python开发_tkinter_获取文本框内容_给文本框添加键盘输入事件

 1 from tkinter import *
 2 
 3 __author__ = {'name' : 'Hongten',
 4               'mail' : 'hongtenzone@foxmail.com',
 5               'blog' : 'http://www.cnblogs.com/',
 6               'QQ': '648719819',
 7               'created' : '2013-09-11'}
 8 
 9 # This program  shows how to make a typein box shadow a program variable.
10 flag = True
11 class App(Frame):
12     def __init__(self, master=None):
13         Frame.__init__(self, master)
14         self.pack()
15 
16         self.entrythingy = Entry(self)
17         self.entrythingy.pack()
18 
19         self.button = Button(self, text="Uppercase The Entry",
20                              command=self.upper)
21         self.button.pack()
22 
23         # here we have the text in the entry widget tied to a variable.
24         # changes in the variable are echoed in the widget and vice versa.
25         # Very handy.
26         # there are other Variable types. See Tkinter.py for all
27         # the other variable types that can be shadowed
28         self.contents = StringVar()
29         self.contents.set("this is a variable")
30         self.entrythingy.config(textvariable=self.contents)
31 
32         # and here we get a callback when the user hits return. we could
33         # make the key that triggers the callback anything we wanted to.
34         # other typical options might be <Key-Tab> or <Key> (for anything)
35         self.entrythingy.bind('<Key-Return>', self.print_contents)
36 
37     def upper(self):
38         # notice here, we don't actually refer to the entry box.
39         # we just operate on the string variable and we
40         # because it's being looked at by the entry widget, changing
41         # the variable changes the entry widget display automatically.
42         # the strange get/set operators are clunky, true...
43         global flag
44         flag = not flag
45         if not flag:
46             str = self.contents.get().upper()
47             self.contents.set(str)
48         else:
49             str = self.contents.get().lower()
50             self.contents.set(str)
51         print('the contents is : ', self.contents.get())
52 
53     def print_contents(self, event):
54         print("hi. contents of entry is now ---->", self.contents.get())
55 
56 root = App()
57 root.master.title("Foo")
58 root.mainloop()