每次你想在一个类的方法中使用它的属性时，你需要在它的前面加上 self. 前缀:

Every time you want to use an attribute of a class inside one of its methods, you need to prefix it with self.:

self.item = self.can.create_image(80, 80, image=self.pic)
#           ^^^^^                               ^^^^^

否则，Python 会将名称视为函数的本地名称，并在找不到它们时引发异常.

Otherwise, Python will treat the names as being local to the function and will raise an exception when it fails to find them.

此外，您忘记在画布小部件上调用 grid:

Also, you forgot to call grid on your canvas widget:

self.can = Canvas(root, width=160, height=160, bg='white')
self.can.grid(...)

关于 Tkinter 的资源，您可以查看这些:

As for resources on Tkinter, you can check out these:

• http://www.tkdocs.com/tutorial/onepage.html
• http://effbot.org/tkinterbook/