頁面刷新后如何繼續計時？

Question

目前，我的代碼中有這個JavaScript

 function startTimer(duration, display) { var timer = duration, minutes, seconds; setInterval(function() { minutes = parseInt(timer / 60, 10); seconds = parseInt(timer % 60, 10); minutes = minutes < 10 ? "0" + minutes : minutes; seconds = seconds < 10 ? "0" + seconds : seconds; display.textContent = minutes + ":" + seconds; if (--timer < 0) { timer = 0; } }, 1000); } window.onload = function() { var fiveMinutes = 60 * 0.18, display = document.querySelector('#time'); startTimer(fiveMinutes, display); //`enter code here` }; 

 <div id="time"></div> 

刷新時如何保持計時器運行？ 使用Cookie是唯一的方法嗎？

Answer 1

我認為，如果您在服務器端沒有數據庫之類的東西和/或用戶未登錄，那么cookie是最好的選擇：

這可能有助於您入門，定義設置並獲取每個Cookie函數

組

 function setCookie(cname, cvalue, exdays) {
  var d = new Date();
  d.setTime(d.getTime() + (exdays*24*60*60*1000));
  var expires = "expires="+d.toUTCString();
  document.cookie = cname + "=" + cvalue + "; " + expires;
 } 

得到

function getCookie(cname) {
 var name = cname + "=";
 var ca = document.cookie.split(';');
 for(var i=0; i<ca.length; i++) {
    var c = ca[i];
    while (c.charAt(0)==' ') c = c.substring(1);
    if (c.indexOf(name) == 0) return c.substring(name.length,c.length);
 }
 return "";
} 

在文檔中的某個位置（也許在計時器中），將Cookie設置為：

setCookie("minutes", minutes.toString(), 1);
setCookie("seconds", seconds.toString(), 1);

然后在加載事件中的某處，通過get函數設置變量，如下所示：

minutes = getCookie("minutes");
seconds = getCookie("seconds");

在此處閱讀更多信息http://www.w3schools.com/js/js_cookies.asp

Answer 2

那只是關於如何制作cookie的指針，這是工作代碼。 在這里查看小提琴： https : //jsfiddle.net/edencorbin/hht4yqka/1/您需要調整計時器，我將其設置為10:00。

  <script>
  var minutes = 0;
  var seconds = 0;
  function startTimer(duration, display) {
    var timer = duration,
        minutes, seconds;
    setInterval(function() {
      minutes = parseInt(timer / 60, 10);
      seconds = parseInt(timer % 60, 10);

      minutes = minutes < 10 ? "0" + minutes : minutes;
      seconds = seconds < 10 ? "0" + seconds : seconds;

      display.textContent = minutes + ":" + seconds;

      setCookie("minutes", minutes.toString(), 1);
      setCookie("seconds", seconds.toString(), 1);

      if (--timer < 0) {
        timer = 0;
      }
    }, 1000);
  }


  window.onload = function() {
     var minutes_data = getCookie("minutes");
     var seconds_data = getCookie("seconds");
     var timer_amount = (60*10); //default
      if (!minutes_data || !seconds_data){
        //no cookie found use default
      }
      else{
        timer_amount = parseInt(minutes_data*60)+parseInt(seconds_data)
      }

    var fiveMinutes = timer_amount,
        display = document.querySelector('#time');
    startTimer(fiveMinutes, display); //`enter code here`
  };

   function setCookie(cname, cvalue, exdays) {
    var d = new Date();
    d.setTime(d.getTime() + (exdays*24*60*60*1000));
    var expires = "expires="+d.toUTCString();
    document.cookie = cname + "=" + cvalue + "; " + expires;
   } 

   function getCookie(cname) {
   var name = cname + "=";
   var ca = document.cookie.split(';');
   for(var i=0; i<ca.length; i++) {
      var c = ca[i];
      while (c.charAt(0)==' ') c = c.substring(1);
      if (c.indexOf(name) == 0) return c.substring(name.length,c.length);
   }
   return "";
  } 

  </script>

  <div id="time"></div>