从 kivy 适配器小部件中删除 ListItemButtons

Question

好的，我正在根据搜索的城市使用 listitembuttons 填充列表。它将使用与输入文本匹配的每个城市的 listitembutton 填充列表。当我进入一个新城市时，我想删除其他列表项按钮并将它们替换为我搜索的新城市列表。我可以使用这段代码删除它们。

def clear_locations(self):
        for x in self.search_results.adapter.data:
            self.search_results.adapter.data.remove(x)

如果我使用此函数打印 x in self.search_results.adapter.data：例如，当我搜索伦敦时：它将打印出四个城市，每个城市都有自己的 ListItemButton。但是，它只删除与创建的新按钮数量相等的 ListItemButtons 数量。

假设我首先搜索 london 并获得四个 listitembuttons。然后我搜索巴黎。它删除了两个 london listitembuttons 并添加了两个 paris 。如果我搜索 murfreesboro，它将删除一个 london listitembuttons 并添加一个 murfreesboro 一个。我没有得到的是，四个循环将遍历并打印数据中的所有城市，但只会删除等于新城市数量的数量。任何帮助都会很棒。

这是我的其余代码： main.py

from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.properties import ObjectProperty, ListProperty, StringProperty, NumericProperty
from kivy.network.urlrequest import UrlRequest
import json
from kivy.adapters.listadapter import ListAdapter
from kivy.uix.listview import ListItemButton

class WeatherRoot(BoxLayout):

    location_form = ObjectProperty()
    current_weather = ObjectProperty()

    def show_current_weather(self, location=None):
        self.clear_widgets()

        if location is not None:
            self.current_weather = CurrentWeather(location=location)

        if self.current_weather is None:
            self.current_weather = CurrentWeather()

        if location is None:
            self.current_weather.location = location

        self.current_weather.update_weather()    
        self.add_widget(self.current_weather)

    def add_location(self):
        self.clear_widgets()
        self.add_widget(self.location_form)

class CurrentWeather(BoxLayout):
    location = ListProperty(["NewYork", "US"])
    conditions = StringProperty()
    temp = NumericProperty()
    temp_min = NumericProperty()
    temp_max = NumericProperty()
    wind = NumericProperty()
    humidity = NumericProperty()

    def update_weather(self):
        weather_template = "http://api.openweathermap.org/data/2.5/weather?q={},{}&units=imperial&APID=a1bf58ef2e81e600af117e12e13e0ff1"
        weather_url = weather_template.format(*self.location)
        request = UrlRequest(weather_url, self.weather_retrieved)

    def weather_retrieved(self, request, data):
        self.conditions = data['weather'][0]['description']
        self.temp = data['main']['temp']
        self.temp_min = data['main']['temp_min']
        self.temp_max = data['main']['temp_max']
        self.wind = data['wind']['speed']
        self.humidity = data['main']['humidity']

class LocationButton(ListItemButton):
    location = ListProperty()

class AddLocationForm(BoxLayout):

    search_input = ObjectProperty() 
    search_results = ObjectProperty()

    def args_converter(self, index, data_item):
        (city, country) = data_item
        return {'location':(city,country)} 

    def web_error(self, *args, **kwargs):
        self.search_results.data = ["Either the openweather.org is down", "or you are not connected to the interweb"]

    def clear_locations(self):
        for x in self.search_results.adapter.data:
            self.search_results.adapter.data.remove(x)


    def search_location(self):
        self.clear_locations()      
        search_template = "http://api.openweathermap.org/data/2.5/find?q={}&type=like&APID=a1bf58ef2e81e600af117e12e13e0ff1"
        search_url = search_template.format(self.search_input.text)
        request = UrlRequest(search_url, self.found_location, on_error=self.web_error)


    def found_location(self, request, data):
        try:
            cities = [(d['name'], d['sys']['country']) for d in data['list']]
        except:
            cities = ["No",  "Citys Found"]
        self.search_results.adapter.data[:]
        self.search_results.adapter.data.extend(cities)
        self.search_results._trigger_reset_populate()



class WeatherApp(App):
    pass

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

天气.kv

#: import main main
#: import ListAdapter kivy.adapters.listadapter.ListAdapter

WeatherRoot:


<WeatherRoot>:
    location_form: add_location_form
    AddLocationForm:
        id: add_location_form

<LocationButton>:
    text: "{}({})".format(self.location[0], self.location[1])
    size_hint_y: None
    height: "40dp"
    color: [1, 1, 1, 1]
    deselected_color: 0,.8,.5,1
    on_press: app.root.show_current_weather(self.location)

<CurrentWeather>:
    orientation: 'vertical'
    Label:
        text: "{}({})".format(root.location[0], root.location[1])
    Label:
        text: root.conditions
    Label:
        text: "Current Temp: {}".format(root.temp)
    Label:
        text: "Low: {}".format(root.temp_min)
    Label:
        text: "High: {}".format(root.temp_max)
    Label:
        text: "Wind Speed: {}".format(root.wind)
    Label:
        text: "Humiditity: {}".format(root.humidity)
    BoxLayout:
        orientation: 'horizontal'
        size_hint_y: None
        height: "40dp"
        Button:
            text: "Add Location"
            on_press: app.root.add_location()
        Button:
            text: "Forcast"

<AddLocationForm>:
    orientation: 'vertical'
    search_input: search_box
    search_results: search_results_list
    BoxLayout:
        size_hint_y: None
        height: "40dp"
        TextInput:
            id: search_box
            focus: True
            multiline: False
            size_hint_x: 50
            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

    ListView:
        id: search_results_list
        adapter:
            ListAdapter(data = [], cls = main.LocationButton, args_converter = root.args_converter)

因此，如果我在搜索伦敦后搜索巴黎时使用 for 循环在 self.search_results.adapter.data 中打印 x，我会在控制台中得到：

(u'London', u'CA')
(u'London', u'GB')
(u'London Borough of Harrow', u'GB')
(u'Londonderry County Borough', u'GB')

但是如果我在 self.search_results.adapter.data: 中对 x 使用 remove(x) ，那么我在搜索伦敦后搜索巴黎时会得到这个：

Answer 1

更新！找到了一个很好的解决方案！

如果其他人有这个问题，我用

解决了

def clear_locations(self):
    del self.search_results.adapter.data[:]