您可以在文档主体上附加一个单击或鼠标移动事件，以重置计时器。

有一个函数，你在定时间隔调用，检查定时器是否超过指定的时间(如1000毫秒)，并开始你的预加载。

下面是tvanfosson的想法的粗略jQuery实现:

$(document).ready(function(){

   idleTime = 0;

   //Increment the idle time counter every second.
   var idleInterval = setInterval(timerIncrement, 1000);
   
   function timerIncrement()
   {
     idleTime++;
     if (idleTime > 2)
     {
       doPreload();
     }
   }
   
   //Zero the idle timer on mouse movement.
   $(this).mousemove(function(e){
      idleTime = 0;
   });
   
   function doPreload()
   {
     //Preload images, etc.
   }
   
})

我已经测试了这段代码工作文件:

var timeout = null;
    var timee = '4000'; // default time for session time out.
    $(document).bind('click keyup mousemove', function(event) {

    if (timeout !== null) {
            clearTimeout(timeout);
        }
        timeout = setTimeout(function() {
              timeout = null;
            console.log('Document Idle since '+timee+' ms');
            alert("idle window");
        }, timee);
    });

根据equiman提供的输入:

class _Scheduler {
    timeoutIDs;

    constructor() {
        this.timeoutIDs = new Map();
    }

    addCallback = (callback, timeLapseMS, autoRemove) => {
        if (!this.timeoutIDs.has(timeLapseMS + callback)) {
            let timeoutID = setTimeout(callback, timeLapseMS);
            this.timeoutIDs.set(timeLapseMS + callback, timeoutID);
        }

        if (autoRemove !== false) {
            setTimeout(
                this.removeIdleTimeCallback, // Remove
                10000 + timeLapseMS, // 10 secs after
                callback, // the callback
                timeLapseMS, // is invoked.
            );
        }
    };

    removeCallback = (callback, timeLapseMS) => {
        let timeoutID = this.timeoutIDs.get(timeLapseMS + callback);
        if (timeoutID) {
            clearTimeout(timeoutID);
            this.timeoutIDs.delete(timeLapseMS + callback);
        }
    };
}

class _IdleTimeScheduler extends _Scheduler {
    events = [
        'load',
        'mousedown',
        'mousemove',
        'keydown',
        'keyup',
        'input',
        'scroll',
        'touchstart',
        'touchend',
        'touchcancel',
        'touchmove',
    ];
    callbacks;

    constructor() {
        super();
        this.events.forEach(name => {
            document.addEventListener(name, this.resetTimer, true);
        });

        this.callbacks = new Map();
    }

    addIdleTimeCallback = (callback, timeLapseMS) => {
        this.addCallback(callback, timeLapseMS, false);

        let callbacksArr = this.callbacks.get(timeLapseMS);
        if (!callbacksArr) {
            this.callbacks.set(timeLapseMS, [callback]);
        } else {
            if (!callbacksArr.includes(callback)) {
                callbacksArr.push(callback);
            }
        }
    };

    removeIdleTimeCallback = (callback, timeLapseMS) => {
        this.removeCallback(callback, timeLapseMS);

        let callbacksArr = this.callbacks.get(timeLapseMS);
        if (callbacksArr) {
            let index = callbacksArr.indexOf(callback);
            if (index !== -1) {
                callbacksArr.splice(index, 1);
            }
        }
    };

    resetTimer = () => {
        for (let [timeLapseMS, callbacksArr] of this.callbacks) {
            callbacksArr.forEach(callback => {
                // Clear the previous IDs
                let timeoutID = this.timeoutIDs.get(timeLapseMS + callback);
                clearTimeout(timeoutID);

                // Create new timeout IDs.
                timeoutID = setTimeout(callback, timeLapseMS);
                this.timeoutIDs.set(timeLapseMS + callback, timeoutID);
            });
        }
    };
}
export const Scheduler = new _Scheduler();
export const IdleTimeScheduler = new _IdleTimeScheduler();

我也遇到过同样的问题，但我找到了一个很好的解决方案。

我使用jquery。无所事事，我只需要做:

$(document).idle({
  onIdle: function(){
    alert('You did nothing for 5 seconds');
  },
  idle: 5000
})

参见JsFiddle演示。

(仅供参考:查看后端事件跟踪Leads browserload)

JavaScript没有办法告诉CPU的使用情况。这将打破运行在沙盒中的JavaScript。

除此之外，连接页面的onmouseover和onkeydown事件可能会工作。

你也可以在onload事件中使用setTimeout来调度延迟后调用的函数。

// Call aFunction after 1 second
window.setTimeout(aFunction, 1000);