问题描述

我正在尝试通过构建一个简单的待办事项列表应用程序来学习 kivy，就像在 Kivy 中创建应用程序"一书的作者 Dusty Phillips 所建议的那样.

I'm trying to learn kivy by building a simple todo-list app like suggested by Dusty Phillips, author of the book "Creating apps in Kivy".

这是目前为止的代码:

from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.properties import ObjectProperty
from kivy.uix.listview import ListItemButton


class TaskButton(ListItemButton):
    pass


class TodoRoot(BoxLayout):
    task_input = ObjectProperty()
    task_list = ObjectProperty()

    def add_task(self):
        self.task_list.adapter.data.extend([self.task_input.text])
        self.task_list._trigger_reset_populate()

    def del_task(self):
        pass


class TodoApp(App):
    def build(self):
        return TodoRoot()


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

这是kv文件:

#: import main todo
#: import ListAdapter kivy.adapters.listadapter.ListAdapter
#: import ListItemButton kivy.uix.listview.ListItemButton

TodoRoot:

<TodoRoot>:
    orientation: "vertical"
    task_input: task_input_view
    task_list: tasks_list_view

    BoxLayout:
        size_hint_y: None
        height: "40dp"

        TextInput:
            id: task_input_view
            size_hint_x: 70
        Button:
            text: "Add"
            size_hint_x: 15
            on_press: root.add_task()
        Button:
            text: "Del"
            size_hint_x: 15
            on_press: root.del_task()
    ListView:
        id: tasks_list_view
        adapter:
            ListAdapter(data=[], cls=main.TaskButton)

这是它的样子:

我知道 ListView API 仍处于试验阶段，我抱怨有关使用适配器/转换器、google &所以搜索也没有帮助.那么需要什么代码才能使 Del-Button 工作并删除选定的 ListItemButton?

I know the ListView API is still somewhat experimental and I'm complaining about the examples on using adapters / converters, google & SO search didn't help either. So what code is needed to make the Del-Button work and remove a selected ListItemButton?

推荐答案

大量阅读 ListView API docs &例子，我终于找到了自己.我们需要的是listadapter-Class的selection-Property，那么我们可以简单的调用adapter.data-ListProperty继承的remove方法.

After a lot of reading ListView API docs & examples, I finally found out myself. What we need is the selection-Property of the listadapter-Class, then we can simply call the inherited remove method of the adapter.data-ListProperty.

所以对于任何有兴趣的人来说，这是代码:

So for anyone interesested this is the code:

def del_task(self, *args):
    if self.task_list.adapter.selection:
        selection = self.task_list.adapter.selection[0].text
        self.task_list.adapter.data.remove(selection)
        self.task_list._trigger_reset_populate()

这篇关于Python Kivy ListView:如何删除选定的 ListItemButton?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持跟版网！