Kivy: How to merge cells and interact with MySQL database

问题

Here is the relevant snippet of my mykv.kv file:

<RemoveScreen>:
    MyLayout:
        MyLogo:
            GridLayout:
                rows: 6
                cols: 2
                padding: 100,80,100,80
                Label:
                    font_size: "20sp"
                    bold: True
                    color: [1,1,0,1]
                    text: "Part number:"
                Label:
                    text: "Box 02"  
                Label:
                    font_size: "20sp"
                    bold: True
                    color: [1,1,0,1]
                    text: "Part description:"
                Label:
                    text: "Box 04"  
                Label:
                    font_size: "20sp"
                    bold: True
                    color: [1,1,0,1]
                    text: "Quatity on hand:"
                Label:
                    #font_size: "20sp"
                    text: "Box 06"
                Label:
                    font_size: "20sp"
                    bold: True
                    color: [1,1,0,1]
                    text: "Bin location:"   
                Label:
                    text: "Box 08"
                Label:
                    font_size: "20sp"
                    bold: True
                    color: [1,1,0,1]
                    text: "Direction:"  
                Label:
                    text: "Box 10"
                Label:
                    font_size: "20sp"
                    bold: True
                    color: [1,1,0,1]
                    text: "Scan time:"
                Label:
                    text: "Box 12"


        MyButtons:
            #buttons

The code above outputs this:

I would like to have a merged cell on top, where it is center justified,the left column be right justified, and the right column be left justified. the left column will obtain the strings from a MySQL query, and replace the "Box #" strings, looking like:

Questions: Could you please implement in to my code that will:

• Merge the first row of two cells into one
• Right justify the left column
• Left justify the right column (as per the layout above)

回答1:

In kivys GridLayout, there is no feature to join cells. But you could do a work around this, to make it look like that.
In kivy it is easy to combine layouts. And you can nest them as much as you want
So a vertical boxlayout, with 2 elements in it, could be the workaround for this problem.

vertical BoxLayout
    Head Label  
    GridLayout

I will show you an example here.

The python file is just a minimal app.

from kivy.app import App

from kivy.lang import Builder
from kivy.uix.boxlayout import BoxLayout

Builder.load_file("kv.kv")


class RemoveScreen(BoxLayout):
    pass


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


MyApp().run()

And the kv.kv file. To make the code cleaner, I made custom Label classes. That way you only need to change values at one place.

<MyLabel1@Label>:
    font_size: "20sp"
    bold: True
    color: [1,1,0,1]
    halign: "right"
    text_size: root.width, None
    size: self.texture_size


<MyLabel2@Label>:
    halign: "left"
    text_size: root.width, None
    size: self.texture_size


<RemoveScreen>:
    orientation: "vertical"

    MyLabel1:
        text: "Headline"
        size_hint: (1,0.05)
        halign: "center"

    GridLayout:
        rows: 6
        cols: 2
        padding: [0, 0, 0, 25]
        spacing: [10,0]

        MyLabel1:
            text: "Part number:"
        MyLabel2:
            text: "Box 02"  

        MyLabel1:
            text: "Part description:"
        MyLabel2:
            text: "Box 04"  

        MyLabel1:
            text: "Quatity on hand:"
        MyLabel2:
            text: "Box 06"

        MyLabel1:
            text: "Bin location:"   
        MyLabel2:
            text: "Box 08"

        MyLabel1:
            text: "Direction:"  
        MyLabel2:
            text: "Box 10"

        MyLabel1:
            text: "Scan time:"
        MyLabel2:
            text: "Box 12"

来源：https://stackoverflow.com/questions/38779737/kivy-how-to-merge-cells-and-interact-with-mysql-database