如何从视图类作为按钮的 RecyclerView 获取实例？

Question

我有一个键盘应用程序，它从 RecycleView 加载 9 个按钮，Viewclass 在 RecycleGridLayout 中设置为 Button。 主要问题是当按钮添加为 Viewclass 时，我无法获得按钮的实例。但是如果我将按钮作为小部件添加到普通 GridLayout.

，我可以获得按钮的实例

这是我无法从中获取按钮实例的 RecycleView 代码：

import kivy
kivy.require('1.10.0')

from kivy.app import App
from kivy.uix.floatlayout import FloatLayout
from kivy.lang import Builder
from kivy.properties import ObjectProperty

Builder.load_string('''
<myKeyPad>:
    show_input: show_input
    TextInput:
        id: show_input
        hint_text: 'Type number'
        pos_hint: {'x': 0.05,'top': 0.98}
        size_hint: [0.9,0.1]
        font_size: self.height / 1.7
    RecycleView:
        id: view_keypad
        viewclass: 'Button'
        pos_hint: {'x': 0.35,'top': 0.86}
        size_hint: [1,1]
        RecycleGridLayout:
            cols: 3
            defualt_size: [None, 20]
            defualt_size_hint: [1, 0.2]

''')
class myKeyPad(FloatLayout):
    show_input = ObjectProperty(None)
    def __init__(self, **kwargs):
        super().__init__(**kwargs)
        btn = ['7','8','9','4','5','6','1','2','3','*','0','#']
        key_padbtns=[]
        for b in btn:
            if b=='#':
                key_padbtns.append({'text':b, 'on_press':self.process_output})
            else:
                key_padbtns.append({'text':b, 'on_press':self.get_input})
        self.ids.view_keypad.data = key_padbtns
    def get_input(self,instance):
        the_input = (instance.text)
        i_no = self.show_input
        i_no.text = i_no.text + the_input
    def process_output(self):
        the_output = self.show_input.text
        self.show_input.text = ''
        print(the_output)
class theKeyPadApp(App):
    title='Keypad Input'
    def build(self):
        return myKeyPad()

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

从这段代码我可以得到实例：

import kivy
kivy.require('1.10.0')

from kivy.app import App
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.button import Button
from kivy.lang import Builder
from kivy.properties import ObjectProperty

Builder.load_string('''
<myKeyPad>:
    show_input: show_input
    TextInput:
        id: show_input
        hint_text: 'Type number'
        pos_hint: {'x': 0.05,'top': 0.98}
        size_hint: [0.9,0.1]
        font_size: self.height / 1.7
    GridLayout:
        cols: 3
        id: view_keypad
        pos_hint: {'x': 0.05,'top': 0.86}
        size_hint: [0.9,0.5]

''')
class myKeyPad(FloatLayout):
    show_input = ObjectProperty(None)
    def __init__(self, **kwargs):
        super().__init__(**kwargs)
        btn = ['7','8','9','4','5','6','1','2','3','*','0','#']
        print(btn)
        key_padbtns=[]
        for b in btn:
            if b=='#':
                key_padbtns.append(Button(text=b, on_press=self.process_output))
            else:
                key_padbtns.append(Button(text=b, on_press=self.get_input))

        for k in key_padbtns:
            self.ids.view_keypad.add_widget(k)
    def get_input(self,instance):
        print(instance)
        the_input = (instance.text)
        i_no = self.show_input
        i_no.text = i_no.text + the_input
    def process_output(self):
        the_output = self.show_input.text
        self.show_input.text = ''
        print(the_output)
class theKeyPadApp(App):
    title='Keypad Input'
    def build(self):
        return myKeyPad()

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

如何从视图类为 'Button' 的 RecycleView 中获取按钮对象的属性，即 kivy.uix.button.Button object？

Answer 1

问题

cannot get an instance of the buttons when the buttons is added as a Viewclass.

解决方案

解决方法如下

kv 文件

在 kv 文件中，为 Button class 添加以下 on_press 事件。

片段 - kv 文件

<Button>:
    on_press:
        if self.text == '#': app.root.process_output()
        else: app.root.get_input(self)

Py文件

在Python脚本中，进行如下修改。

片段 - Py 文件

def __init__(self, **kwargs):
    super().__init__(**kwargs)
    btn = ['7', '8', '9', '4', '5', '6', '1', '2', '3', '*', '0', '#']
    key_padbtns = []
    for b in btn:
        key_padbtns.append({'text': b})
    self.ids.view_keypad.data = key_padbtns