python-2.7 - Pygame 键被​​按下

Question

告诉 pygame 在按下某个键时运行某些东西的惯用方式是什么？使用 pygame.key.get_pressed()[pygame.K_p]==True 或 pygame.mouse.get_pressed()==(1,0,0) 似乎仅在键或按钮被击中时使用react。例如，是否应该使用 while 循环？

我运行下面的代码，只有在按下键/按钮时我才会在 shell 中打印:

def main():
done = True
while done:
    for i in pygame.event.get():
        if pygame.key.get_pressed()[pygame.K_a] == 1:
            print "Key a is being pressed..."
        elif i.type == KEYDOWN and i.key == pygame.K_q:
            done = 0
    pygame.display.update()
pygame.quit()
main()

Answer 1

事件 KEYDOWN 表示“按键状态从 UP 变为 DOWN”——它并不表示“按键一直被按下”

当您开始按下按键时 - 它会生成事件 KEYDOWN 并且 pygame.event.get() 返回非空列表 - 以及 for 循环可以执行if pygame.event.get()

当您按住按键时 - 它不会生成事件 KEYDOWN - 并且 pygame.event.get() 返回空列表 - 并且 for 循环不执行 if pygame.event.get()

你的代码应该是这样的

running = True
while running:
    # check events 
    for event in pygame.event.get():
        if event.type == KEYDOWN:
            if event.key == pygame.K_q:
               running = False

    # do it outside of `for event` loop
    # it is executed many times 
    if pygame.key.get_pressed()[pygame.K_a]: 
        print "Key is hold pressed..."

    pygame.display.update()

或者 - 当你只需要执行一次时

key_A_pressed = False

running = True
while running:
    # check events 
    for event in pygame.event.get():
        if event.type == KEYDOWN:
            if event.key == pygame.K_q:
               running = False

            elif event.key == pygame.K_a:
               key_A_pressed = True

               # it is executed only once
               print "Key A - start pressing"

        if event.type == KEYUP:
            if event.key == pygame.K_a:
               key_A_pressed = False

               # it is executed only once
               print "Key A - stop pressing"

    # do it only once - outside of `for event` loop
    # it is executed many times 
    #if pygame.key.get_pressed()[pygame.K_a]: 
    # or
    if key_A_pressed:
        print "Key A is held pressed..."

    pygame.display.update()