i in range(len(a_list)):
    self.ids.container.add_widget(

        ThreeLineListItem(id = a_list[i], text= "Some info ",
                                secondary_text = "More info",
                                tertiary_text = "Final info", 
                          on_release=lambda x: print_me(self.id))
                          )
def print_me(the_id):
    print(the_id)

这只是打印“None”,这是怎么回事?以及如何修复它,以便第一个按钮在发布时打印“垃圾邮件”,第二个按钮打印“鸡蛋”?

from kivy.lang import Builder

from kivymd.app import MDApp
from kivymd.uix.list import OneLineListItem

KV = '''
ScrollView:

    MDList:
        id: box

'''


class Test(MDApp):
    def build(self):
        return Builder.load_string(KV)

    def on_start(self):
        a_list = ["Spam", "Eggs"]
        for name in a_list:
            self.root.ids.box.add_widget(
                OneLineListItem(text=name, on_release=self.print_item)
            )

    def print_item(self, instance):
        print(instance, instance.text)


Test().run()