How to stop “setInterval” [duplicate]

问题

This question already has answers here:

Stop setInterval call in JavaScript (12 answers)

Closed 4 years ago.

How do I stop and start setInterval?

Suppose I have a textarea. I want to stop setInterval on focus and restart setInterval on blur (with jQuery).

回答1:

You have to store the timer id of the interval when you start it, you will use this value later to stop it, using the clearInterval function:

$(function () {
  var timerId = 0;

  $('textarea').focus(function () {
    timerId = setInterval(function () {
      // interval function body
    }, 1000);
  });

  $('textarea').blur(function () {
    clearInterval(timerId);
  });

});

回答2:

This is based on CMS's answer. The question asked for the timer to be restarted on the blur and stopped on the focus, so I moved it around a little:

$(function () {
  var timerId = 0;

  $('textarea').focus(function () {
    clearInterval(timerId);
  });

  $('textarea').blur(function () {
    timerId = setInterval(function () {
     //some code here 
    }, 1000);
  });
});

回答3:

Store the return of setInterval in a variable, and use it later to clear the interval.

var timer = null;
$("textarea").blur(function(){
    timer = window.setInterval(function(){ ... whatever ... }, 2000);
}).focus(function(){
    if(timer){
       window.clearInterval(timer);
       timer = null
    }
});

回答4:

setInterval returns an id that you can use to cancel the interval with clearInterval()

来源：https://stackoverflow.com/questions/1831152/how-to-stop-setinterval