Python使用.kv文件的Kivy中的微调器小部件 _Python.kv文件

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。

微调小部件：
要使用微调器, 你必须导入：

from kivy.uix.spinner import Spinner

Spinner是一个小部件, 提供了一种从一组中选择一个值的快速方法。在默认状态下, 微调器显示其当前选定的值。触摸微调器会显示一个下拉菜单, 其中包含所有其他可用值, 用户可以从中选择一个新值。
像组合框一样, 微调器对象可以具有多个值, 并且可以选择一个值。
回调可以附加到微调器对象上, 以接收有关从微调器对象选择值的通知。

Basic Approach:1) import kivy 2) import kivyApp 3) import spinner 4) import Floatlayout(according to need) 5) import window(optional) 6) Set minimum version(optional) 7) Create Layout class: define the clicked function in it 8) Create App class 9) create .kv file (name same as the app class): 1) create Spinner 2) create callback 3) And many more styling as needed 10) return Layout/widget/Class(according to requirement) 11) Run an instance of the class

下面是实现：
在下面的代码中, 我们创建了微调器, 并进行了大小调整和定位, 并将回调函数附加到值上。
.py文件：

# Sample spinner app in kivy using .kv file# 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 )# Program to Show how to create a switch # import kivy module 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# this restrict the kivy version i.e # below this kivy version you cannot # use the app or software kivy.require( '1.9.0' )# Spinner is a widget that provides a # quick way to select one value from a set. # like a dropdown list from kivy.uix.spinner import Spinner# module consists the floatlayout # to work with FloatLayout first # you have to import it from kivy.uix.floatlayout import FloatLayout# Here for providing colour to the background from kivy.core.window import Window# create LayoutClass class SampBoxLayout(FloatLayout): # For Spinner defining spinner clicked function def spinner_clicked( self , value): print ( "Language selected is " + value)# # Make an App by deriving from the App class class SampleApp(App): def build( self ):# Set the background color for the window Window.clearcolor = ( 0.555 , 0.261 , . 888 , 0.5 ) return SampBoxLayout()# create object for thje Appclass root = SampleApp() # run the class root.run()

.kv文件
代码：

# .kv file implementation of the .py file# Creating the Layout i.e root of the Layout class < SampBoxLayout> :# creating the spinner Spinner: # Assigning id id : spinner_id# Callback on_text: root.spinner_clicked(spinner_id.text)# initially text on spinner text: "Python"# total values on spinner values: [ "Python" , "Java" , "C++" , "C" , "C#" , "PHP" ]# declaring size of the spinner # and the position of it size_hint: None , None size: 200 , 50 pos_hint:{ 'center_x' :. 5 , 'top' : 1 }

输出如下：
图片1