In my aspx page, I use xmlhttp.response to update a part of this page. This update occurs in every 3 seconds using js function. But when my PC goes to sleep mode, this update doesn't happen. This is OK. But when PC wake up from sleep mode, I need to start update automatically without reload this page. How to do this?

In my aspx page, I use xmlhttp.response to update a part of this page. This update occurs in every 3 seconds using js function. But when my PC goes to sleep mode, this update doesn't happen. This is OK. But when PC wake up from sleep mode, I need to start update automatically without reload this page. How to do this?

• javascript
• html
• xmlhttprequest
• dom-events

Share Improve this question Follow edited Nov 12, 2020 at 10:16 Brian Tompsett - 汤莱恩 5,8937272 gold badges6161 silver badges133133 bronze badges asked Jan 1, 2013 at 17:45 ShahriarShahriar 13.8k1111 gold badges8282 silver badges9797 bronze badges 2

• Duplicate of stackoverflow./questions/4079115/… – broofa Commented Jan 2, 2013 at 21:30
• Does this answer your question? Can any desktop browsers detect when the puter resumes from sleep? – Brian Tompsett - 汤莱恩 Commented Nov 12, 2020 at 10:17

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1 Answer 1

Sorted by: Reset to default 6

You can detect disruptions in the JS timeline (e.g. laptop sleep, alert windows that block JS excecution, debugger statements that open the debugger) by paring change in wall time to expected timer delay. For example:

var SAMPLE_RATE = 3000; // 3 seconds
var lastSample = Date.now();
function sample() {
  if (Date.now() - lastSample >= SAMPLE_RATE * 2) {
    // Code here will only run if the timer is delayed by more 2X the sample rate
    // (e.g. if the laptop sleeps for more than 3-6 seconds)
  }
  lastSample = Date.now();
  setTimeout(sample, SAMPLE_RATE);
}

sample();