摘要

Question

我有一个删除按钮，可以从另一个页面删除小部件。但是，该按钮实际上并未删除小部件。该按钮还应该删除附加到小部件的json对象，但是它也不会这样做。

代码：

onMessageRender()

    # displays the streak that was clicked on in screen two
    def display_streak(self, obj):
        self.third_screen()
        name = obj.id
        bottle = self.root.get_screen("three")
        can = self.root.get_screen('two')
        bottle.ids.del_space.add_widget(Button(id=name, text="Delete", size=(60,25), size_hint=(None,None),
                                    font_size=18, on_press=self.del_button)) # fix later

我试图将def del_button(self, obj): bottle = self.root.get_screen("two") can = self.root.get_screen('three') name = obj.id with open("streak.json", "r+") as f: data = json.load(f) for child in self.root.screen_two.ids.streak_zone.children: if child.text == name: print("delete") bottle.screen_two.ids.streak_zone.remove_widget(child) for i in xrange(len(data)): if data[i] == name: data.pop(i) break open("streak.json", "w").write(json.dump(data, sort_keys=True, indent=4))中的Button的ID与del_space中的小部件内部的文本进行比较，以便删除，但是由于某些原因，这是行不通的。我什至从streak_zone传递了obj，但它仍然不起作用，怎么来的？

EDIT

on_press=self.del_button中的

obj是从将函数绑定到按钮小部件的条件传递的：

display_streak()

EDIT

我不确定，但是我认为问题可能出在我的奇异代码上：

elif delay > time.time() > self.honey:  # on time (green)
                    child.background_normal = ''
                    child.background_color = [0, 1, 0, .95]
                    child.unbind(on_press=self.early_click)
                    child.bind(on_press=self.add_score)
                    child.bind(on_press=self.display_streak)
                    child.bind(on_press=self.draw_streak)

进入第二页时，<ScreenTwo> id: screen_two name: "two" on_leave: app.restart() on_enter: app.display_btn() ScrollView: GridLayout: cols: 2 rows: 1 ScrollView: BoxLayout: id: streak_zone orientation: 'vertical' height: self.minimum_height被激活

Python：

display_btn

如果这是不删除按钮的原因，那么我该如何解决这个问题？

Answer 1

将child.text替换为child.id
从reversed()的第一个self.root.screen_two.ids.streak_zone.children开始，将child添加到children
从screen_two中删除bottle.screen_two.ids.streak_zone.remove_widget(child)，因为bottle是对象ScreenTwo的实例

摘要

def del_button(self, obj):
        bottle = self.root.get_screen("two")
        can = self.root.get_screen('three')
        name = obj.id

        with open("streak.json", "r+") as f:
            data = json.load(f)

        for child in reversed(bottle.ids.streak_zone.children):
            if child.id == name:
                print("delete")
                bottle.ids.streak_zone.remove_widget(child)

Answer 2

由于kv文件在离开时删除了小部件，所以我只需要删除与小部件具有相同ID的json元素

def del_button(self, object):
        name = object.id

        with open("streak.json", "r") as f:
            data = json.load(f)

        with open("streak.json", "r+") as file:
            data = json.load(file)
            data.pop(name, None)
            file.seek(0)
            json.dump(data, file, indent=4)
            file.truncate()

        self.change_screen()

如何从奇异果中的另一个页面删除小部件

2 个答案:

摘要