問(wèn)題描述

我正在嘗試為布局創(chuàng)建一個(gè)模板，如下所示:

I'm trying to create a template for a layout which looks like the following:

|----------|
|          | 
| IMAGE    |   <--- Just an image (square)
|          |
|----------| 
|[btn][btn]|   <--- GridLayout cols=2 of buttons 
|[btn][btn]| 
|[btn][btn]| 
|[btn][btn]| 
|[btn][btn]| 
|[btn][btn]|
|----------|

第一部分很簡(jiǎn)單(但我可能錯(cuò)了，因?yàn)槲沂?kivy 的新手)

the first part is easy (but I could be wrong, as I'm very new at kivy)

#:kivy 1.6
[SideBar@BoxLayout]:
    orientation: 'vertical'
    Image:
        source: ctx.image
        size_hint: (1, None)
        height: root.width
    GridLayout:
        cols: 2
        # What do I do here to make it easy to load a list of buttons?

推薦答案

#!/usr/bin/env python2
from kivy.app import App
from kivy.lang import Builder
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.button import Button

Builder.load_string('''
#:kivy 1.6
[SideBar@BoxLayout]:
    content: content
    orientation: 'vertical'
    size_hint: ctx.size_hint if hasattr(ctx, 'size_hint') else (1, 1)
    Image:
        source: ctx.image
        size_hint: (1, None)
        height: root.width
    GridLayout:
        cols: 2
        # just add a id that can be accessed later on
        id: content

<Root>:
    Button:
        center_x: root.center_x
        text: 'press to add_widgets'
        size_hint: .2, .2
        on_press:
            # what comes after `:` is basically normal python code
            sb.content.clear_widgets()
            # however using a callback that you can control in python
            # gives you more control
            root.load_content(sb.content)
    SideBar:
        id: sb
        size_hint: .2, 1
        image: 'data/images/image-loading.gif'
''')

class Root(FloatLayout):

    def load_content(self, content):
        for but in range(20):
            content.add_widget(Button(
                                text=str(but)))

class MyApp(App):
    def build(self):
        return Root()

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

我希望內(nèi)聯(lián)注釋使示例足夠清晰.在這種情況下，我們只是將內(nèi)容的 ref 傳遞給將小部件添加到內(nèi)容的函數(shù).

I hope the inline comments make the example clear enough. In this case we are just passing the ref of the content to the function that adds widgets to the content.

在某些情況下，您可能希望訪問(wèn) Widget 作為您自己類的屬性.在這種情況下，您可以使用以下 方法.

There are situations where you might want to have access to the Widget as a attribute of your own class. In that case you can Use the following method.

上面的方法基本上是加了一個(gè)ObjectProperty的與 id 同名，將 id 所引用的小部件的引用傳遞給它.因此，您現(xiàn)在擁有一個(gè)與 python 類中的 id 同名的屬性，以便于訪問(wèn).使用上述方法，您的代碼將如下所示.

The method above basically adds a ObjectProperty of the same name as the id, passes the reference of the widget referenced to by the id to it. So you, now have a attribute with the same name as the id in your python class for easy access. Using the above mentioned method your code would look something like this.

#!/usr/bin/env python2
from kivy.app import App
from kivy.lang import Builder
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.button import Button
from kivy.properties import ObjectProperty

Builder.load_string('''
#:kivy 1.6
[SideBar@BoxLayout]:
    content: content
    orientation: 'vertical'
    size_hint: ctx.size_hint if hasattr(ctx, 'size_hint') else (1, 1)
    Image:
        source: ctx.image
        size_hint: (1, None)
        height: root.width
    GridLayout:
        cols: 2
        # just add a id that can be accessed later on
        id: content

<Root>:
    content: sb.content
    Button:
        center_x: root.center_x
        text: 'press to add_widgets'
        size_hint: .2, .2
        on_press:
            sb.content.clear_widgets()
            root.load_content()
    SideBar:
        id: sb
        size_hint: .2, 1
        image: 'data/images/image-loading.gif'
''')

class Root(FloatLayout):

    content = ObjectProperty(None)
    '''This is initialised to None and in kv code at line 28
    above (the one with `content: sb.content`) a ref to the
    actual content is passed'''

    def load_content(self):
        content = self.content
        for but in range(20):
            content.add_widget(Button(
                                text=str(but)))

class MyApp(App):
    def build(self):
        return Root()

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

這篇關(guān)于具有動(dòng)態(tài)網(wǎng)格布局的 Kivy 模板的文章就介紹到這了，希望我們推薦的答案對(duì)大家有所幫助，也希望大家多多支持html5模板網(wǎng)！