基维。 GridLayout 在 ScrollView 内的位置答案

【问题标题】：Kivy. Position of GridLayout inside ScrollView基维。 GridLayout 在 ScrollView 内的位置
【发布时间】：2019-08-16 15:46:54
【问题描述】：

我放弃了。我想我已经尽力了。我需要一些解释如何定位嵌套布局类。在下面的代码中，我需要将这些标签定位在屏幕的中心。我试过的任何东西都会在左侧留下Labels。

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

kv = """

<StorageLabel@Label>
    background_normal: ''
    size_hint: None, None
    size: 65, 50
    canvas.before:
        Color:
            rgba: (1, 0, 0.5, 1) 
        Rectangle:
            pos: self.pos
            size: self.size
    halign: "left"
    valign: "middle"    

<Storage@BoxLayout>
    ScrollView:
        size_hint_x: 1
        bar_width: 10
        scroll_type: ['bars', 'content']
        bar_color: [0, 0, 0, 1]
        bar_inactive_color: [0, 0, 0, 1]
        pos_hint: {'center_x': 0.5}
        GridLayout:

            cols: 3
            size_hint_y: None
            size: self.minimum_size
            height: self.minimum_height

            StorageLabel:
                text: '1m'

            StorageLabel:
                text: '2m'

            StorageLabel:
                text: '3m'

Storage:

"""

sm = Builder.load_string(kv)

class Main(App):
    def build(self):
        return sm

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

【问题讨论】：

标签： kivy

【解决方案1】：

使Labels 居中的最简单方法是让GridLayout 调整大小并定位它们。这会导致每个 Label 的 width 更大，但它们是居中的：

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

kv = """

<StorageLabel@Label>
    background_normal: ''
    # leave size_hint_x at default of 1
    size_hint_y: None
    height: 50
    canvas.before:
        Color:
            rgba: (1, 0, 0.5, 1) 
        Rectangle:
            pos: self.pos
            size: self.size

<Storage@BoxLayout>
    ScrollView:
        size_hint_x: 1
        bar_width: 10
        scroll_type: ['bars', 'content']
        bar_color: [0, 0, 0, 1]
        bar_inactive_color: [0, 0, 0, 1]
        pos_hint: {'center_x': 0.5}
        GridLayout:
            cols: 3
            # add some padding and spacing
            padding: 5
            spacing: 5
            size_hint_y: None
            height: self.minimum_height

            StorageLabel:
                text: '1m'

            StorageLabel:
                text: '2m'

            StorageLabel:
                text: '3m'

Storage:

"""

sm = Builder.load_string(kv)

class Main(App):
    def build(self):
        return sm

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

如果您希望标签为原始大小，则可以将每个标签放在自己的Layout（可能是FloatLayout）中，然后让GridLayout 调整大小并定位那些Layouts：

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

kv = """

<StorageLabel@Label>
    background_normal: ''
    size_hint: None, None
    size: 65, 50
    # position the label in the center of its FloatLayout
    pos_hint: {'center_x':0.5}
    canvas.before:
        Color:
            rgba: (1, 0, 0.5, 1) 
        Rectangle:
            pos: self.pos
            size: self.size

<Storage@BoxLayout>
    ScrollView:
        size_hint_x: 1
        bar_width: 10
        scroll_type: ['bars', 'content']
        bar_color: [0, 0, 0, 1]
        bar_inactive_color: [0, 0, 0, 1]
        pos_hint: {'center_x': 0.5}
        GridLayout:
            cols: 3
            size_hint_y: None
            height: self.minimum_height
            # set the default row height to the height of the Labels
            row_default_height: 50

            FloatLayout:
                StorageLabel:
                    text: '1m'

            FloatLayout:
                StorageLabel:
                    text: '2m'

            FloatLayout:
                StorageLabel:
                    text: '3m'

Storage:

"""

sm = Builder.load_string(kv)

class Main(App):
    def build(self):
        return sm

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

【讨论】：