Kivy从Stack-/GridLayout中删除元素 [英] Kivy Removing elements from a Stack- / GridLayout

问题描述

我弹出了一个窗口.基本上是一些选项行(最多5行).

I made a pop-up. It is basically some rows of options (max. 5 rows).

如果我按下"+"按钮，将会有新的选项行.

If I press the '+' button, there will be a new line of options.

如果我按下-"按钮，则最后一行将消失.不幸的是，不是.

If I press the '-' button the last row should diasappear. Unfortunatelly it doesn't.

我已经在root.remove()中尝试了以下方法:

I tried already the followings out in root.remove():

-> widget_path.pop(0): 没有视觉变化，我看到的是n行而不是n-1.

--> widget_path.pop(0) : no visual change, I see n rows instead of n-1 .

-> widget_path.pop(): 它将删除第一行而不是最后一行.

--> widget_path.pop() : It removes the first line instead of the last one.

-> Gridlayout(列数:4)而不是StackLayout:相似的结果

--> Gridlayout (cols: 4) instead of StackLayout: similar results

你能帮我吗?

这是我的代码:

.kv -file;

.kv -file;

<FormPopup>:
    size_hint: None, None
    size: '361pt', '220pt'
    BoxLayout:
        orientation: 'vertical'

    BoxLayout:
        size_hint: 1, None
        height: '20pt'
        orientation: 'horizontal'
        Label:
            text: 'column1'
        Label:
            text: 'column2'
        Label:
            text: 'column3'
        Label:
            text: 'column4'
        # list of sensors
        StackLayout:
            padding: 0
            spacing: 1
        orientation: 'lr-tb'
        pos_hint: {'center_x': .5, 'center_y': .5}
                height: self.minimum_height
                id: measure_stack

        BoxLayout:
        orientation: 'horizontal'
            MyButton:
                text: '+'
                    on_release: root.add()
            MyButton:
                    text: '-'
                    on_release: root.remove()

我的.py类:

class FormPopup(Popup):
    """Class: Popup for comments"""
    def __init__(self):
        super().__init__()
        self.error = 0
        self.linenumber = 0
        self.add()

    def add(self):
        """add a new option-line"""
        widget_path = self.ids
        if self.linenumber < 5 :
            sensor_id = 'sensor_' + str(self.linenumber)
            widget_path['measure_stack'].add_widget(Spinner(id = sensor_id, size_hint=(None,None), height='20pt', width='85pt', text = '---', values= ('A','B','C') ))
            measurand_id = 'measurand_' + str(self.linenumber)
            widget_path['measure_stack'].add_widget(Spinner(id = measurand_id, size_hint=(None,None), height='20pt', width='85pt', text = '---', values= ('A','B','C') ) )
            branchwise_id = 'branchwise_' + str(self.linenumber)
            widget_path['measure_stack'].add_widget(Spinner(id = branchwise_id, size_hint=(None,None), height='20pt', width='85pt', text = '---', values= ('A','B','C')))
            procedure_id = 'procedure_' + str(self.linenumber)
            widget_path['measure_stack'].add_widget(Spinner(id = procedure_id, size_hint=(None,None), height='20pt', width='85pt', text = '---', values= ('A','B','C'))) 
            self.linenumber += 1

    def remove(self):
        """remove one option-line"""
        widget_path = self.ids.measure_stack.children
        # do not remove if there is only one line
        if len(widget_path) > 4:
            self.linenumber -= 1
            for i in range(4):
                widget_path.pop(0)

推荐答案

获取小部件，然后将其删除.
一个例子:

Get the widget, and remove it.
An example of that:

from kivy.app import App
from kivy.lang import Builder


root = Builder.load_string('''

BoxLayout:
    GridLayout:
        id: grid
        cols: 1
        rows: 5
        Label:
            text: "label 1"
        Label:
            text: "label 2"
        Label:
            text: "label 3"
        Label:
            text: "label 4"

    Button:
        text: "Remove last item"
        on_release: grid.remove_widget(grid.children[0])

''')



class MyApp(App):

    def build(self):
        return root

MyApp().run()

这篇关于Kivy从Stack-/GridLayout中删除元素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IT屋！