如何读取 Python Num-Lock Keypress Toggle 事件？

Question

对于一个项目，我正在制作一个完全由数字键盘控制的程序。很多依赖于数字键盘上的按钮能够被检测为是否被按住；我会在按下时将布尔值设置为真，在释放时将其设置为假。有了这些限制，我遇到了一个问题：每次按下 Num-Lock 键都会在向上和向下之间切换，释放时什么也没有。使用我用于其他键的相同系统，按一次键将使其变为真，再按一次将使其再次变为假，而不是按下它使其变为真并释放它使其再次变为假。

基本上，我怎样才能让小键盘 Num-Lock 键在按下和释放时触发某些东西，而不是在每次按下时切换？

目标操作系统：Windows 和 Linux (Raspberry Pi)
Python 3.x

我得到的输入与树莓派上的 Python 游戏相同，使用 event.type 和 event.key 等。

Answer 1

已经集成在Tkinter 中的事件处理程序可能会对您有很大帮助：

一个事件具有以下属性：

#       <event>.char        on-{ <KeyPress> | <KeyRelease> }
#              .keysym      on-{ <KeyPress> | <KeyRelease> }
#              .keysym_num  on-{ <KeyPress> | <KeyRelease> }
#              .height      on-{ <Configure> }
#              .width       on-{ <Configure> }
#              .num         on-{ <Mouse-1>  | <Mouse-2> | ... } ? 4,5 == <MouseWheel>
#              .serial      <-- system-assigned Integer
#              .time        <-- system-assigned Integer ( .inc each msec )
#              .widget      <-- system-assigned <widget>-instance
#              .x           <-- system-assigned <Event>-in-<widget>-mouse-location.x
#              .y           <-- system-assigned <Event>-in-<widget>-mouse-location.y
#              .x_root      <-- system-assigned <Event>-on-<Screen>-mouse-location.x
#              .y_root      <-- system-assigned <Event>-on-<Screen>-mouse-location.y

这个模型演示可以向您展示机制：

    #---------------------------------------------------------------# EVENT HANDLER DEMO:
    #       from Tkinter import *                                   # import Tkinter as tk
            root = Tk()                                             # root = tk.Tk()
            root.lift()    
            #-------------------------------------------------------                                                    
            >>> def aMouseEnterHANDLER( anEvent ):
            ...      print "<Enter>-event: ", anEvent.serial, anEvent.time, anEvent.x, anEvent.y, str( anEvent.widget )
            ...      print 
            ...
            >>> def KeyHANDLER( anEvent ):
            ...      print "<Key>-event: ", anEvent.serial, anEvent.time, anEvent.char, anEvent.keysym, anEvent.keysym_num, str( anEvent.widget )
            ...
            >>> root.bind( "<Enter>", aMouseEnterHANDLER )
            '23852056EnterHandler'
            >>> root.bind( "<KeyPress>", KeyHANDLER )               # root-widget level .bind()
            '23852576KeyHandler'

            >>> root.mainloop()                                     # <-- after entering this, <KeyPress> started to work ----------------------

            <Key>-event:  904 590059546 s s 115 .
            <Enter>-event:  911 590065062 1 5 .
            <Enter>-event:  911 590065062 1 5 .12965248
            <Enter>-event:  915 590067703 4 1 .
            <Enter>-event:  915 590067703 4 1 .12965248
            <Key>-event:  918 590069062 s s 115 .
            <Key>-event:  920 590069906 s s 115 .
            <Key>-event:  922 590070390  Caps_Lock 65509 .
            <Key>-event:  924 590071687  Shift_L 65505 .            
            <Key>-event:  925 590072187  Shift_L 65505 .
            <Key>-event:  926 590072218  Shift_L 65505 .
            <Key>-event:  927 590072250  Shift_L 65505 .
            <Key>-event:  928 590072281  Shift_L 65505 .
            <Key>-event:  929 590072328  Shift_L 65505 .
            <Key>-event:  930 590072359  Shift_L 65505 .
            <Key>-event:  931 590072390  Shift_L 65505 .
            <Key>-event:  932 590072421  Shift_L 65505 .
            <Key>-event:  934 590072890 A A 65 .
            <Key>-event:  936 590073390 A A 65 .
            <Key>-event:  938 590073531 A A 65 .
            <Key>-event:  940 590073718 A A 65 .
            <Key>-event:  942 590074093  Shift_L 65505 .
            <Key>-event:  944 590074625  Shift_L 65505 .
            <Key>-event:  946 590074843  Shift_L 65505 .
            <Key>-event:  948 590075031  Shift_L 65505 .
            <Key>-event:  950 590075656  Shift_L 65505 .
            <Key>-event:  952 590076031  Caps_Lock 65509 .
            <Enter>-event:  956 590109296 0 1 .
            <Enter>-event:  956 590109296 0 1 .12965248
            <Enter>-event:  959 590109734 6 5 .12965248
            <Enter>-event:  962 590110078 9 9 .
            <Enter>-event:  962 590110078 9 9 .12965248
            <Enter>-event:  965 590110328 9 10 .12965248
            <Enter>-event:  968 590111781 40 19 .
            <Key>-event:  968 590113875  Up 65362 .
            <Key>-event:  970 590114781  Left 65361 .
            <Key>-event:  972 590116718 + plus 43 .
            <Key>-event:  974 590117656 - minus 45 .
            Return 65293 .976 590118343
            <Key>-event:  978 590120359 d d 100 .
            <Key>-event:  980 590123312     Tab 65289 .
            <Key>-event:  988 590124140     Tab 65289 .12965248
            <Key>-event:  988 590124140     Tab 65289 .12965248
            <Key>-event:  990 590125578     Tab 65289 .12965248
            <Key>-event:  990 590125578     Tab 65289 .12965248