TkInter keypress, keyrelease events

问题:

I understood that the Tk keypress and keyrelease events were supposed only to fire when the key was actually pressed or released?

However with the following simple code, if I hold down the "a" key I get a continual sequence of alternating keypress/keyrelease events.

Am I doing something wrong or is TkInter buggy? This is Python2.7 on Linux mint.

from Tkinter import * def keyup(e):     print 'up', e.char def keydown(e):     print 'down', e.char  root = Tk() frame = Frame(root, width=100, height=100) frame.bind("<KeyPress>", keydown) frame.bind("<KeyRelease>", keyup) frame.pack() frame.focus_set() root.mainloop() 

Output when pressing and holding "a":

down a up a down a up a down a up a down a up a etc... 

回答1:

Ok some more research found this helpful post which shows this is occuring because of X's autorepeat behaviour. You can disable this by using

os.system('xset r off') 

and then reset it using "on" at the end of your script. The problem is this is global behaviour - not just my script - which isn't great so I'm hoping someone can come up with a better way.

回答2:

Autorepeat behavior is system dependent. In Win7,

down a down a down a ... down a up a 

This is for less than a second.

回答3:

how about;

from Tkinter import *  wn = Tk() wn.title('KeyDetect')  m = 0  def down(e):     if m == 0:         print 'Down\n', e.char, '\n', e         global m         m = 1  def up(e):     if m == 1:         print 'Up\n', e.char, '\n', e         global m         m = 0  wn.bind('<KeyPress>', down) wn.bind('<KeyRelease>', up)  wn.mainloop() 

now it won't repeat.

文章来源: TkInter keypress, keyrelease events