WhyCan Forum(哇酷开发者社区)

https://stackoverflow.com/questions/9451559/what-is-the-difference-between-clicked-and-pressed-in-qt

Pressed: event is generated when you push down the mouse button
Released: event is generated when you release the mouse button (which has been pressed down before)
Clicked: event is generated when a mouse button Pressed & Released.
With these functions you can create a snap-switch for example:

when you press the button, the light will switch off / the music starts / etc, when you release it, light switches back on / the music starts again etc.

按下：当您按下鼠标按钮时会生成事件
发布：当您释放鼠标按钮（以前已被按下）时会生成事件
点击：当鼠标按钮按下并释放时生成事件。
通过这些功能，您可以创建一个快照开关，例如：

当您按下按钮时，指示灯将关闭/音乐启动/ etc，当您释放它，灯开关重新开始/音乐再次启动等。