'''Tkinter event (3 )'''
'''11. Two events are bound to one control simultaneously '''
#-*-Coding: cp936 -*-
# BIND: Events and processing functions
# Bind two events to the same component
# Bind two events to the root user
From tkinter import *
Root = TK ()
# Key event processing functions
Def printevent (event ):
Print '<key>', event. keycode
# Return event processing functions
Def printreturn (event ):
Print '<return>', event. keycode
Root. BIND ('<key>', printevent)
Root. BIND ('<return>', printreturn)
Root. mainloop ()
# Printevent processes keys except return.
# When the key is return, printreturn is used to handle the event, that is, the event with the "nearest.
'''12. bind an event to an instance. '''
# BIND: event handler function bound to the instance
#-*-Coding: cp936 -*-
From tkinter import *
Root = TK ()
# Key event processing functions
Def printevent (event ):
Print '<key>', event. keycode
# Return event processing functions
Def printreturn (event ):
Print '<return>', event. keycode
# Use Bt1 to add an event handler.
Bt1 = button (root, text = 'instance event ')
Bt1.bind ('<key>', printevent)
Bt1.focus _ set ()
Bt1.grid ()
Root. mainloop ()
# When the key is pressed, the program calls the printevent once.
'''13. Event-level audio transfer '''
#-*-Coding: cp936 -*-
# BIND: bind instance and toplevel
# Bind_class: bind a class Handler
# Bind_all: bind all events of the application
# "Transfer" between event levels"
From tkinter import *
Root = TK ()
# Key event processing functions
Def printevent (event ):
Print '<instance>', event. keycode
# Return event processing functions
Def printtoplevel (event ):
Print '<toplevel>', event. keycode
Def printclass (event ):
Print '<bind_class>', event. keycode
Def printappall (event ):
Print '<bind_all>', event. keycode
# Binding to printevent at the instance level
Bt1 = button (root, text = 'instance event ')
Bt1.bind ('<return>', printevent)
# Bind the toplevel of Bt1 to printtoplevel
Bt1.winfo _ toplevel (). BIND ('<return>', printtoplevel)
# Bind the event printclass at the class level
Root. bind_class ('click', '<return>', printclass)
# Bind printappall at application all level
Bt1.bind _ all ('<return>', printappall)
# Focus on Bt1 and press Enter. Four output prints are displayed.
Bt1.focus _ set ()
Bt1.grid ()
Root. mainloop ()
# Output result:
# <Instance> 13
# <Bind_class> 13
# <Toplevel> 13
# <Bind_all> 13
# Return: "pass" to the high level. The call order is instance/class/toplevel/All.
'''14. Consequences of using bind_class '''
#-*-Coding: cp936 -*-
# Bind_class: bind the event handler function of the entire class, which will affect all instances of this class.
From tkinter import *
Root = TK ()
Def printclass (event ):
Print '<bind_class>', event. keycode
# Changing the event binding of the button class
Root. bind_class ('click', '<return>', printclass)
# Create two buttons
Bt1 = button (root, text = 'a button ')
Bt2 = button (root, text = 'another click ')
Bt1.focus _ set ()
Bt1.grid ()
Bt2.grid ()
Root. mainloop ()
# Press enter and Bt1 print the result
# Switch the tab to bt2, and press enter to print the result, that is, all buttons respond to the return event.
'''15. Use protocal to bind '''
#-*-Coding: cp936 -*-
# Protocol: interacts with WM and binds event handlers.
From tkinter import *
Root = TK ()
Def printprotocol ():
Print 'wm _ delete_window'
Root. Destroy ()
# Use protocol to bind wm_delete_window to printprotocol
Root. Protocol ('wm _ delete_window ', printprotocol)
Root. mainloop ()
# Print 'wm _ delete_window 'when the program exits'
