最近在試python的key board event ( in ubuntu) ,code如下
---------------------------
...
...
while(True):
with keyboard.Events() as events:
try:
# Block at most 0.1 second
event = events.get(0.1)
if event is None:
if axnCode=="STOP" or axnCode=="":
continue
lastStopCount+=1
if lastStopCount>=2 :
lastStopCount=0
axnCode="STOP"
else:
print('Received event {}'.format(event))
if(event.key==keyboard.Key.esc):
break
lastStopCount=0
if(event.key==keyboard.Key.left ):
axnCode="LEFT"
if(event.key==keyboard.Key.right ):
axnCode="RIGHT"
if(event.key==keyboard.Key.down ):
axnCode="DOWN"
if(event.key==keyboard.Key.up ):
axnCode="UP"
except:
print("unknown exception")
---------------------------
鍵盤動作(上下左右)訊息是很正常地捕捉到,閒置也正常反應出來,
真的是「get key取碼 一時爽,一直get key一直爽」
不過....
剛開始跑是沒問題,不過....幾秒後卻出現這樣的錯誤訊息
--------------------------------
Traceback (most recent call last):
File "/usr/lib/python3.10/threading.py", line 1009, in _bootstrap_inner
self.run()
File "/home/....../.local/lib/python3.10/site-packages/pynput/_util/__init__.py", line 210, in run
self._run()
File "/home/....../.local/lib/python3.10/site-packages/pynput/keyboard/_xorg.py", line 545, in _run
super(Listener, self)._run()
File "/home/....../.local/lib/python3.10/site-packages/pynput/_util/xorg.py", line 383, in _run
self._display_record = Xlib.display.Display()
File "/home/....../.local/lib/python3.10/site-packages/Xlib/display.py", line 80, in __init__
self.display = _BaseDisplay(display)
File "/home/....../.local/lib/python3.10/site-packages/Xlib/display.py", line 62, in __init__
display.Display.__init__(*(self, ) + args, **keys)
File "/home/....../.local/lib/python3.10/site-packages/Xlib/protocol/display.py", line 129, in __init__
raise error.DisplayConnectionError(self.display_name, r.reason)
Xlib.error.DisplayConnectionError: Can't connect to display ":10.0": b'Maximum number of clients reached'
---------------------------------
真的是想不通,明明只是read key,跟Display有什麼關係啊...
是有關係,畢竟pynput是要連接到xwin(xserver), 才能接收事件.所以會有connect問題
這時,才萬別想去改「/etc/X11/xorg.conf」.問題不在那裡
(而且ubuntu 22.04 預設是沒有xorg.conf,想要用 Xorg -configure產生Xorg.conf很多程序要做....我放棄了,但也好在沒產出 & 修改xorg.conf,不然又被誤導,走不少冤枉路了)
「所以,要改用別的python module來read key 嗎?」
「不用,只要一個小小的步驟就解決了」
------Before----
while(True):
with keyboard.Events() as events:
try:
...
...
except:
....
-----After---
with keyboard.Events() as events:
while(True):
try:
...
...
except:
....
-----------------------------
是的,就這麼簡單,如同c#對於using(.....)資源總是放在迴圈外,
python的「with」也請儘量放在while/for 外面,否則資源來不及回收就又open新的,那一定會入不敷出的
