循环播放，直到按下键并重复 [英] loop until key is pressed and repeat

问题描述

我试图在按下一个键时循环打印，并在按下另一个键时停止打印.

Im trying to loop a print when a key is pressed and stop when another key is pressed.

我也不想退出该程序，它必须继续侦听密钥.

Also I dont want to exit the program, it must continue listening for a key.

问题:但是我得到的是一个无限循环，因为当循环为True时，它无法监听另一个键！

from pynput import keyboard
    
def on_press(key):
    if key == keyboard.Key.f9:
        while True:
            print("loading")
    if key == keyboard.Key.f10:
        # Stop listener
        return False

# Collect events until released
with keyboard.Listener(on_press=on_press) as listener:
    listener.join()

我正在使用Pynput，请在此处查看文档

编辑

我确实解释了错误的一部分，我想在按下某个特定键 WAS 时进行循环.

I did explained wrong one part, I wanted to do a loop when a certain key WAS pressed.

推荐答案

您不能在 on_press (或任何长期运行的函数)中运行/>因为它阻止了 Listener .您必须在单独的 thread 中运行它.

You can't run while True (or any long-running function) inside on_press
because it blocks Listener. You have to run it in separated thread.

您需要 on_press 来创建和启动 thread .
然后 on_release 停止 thread .
它需要全局变量.IE.为此运行.

You need on_press to create and start thread.
And on_release to stop thread.
It needs global variable. ie. running for this.

我仅使用 datetime 来查看它是否显示新行.

I use datetime only to see if it displays new line or not.

from pynput import keyboard
import threading
import datetime

# --- functions ---

def loading():
    while running:
         print("loading", datetime.datetime.now()) #, end='\r')
    
def on_press(key):
    global running  # inform function to assign (`=`) to external/global `running` instead of creating local `running`

    if key == keyboard.Key.f9:
        running = True
        # create thread with function `loading`
        t = threading.Thread(target=loading)
        # start thread
        t.start()
        
    if key == keyboard.Key.f10:
        # stop listener
        return False

def on_release(key):
    global running  # inform function to assign (`=`) to external/global `running` instead of creating local `running`
    
    if key == keyboard.Key.f9:
        # to stop loop in thread
        running = False
        
#--- main ---

with keyboard.Listener(on_press=on_press, on_release=on_release) as listener:
    listener.join()

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