Question

我有一个使用kivy语言的python脚本，在这里我想不断更新屏幕的元素。

我写了一个代码，显示文件夹中的当前文件。我从github kivy页面上找到了一个示例，但是，该示例不是使用.kv文件开发的，主要原因是因为我必须将其添加到以.kv文件启动的另一个项目中。

如何翻译此代码以使其与.kv文件配合使用？。

这是我的代码，当前没有.kv文件即可工作：

# -*- coding: utf-8 -*-
from kivy.uix.listview import ListView
from kivy.uix.floatlayout import FloatLayout
from kivy.clock import Clock
from kivy.adapters.listadapter import ListAdapter
from kivy.adapters.models import SelectableDataItem
import subprocess
from kivy.uix.listview import ListItemButton

import random

class DataItem(SelectableDataItem):
    def __init__(self, name, **kwargs):
        self.name = name
        super(DataItem, self).__init__(**kwargs)


class MainView(FloatLayout):
    """
    Implementation of a ListView using the kv language.
    """

    list_2 = []

    def __init__(self, **kwargs):
        super(MainView, self).__init__(**kwargs)

        data_items = []

        list_item_args_converter = lambda row_index, obj: {'text': obj.name,
                                                       'size_hint_y': None,
                                                       'height': 25}

        self.list_adapter = \
                ListAdapter(data=data_items,
                        args_converter=list_item_args_converter,
                        selection_mode='single',
                        propagate_selection_to_data=False,
                        allow_empty_selection=False,
                        cls=ListItemButton)

        self.list_view = ListView(adapter=self.list_adapter)

        self.add_widget(self.list_view)

        self.toggle = 'adding'

        Clock.schedule_interval(self.update_list_data, 1)

    def update_list_data(self, dt):
        list_1 = []
        index = -1

        out = subprocess.check_output("ls /home/pi/Documents/myRoutes", shell = True)   
        sp = out.split(".xlsx")

        for i in range(len(sp)):
            if(sp[i] != '\n'):
                list_1.append(sp[i].strip())
        if len(list_1) > len(MainView.list_2):
            for i in list_1:
                for x in MainView.list_2:
                    if i == x: #in x:
                        #print("item from list 1 {} is in list 2 {}".format(i, x))
                        break
                else:
                    #print("item from list 1 {} is NOT in list 2".format(i))
                    items = self.list_adapter.data
                    item = DataItem(i)
                    items.append(item)
                    MainView.list_2.append(i)

        if len(list_1) < len(MainView.list_2):
            print("current is smaller ")
            for i in MainView.list_2: # list 1
                for x in list_1:    # list 2
                    if i == x: #in x: 
                        index += 1
                        #print("item from list 1 {} is in list 2 {} and the index is {}".format(i, x, index))
                        break
                else:
                    index += 1
                    print("item from list 1 {} is NOT in list 2 and I have to delete it and the index is {}".format(i,index))
                    items = self.list_adapter.data
                    item = DataItem(i)
                    del items[index]
                    del MainView.list_2[index]

        print("new {}".format(list_1))
        print("")
        print("old {}".format(MainView.list_2))
        print("")


if __name__ == '__main__':
    from kivy.base import runTouchApp
    runTouchApp(MainView(width=800))

如果发现有帮助，此代码可以在列表中为您提供文件夹中具有特定扩展名的元素。致以诚挚的问候，我希望能获得任何线索以了解如何做到这一点。

Answer 1

在youtube上尝试使用本教程中的示例后：Kivy Tutorial 4: Kivy ListView & ListAdapter

这是我要完成的工作代码。 studentdb.py：

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


class StudentListButton(ListItemButton):
    pass


class StudentDB(BoxLayout):

student_list = ObjectProperty()
cnt = 0

list_2 = []
def __init__(self, **kwargs):
    super(StudentDB, self).__init__(**kwargs)
    Clock.schedule_interval(self.update_list_data, 1)

def update_list_data(self, dt):
    list_1 = []
    index = -1

    #out = subprocess.check_output("ls /home/username/Documents/myRoutes", shell=True)  # test for Lubuntu
    out = subprocess.check_output("ls /home/pi/Documents/myRoutes", shell=True)  # test for RPi
    sp = out.split(".xlsx")


    for i in range(len(sp)):
        if(sp[i] != '\n'):
            list_1.append(sp[i].strip())
    if len(list_1) > len(StudentDB.list_2):
        for i in list_1:
            for x in StudentDB.list_2:
                if i == x:  # in x:
                    #print("item from list 1 {} is in list 2 {}".format(i, x))
                    break
            else:
                #print("item from list 1 {} is NOT in list 2".format(i))
                self.student_list.adapter.data.extend([i])
                StudentDB.list_2.append(i)

    if len(list_1) < len(StudentDB.list_2):
        print("current is smaller ")
        for i in StudentDB.list_2: # list 1
            for x in list_1:    # list 2
                if i == x: #in x: 
                    index += 1
                    #print("item from list 1 {} is in list 2 {} and the index is {}".format(i, x, index))
                    break
            else:
                index += 1
                print("item from list 1 {} is NOT in list 2 and I have to delete it and the index is {}".format(i,index))
                selection = i
                self.student_list.adapter.data.remove(selection)
                del StudentDB.list_2[index]

studentdb.kv：

# Reference studentdb.py
#: import main studentdb
#: import ListAdapter kivy.adapters.listadapter.ListAdapter
#: import ListItemButton kivy.uix.listview.ListItemButton

StudentDB:

<StudentDB>:
    orientation: "vertical"

    student_list: students_list_view
    padding: 10
    spacing: 10

    BoxLayout:
        size_hint_y: None
        height: "40dp"

    BoxLayout:
        size_hint_y: None
        height: "40dp"

    # Define starting data and point to the ListItemButton
    # in the Python code
    ListView:
        id: students_list_view
        adapter:
            ListAdapter(data = [], cls=ListItemButton)

如何转换此代码以使用.kv文件？

1 个答案: