Question

我有一个Tkinter GUI应用程序，我需要输入文本。我不能假设应用程序将具有焦点，所以我实现了pyHook，keylogger风格。

当GUI窗口没有焦点时，文本输入工作正常，StringVar正确更新。当GUI窗口具有焦点并且我尝试输入文本时，整个事情都会崩溃。

即，如果我在启动程序后单击控制台窗口或其他任何内容，则文本输入有效。如果我尝试立即输入文本（GUI以焦点开始），或者我在任何时候重新聚焦窗口并输入文本，它就会崩溃。

发生了什么？

以下是一个最小的完整可验证示例，用于说明我的意思：

from Tkinter import *
import threading
import time

try:
    import pythoncom, pyHook
except ImportError:
    print 'The pythoncom or pyHook modules are not installed.'

# main gui box
class TestingGUI:
    def __init__(self, root):

        self.root = root
        self.root.title('TestingGUI')

        self.search = StringVar()
        self.searchbox = Label(root, textvariable=self.search) 
        self.searchbox.grid()

    def ButtonPress(self, scancode, ascii):
        self.search.set(ascii)

root = Tk()
TestingGUI = TestingGUI(root)

def keypressed(event):
    key = chr(event.Ascii)
    threading.Thread(target=TestingGUI.ButtonPress, args=(event.ScanCode,key)).start()
    return True

def startlogger():
    obj = pyHook.HookManager()
    obj.KeyDown = keypressed
    obj.HookKeyboard()
    pythoncom.PumpMessages()

# need this to run at the same time
logger = threading.Thread(target=startlogger)
# quits on main program exit
logger.daemon = True
logger.start()

# main gui loop
root.mainloop()

Answer 1

我修改了问题中给出的源代码（和另一个），以便pyHook 相关的回调函数将键盘事件相关数据发送给队列。可以查看GUI对象通知事件的方式不必要的复杂。试着打电话给root.event_generate keypressed似乎挂了。也是set方法呼叫时，threading.Event似乎会造成麻烦 keypressed。

调用keypressed的上下文可能就在后面麻烦。

from Tkinter import *
import threading

import pythoncom, pyHook

from multiprocessing import Pipe
import Queue
import functools

class TestingGUI:
    def __init__(self, root, queue, quitfun):
        self.root = root
        self.root.title('TestingGUI')
        self.queue = queue
        self.quitfun = quitfun

        self.button = Button(root, text="Withdraw", command=self.hide)
        self.button.grid()

        self.search = StringVar()
        self.searchbox = Label(root, textvariable=self.search)
        self.searchbox.grid()

        self.root.bind('<<pyHookKeyDown>>', self.on_pyhook)
        self.root.protocol("WM_DELETE_WINDOW", self.on_quit)

        self.hiding = False

    def hide(self):
        if not self.hiding:
            print 'hiding'
            self.root.withdraw()
            # instead of time.sleep + self.root.deiconify()
            self.root.after(2000, self.unhide)
            self.hiding = True

    def unhide(self):
        self.root.deiconify()
        self.hiding = False

    def on_quit(self):
        self.quitfun()
        self.root.destroy()

    def on_pyhook(self, event):
        if not queue.empty():
            scancode, ascii = queue.get()
            print scancode, ascii
            if scancode == 82:
                self.hide()

            self.search.set(ascii)

root = Tk()
pread, pwrite = Pipe(duplex=False)
queue = Queue.Queue()

def quitfun():
    pwrite.send('quit')

TestingGUI = TestingGUI(root, queue, quitfun)

def hook_loop(root, pipe):
    while 1:
        msg = pipe.recv()

        if type(msg) is str and msg == 'quit':
            print 'exiting hook_loop'
            break

        root.event_generate('<<pyHookKeyDown>>', when='tail')

# functools.partial puts arguments in this order
def keypressed(pipe, queue, event):
    queue.put((event.ScanCode, chr(event.Ascii)))
    pipe.send(1)
    return True

t = threading.Thread(target=hook_loop, args=(root, pread))
t.start()

hm = pyHook.HookManager()
hm.HookKeyboard()
hm.KeyDown = functools.partial(keypressed, pwrite, queue)

try:
    root.mainloop()
except KeyboardInterrupt:
    quit_event.set()

使用pyHook的Tkinter文本条目挂起GUI窗口

1 个答案: