Python Kivy的相对布局用法介绍和代码示例 _Kivy

Kivy是Python中与平台无关的GUI工具。由于它可以在Android, IOS, Linux和Windows等操作系统上运行。它基本上是用于开发Android应用程序, 但这并不意味着它不能在桌面应用程序上使用。

Kivy教程–通过示例学习Kivy。

相对布局：

相对布局与FloatLayout区别在于其子窗口小部件相对于布局定位。
此布局的操作方式与FloatLayout相同, 但是定位属性(x, y, center_x, right, y, center_y和top)是相对于Layout大小而不是窗口大小的。
实际上, 无论绝对位置和相对位置如何, 当布局的位置更改时, 小部件都会移动。
将position =(0, 0)的窗口小部件添加到RelativeLayout时, 现在如果RelativeLayout的位置发生了更改, 则子窗口小部件也将移动。子窗口小部件坐标保持不变, 即(0, 0), 因为它们始终相对于父布局。
可用的pos_hint键(x, center_x, right, y, center_y和top)对于对齐边缘或居中很有用。
例如：
pos_hint：{'center_x'：。5, 'center_y'：。5}会将窗口小部件对齐在中间, 而不管窗口的大小如何。

使用RelativeLayout要做的第一件事是导入它。

from kivy.uix.relativelayout import RelativeLayout

注意：
此布局允许你设置子项的相对坐标。如果要绝对定位, 请使用FloatLayout。在RelativeLayout中, 必须指定每个子窗口小部件的大小和位置。这也可以进行动态放置。

We can do relative positioning by: pos_hint: provide hint of position We can define upto 8 keys i.e. it takes arguments in form of dictionary. pos_hint = {"x":1, "y":1, "left":1, "right":1, "center_x":1, "center_y":1, "top":1, "bottom":1("top":0)}

注意：
浮动布局
和
相对布局
两者都支持绝对和相对定位, 具体取决于是否
pos_hint
或pos使用。但是, 如果要绝对定位, 请使用FloatLayout。

Basic Approach to create Relative Layout:1) import kivy 2) import kivyApp 3) import button 4) import Relativelayout 5) Set minimum version(optional) 6) create App class: - define build() function 7) return Layout/widget/Class(according to requirement) 8) Run an instance of the class

使用pos的方法的实现：
它只是将位置分配给按钮。如
相对布局
不依赖于窗口大小, 如果你将窗口大小设置得很小, 它现在会固定在该位置, 它可能会消失而不是自行调整。

# Sample Python application demonstrating the # working of RelativeLayout in Kivy # import modules import kivy # base Class of your App inherits from the App class. # app:always refers to the instance of your application from kivy.app import App # creates the button in kivy # if not imported shows the error from kivy.uix.button import Button # This layout allows you to set relative coordinates for children. from kivy.uix.relativelayout import RelativeLayout# To change the kivy default settings # we use this module config from kivy.config import Config # 0 being off 1 being on as in true / false # you can use 0 or 1 & & True or False Config. set ( 'graphics' , 'resizable' , True ) # creating the App class class MyApp(App): def build( self ): # creating Relativelayout Rl = RelativeLayout() # creating button # a button 30 % of the width and 20 % # of the height of the layout and # positioned at (x, y), you can do # The position does not depend on window size # it just positioned at the given places: btn = Button(text = 'Hello world' , size_hint = (. 2 , . 2 ), pos = ( 396.0 , 298.0 )) btn1 = Button(text = 'Hello world !!!!!!!!!' , size_hint = (. 2 , . 2 ), pos = ( - 137.33 , 298.0 ))# adding widget i.e button Rl.add_widget(btn) Rl.add_widget(btn1)# return the layout return Rl # run the App if __name__ = = "__main__" : MyApp().run()

输出如下：

文章图片
现在, 如果你希望按钮根据窗口进行调整pos_hint用来。
使用pos_hint的实现方法

# Sample Python application demonstrating the # working of RelativeLayout in Kivy # import modules import kivy # base Class of your App inherits from the App class. # app:always refers to the instance of your application from kivy.app import App # creates the button in kivy # if not imported shows the error from kivy.uix.button import Button # This layout allows you to set relative coordinates for children. from kivy.uix.relativelayout import RelativeLayout# To change the kivy default settings # we use this module config from kivy.config import Config # 0 being off 1 being on as in true / false # you can use 0 or 1 & & True or False Config. set ( 'graphics' , 'resizable' , True ) # creating the App class class Relative_Layout(App):def build( self ):# creating Relativelayout rl = RelativeLayout()# creating button # size of button is 20 % by hight and width of layout # position is bottom left i.e x = 0, y = 0 b1 = Button(size_hint = (. 2 , . 2 ), pos_hint = { 'x' : 0 , 'y' : 0 }, text = "B1" )# position is bottom right i.e right = 1, y = 0 b2 = Button(size_hint = (. 2 , . 2 ), pos_hint = { 'right' : 1 , 'y' : 0 }, text = "B2" )b3 = Button(size_hint = (. 2 , . 2 ), pos_hint = { 'center_x' :. 5 , 'center_y' :. 5 }, text = "B3" )b4 = Button(size_hint = (. 2 , . 2 ), pos_hint = { 'x' : 0 , 'top' : 1 }, text = "B4" )b5 = Button(size_hint = (. 2 , . 2 ), pos_hint = { 'right' : 1 , 'top' : 1 }, text = "B5" )# adding button to widget rl.add_widget(b1) rl.add_widget(b2) rl.add_widget(b3) rl.add_widget(b4) rl.add_widget(b5)# returning widget return rl # run the App if __name__= = "__main__" : Relative_Layout().run()

输出如下：