Kivy：未知类< ListView >错误代码

Question

这是main.py文件

from kivy.app import App
    
    
class WeatherApp(App):
    pass
    
    
if __name__ == '__main__':
    WeatherApp().run()

weather.kv是:

AddLocationForm:
    
<AddLocationForm@BoxLayout>:
    orientation: 'vertical'
    BoxLayout:
        TextInput:
        Button:
            text: "Search"
        Button:
            text: "Current Location"
    ListView:
        item_strings: ["Palo Alto, MX", "Palo Alto, US"]

它似乎无法识别listview。我看到其他人使用了 "from kivy.uix.listview import ListView" 导入listview，但这也不起作用，我不知道为什么。

kivy.factory.FactoryException: 未知类

- Clumsy Eel

---

ListView在最新的稳定版Kivy 1.11.0中已被弃用或移除。请改用RecycleView。 - ikolim

Answer 1

Kivy 列表视图 » 已弃用

最近发布的稳定版 Kivy 1.11.0 中不再定义 ListView。

Kivy 循环视图 » MVC（模型-视图-控制器）

视图通过处理data生成，它本质上是一个字典列表，并使用这些字典根据需要生成viewclass的实例。其设计基于MVC（模型-视图-控制器）模式。

• 模型：模型由您通过字典列表传递的data组成。
• 视图：视图分为布局和视图，使用适配器实现。
• 控制器：控制器确定逻辑交互，由RecycleViewBehavior实现。

解决方案

要创建一个可选择项目的RecycleView，请将以下类作为viewclass的一部分实现。该项通常是一个小部件，例如Label，Button或布局中的一组/行小部件（BoxLayout或GridLayout）。

viewclass

• 可选择的回收布局类，例如SelectableRecycleBoxLayout()或SelectableRecycleGridLayout()
• 可选择的小部件类，例如SelectableLabel()，SelectableButton()或SelectableRow()

数据

• 创建一个包含data的字典列表

示例

以下示例使用RecycleView演示了ListView的等效性。viewclass是可选择的RecycleBoxLayout，其中包含Label小部件。该应用程序使用OpenWeatherMap的API来检索伦敦，GB（大不列颠）的样本天气数据。

注意：

如果您想使用真实的API点拨打OpenWeatherMap电话，则需要 API密钥（APPID）。

main.py

from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.recycleview.views import RecycleDataViewBehavior
from kivy.uix.label import Label
from kivy.properties import BooleanProperty, ObjectProperty
from kivy.uix.recycleboxlayout import RecycleBoxLayout
from kivy.uix.behaviors import FocusBehavior
from kivy.uix.recycleview.layout import LayoutSelectionBehavior
from kivy.network.urlrequest import UrlRequest
from kivy.lang import Builder

import json


class SelectableRecycleBoxLayout(FocusBehavior, LayoutSelectionBehavior,
                                 RecycleBoxLayout):
    ''' Adds selection and focus behaviour to the view. '''


class SelectableLabel(RecycleDataViewBehavior, Label):
    ''' Add selection support to the Label '''
    index = None
    selected = BooleanProperty(False)
    selectable = BooleanProperty(True)

    def refresh_view_attrs(self, rv, index, data):
        ''' Catch and handle the view changes '''
        self.index = index
        return super(SelectableLabel, self).refresh_view_attrs(
            rv, index, data)

    def on_touch_down(self, touch):
        ''' Add selection on touch down '''
        if super(SelectableLabel, self).on_touch_down(touch):
            return True
        if self.collide_point(*touch.pos) and self.selectable:
            return self.parent.select_with_touch(self.index, touch)

    def apply_selection(self, rv, index, is_selected):
        ''' Respond to the selection of items in the view. '''
        self.selected = is_selected


class AddLocationForm(BoxLayout):
    search_input = ObjectProperty()
    search_results = ObjectProperty()

    def search_location(self):
        search_template = "https://samples.openweathermap.org/data/2.5/find?q={}&appid=b6907d289e10d714a6e88b30761fae22"
        # search_template = "https://api.openweathermap.org/data/2.5/find?q={}&typle=like&appid=xyz"    # Replace 'xyz' with your API Key (APPID)
        search_url = search_template.format(self.search_input.text)
        request = UrlRequest(search_url, self.found_location)

    def found_location(self, request, data):
        data = json.loads(data.decode()) if not isinstance(data, dict) else data
        cities = ["{} ({})".format(d['name'], d['sys']['country']) for d in data['list']]
        self.search_results.data = [{'text': str(x)} for x in cities]
        print(f"self.search_results.data={self.search_results.data}")


class WeatherRoot(BoxLayout):
    pass


class TestApp(App):
    title = "Weather App"

    def build(self):
        return Builder.load_file("main.kv")


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

main.kv

WeatherRoot:

<WeatherRoot>:
    AddLocationForm:

<SelectableLabel>:
    # Draw a background to indicate selection
    canvas.before:
        Color:
            rgba: (1, 0, 0, 1) if self.selected else (.0, 0.9, .1, .3)
        Rectangle:
            pos: self.pos
            size: self.size
        Color:
            rgba: (0, 0.9, .1, .3)
        Rectangle:
            pos: self.pos
            size: self.size

<AddLocationForm>:
    orientation: "vertical"

    search_input: search_input
    search_results: search_results_list

    BoxLayout:
        height: "40dp"
        size_hint_y:None

        TextInput:
            id: search_input
            size_hint_x: 50
            focus: True
            multiline: False
            hint_text: 'Your city name'
            on_text_validate: root.search_location()


        Button:
            text: "Search"
            size_hint_x: 25
            on_press: root.search_location()

        Button:
            text: "Current Location"
            size_hint_x: 25

    RecycleView:
        id: search_results_list

        viewclass: 'SelectableLabel'

        SelectableRecycleBoxLayout:
            default_size: None, dp(26)
            default_size_hint: 1, None
            size_hint_y: None
            height: self.minimum_height
            orientation: 'vertical'
            multiselect: True
            touch_multiselect: True

输出

- ikolim

Answer 2

我用以下方法解决了这个问题：

main.py

from kivy.app import App 
from kivy.uix.recycleview import RecycleView

class RV(RecycleView):
    def __init__(self, **kwargs):
        super(RV, self).__init__(**kwargs)
        self.data = [{'text': str(values)} for values in ["Palo Alto, MX", "Palo Alto, US"]]


class WeatherAPP(App):
    pass

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

weather.kv

#:kivy 1.10
AddLocationForm:

<AddLocationForm@BoxLayout>:
    orientation: 'vertical'
    BoxLayout:
        TextInput:
        Button:
            text: "Search"
        Button:
            text: "Current Location"
    RV:
        viewclass: 'Label'
        RecycleBoxLayout:
            default_size: None, dp(56)
            default_size_hint: 1, None
            size_hint_y: None
            height: self.minimum_height
            orientation: 'vertical'

- Pablo Sierra