如何从kivy文件(.kv)访问不同类的id/widget？

Question

我想知道什么？

1. 如果释放具有id:button_b(Get_Boys类)的按钮,则必须更改具有id:label_g(Get_Girls类)的Label.
2. 如果按下具有id:button_b(Get_Boys类)的Button,则必须更改具有id:root_lbl(Get_People类)的Label.
3. 如果释放了具有id:root_btn(Get_People类)的Button,则必须更改具有id:label_b(Get_Boys类)的Label.

在这个链接中解释(很少),但不是从初学者的角度来解释.

我有2个文件

1. test.py
2. dates_test.kv

test.py

class Get_People(BoxLayout):
    pass

class Get_Boys(BoxLayout):
    pass

class Get_Girls(BoxLayout):
    pass

class TestApp(App):
    def build(self):
        self.load_kv('dates_test.kv')
        return Get_People()

dates_test.kv文件

<Get_People>:
    orientation: 'vertical'
    Button:
        name: root_btn
        id: root_btn
        text: "I am Root Button"
        on_release: change_label_b
    Label:
        id: root_lbl
        text: "I am Root Label"
    Get_Boys:
    Get_Girls:

<Get_Boys>:
    Button:
        id: button_b
        text: "Button for boys"
        on_press: change_label_root
        on_release: change_label_g
    Label:
        id: label_b
        text: "Label for boys"

<Get_Girls>:
    Button:
        id: button_g
        text: "Button for girls"
    Label:
        id: label_g
        text:"Label for girls"

Answer 1

好吧!看起来我自己找到了答案,我想分享一下.

首先让我们在dates_test.kv文件中给出"id".这样您就可以在python代码或.kv文件中访问它们.

<Get_People>:
    stuff_p: root_lbl
    ...
    Get_Boys:
        id: gb
    Get_Girls:
        id: gg

<Get_Boys>:
    stuff_b: label_b

<Get_Girls>:
    stuff_c: label_g

你可能想知道什么是stuff_p,stuff_b和stuff_c ???

它们是在自己的类中定义的ObjectProperty.你在python代码中的stuff_b中所做的更改会在label_b中进行更改,因为你已经在kivy文件中进行了链接.

class Get_People(BoxLayout):
    stuff_p = ObjectProperty(None)
    ...

class Get_Boys(BoxLayout):
    stuff_b = ObjectProperty(None)
    ...

class Get_Girls(BoxLayout):
    stuff_c = ObjectProperty(None)
    ...

对于第1部分和第2部分

1. 如果释放具有id:button_b(Get_Boys类)的按钮,则必须更改具有id:label_g(Get_Girls类)的Label.

2. 如果按下具有id:button_b(Get_Boys类)的Button,则必须更改具有id:root_lbl(Get_People类)的Label.

在Get_Boys类(test.py)中定义这些方法.

def change_girl(self):

    self.parent.ids.gg.stuff_c.text = "Boys changed Girls!"
    #self.stuff_b.text = "i changed myself!"

def change_people(self):
    self.parent.ids.root_lbl.text = "Boys changed people!"

让我们看看这里发生了什么......

self.parent.ids.gg.stuff_c.text ="男孩改变了女孩!"

1. self.parent指的是Get_Parent类.
2. .ids.gg指的是我们为Get_Girls创建的id.
3. .stuff_c用于在Get_Girls类中引用label_g(上面).
4. .text用于更改标签中的文本.

并在.kv文件中

<Get_Boys>:
    stuff_b: label_b
    Button:
        id: button_b
        text: "button 1"
        on_release: root.change_girl()
        on_press: root. change_people()

第3部分

3. 如果释放了具有id:root_btn(Get_People类)的Button,则必须更改具有id:label_b(Get_Boys类)的Label.

在Get_People类(test.py)中定义一个方法.

def rooted(self):
    self.ids.gb.stuff_b.text = "people changed boys!"

并在.kv文件中

Button:
    id: root_btn
    text: "I am Root"
    on_release: root.rooted()