Kivy 入门教程/Hello World!
在 Kivy 中，您需要做的第一件事是让一个屏幕出现。当您在 PC 上工作时，也会打开一个命令屏幕。如果您运行任何打印函数（我喜欢这些用于调试），它们将出现在命令屏幕中（我假设是 Apple OS 的终端，但我没有一个可以玩）。
打开 Python IDLE，然后打开一个新窗口以创建一个可保存的程序，并将以下代码复制到其中
- 代码示例 0
- 让一个屏幕出现
#!/usr/bin/env python
from kivy.app import App #We need to import the bits of kivy we need as we need them as importing everything would slow the app down unnecessarily
from kivy.uix.widget import Widget #this is a thing that you want the App to display
class Lesson0(Widget): #this defines the instance of the widget.
pass # pass is used to keep the class valid but allow it not to contain anything - At the moment our widget is not defined.
class MyApp(App):
def build(self):
return Lesson0()
if __name__ == '__main__': #Documentation suggests that each program file should be called main.py but I think that only matters if you're creating the final App to go onto a phone or tablet we're a long way off from that yet
MyApp().run() #This must match the name of your App
您需要通过 kivy 批处理文件运行它，才能让它与 kivy 库一起运行。有一种方法可以解决这个问题，但它可能很混乱，而这种方法效果很好。您可以在 kivy 网站上找到关于如何设置它的完整说明 这里。它应该打开一个空的黑色屏幕。
现在我们想要在屏幕上显示我们的“Hello World！”文本。为此，我们需要使用一个 Label 来显示文本。
- 代码示例 1
- 显示“Hello World！”
#!/usr/bin/env python
from kivy.app import App #We need to import the bits of kivy we need as we need them as importing everything would slow the app down unnecessarily
from kivy.uix.widget import Widget #this is a thing that you want the App to display
from kivy.uix.label import Label #this will import the code for the label in which we want to display Hello World!
class Lesson1App(App):
def build(self):
lbl=Label(text='Hello World!') #lbl is a variable name being assigned the Label definition
return lbl #This must match the name of the Widget you want to appear on screen
if __name__ == '__main__': #Documentation suggests that each program file should be called main.py but I think that only matters if you're creating the final App to go onto a phone or tablet we're a long way off from that yet
Lesson1App().run() #This must match the name of your App