Python在Kivy中添加图像小部件示例

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。

图像小部件：

图像小部件用于显示图像。要使用图像小部件, 你必须导入：

from kivy.uix.image import Image, AsyncImage

因为模块kivy.uix.image具有与图像相关的所有功能。

可以通过两种类型将图像加载到应用程序：

1)从系统：wimg = Image(source =’mylogo.png’)2)异步加载：要异步加载图像(例如, 从外部Web服务器), 请使用AsyncImage子类：aimg = AsyncImage(source =’http： //mywebsite.com/logo.png’)

注意：默认情况下, 图像居中并适合窗口小部件边界框。如果你不想这样做, 可以设置allow_stretch到True和keep_ratio为假。

Basic Approach to create multiple layout in one file: 1) import kivy 2) import kivyApp 3) import image 4) set minimum version(optional) 5) create App class 6) return Image/layout/widget 7) Run an instance of the class

以下是代码, 如何使用代码中的图像：

代码1：

来自系统的简单映像(必须位于保存.py文件的文件夹中)

# Program to explain how to add image in kivy # 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' ) # The Image widget is used to display an image # this module contain all features of images from kivy.uix.image import Image # creating the App class class MyApp(App): # defining build() def build( self ): # return image return Image(source = 'download.jpg' ) # run the App MyApp().run()

输出如下：

代码2：

我们如何从网络服务器(外部)添加AsyncImage

# Simple program to show how we add AsyncImage in kivy App # 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' ) # The Image widget is used to display an image # this module contains all features of images from kivy.uix.image import AsyncImage # creating the App class class MyApp(App): # defining build() def build( self ): # return image return AsyncImage(source = 'http://kivy.org/logos/kivy-logo-black-64.png' ) # run the App MyApp().run()

输出如下：

现在想到了一件事情, 如何更改图像的大小, 位置等, 以下代码也将对此进行说明：

代码3：

# Program to Show how to use images in kivy # 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' ) # The Image widget is used to display an image # this module contain all features of images from kivy.uix.image import Image # The Widget class is the base class required for creating Widgets from kivy.uix.widget import Widget # 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): # defining build() def build( self ): # loading image self .img = Image(source = 'download.jpg' ) # By default, the image is centered and fits # inside the widget bounding box. # If you don’t want that, # you can set allow_stretch to # True and keep_ratio to False. self .img.allow_stretch = True self .img.keep_ratio = False # Providing Size to the image # it varies from 0 to 1 self .img.size_hint_x = 1 self .img.size_hint_y = 1 # Position set self .img.pos = ( 200 , 100 ) # Opacity adjust the fadeness of the image if # 0 then it is complete black # 1 then original # it varies from 0 to 1 self .img.opacity = 1 # adding image to widget s = Widget() s.add_widget( self .img) # return widget return s # run the app MyApp().run()

输出如下：

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