在javascript中长按按钮计算秒数

Question

我想使用javascript计算一次按下按钮（长按）的秒数，是否有任何在长按按钮时触发的功能或事件？

Answer 1

mousedown fires when the mouse button is held, mouseup when it's released.

With the use of variables, you can determine when a button is being held down and when it isn't.

Answer 2

You need to mix mousedown and mouseup events in order to achieve what you want.

Something like this:

 var timer = 0, timerInterval, button = document.getElementById("button"); button.addEventListener("mousedown", function() { timerInterval = setInterval(function(){ timer += 1; document.getElementById("timer").innerText = timer; }, 1000); }); button.addEventListener("mouseup", function() { clearInterval(timerInterval); timer = 0; });

 <button id="button">Button</button> <div id="timer">0</div>