考试倒计时jquery+cookie（防止刷新）

曾经终败给现在 2022-08-09 11:54 184阅读 0赞

在原贴的基础上改进了一下。基于jquery+cookie实现在线考试倒计时，关闭浏览器后重新打开后依然可以计时。一下代码在本地测试，由于chrome浏览器只支持web的cookie。在实际中倒计时的总时长应从后台获取。

<body>
    	<script type="text/javascript">
    	$(function() {
          var _minute = parseInt("1");//"1" 倒计时 多长时间，分钟为单位
          var _expiresHours = _minute * 60 * 1000;
             
          if(!hasSetCookie()){
        	//xxxx是cookie的标示,以下均是
            addCookie("xxxx", _expiresHours, _expiresHours);
          } 
          settime($("#remainTime")); 
        });
        function hasSetCookie(){
          var strCookie = document.cookie;
          var arrCookie = strCookie.split("; ");
          for (var i = 0; i < arrCookie.length; i++) {
            var arr = arrCookie[i].split("=");
            if (arr[0] == "xxxx") {
              return true;
            }
          }
          return false;
        }
        //开始倒计时
        function settime(remainTime) {
          var _time = getCookieValue("871d31bacfd4451484c5f70f8860c2a9");
          var _countdown = parseInt(getCookieValue("xxxx")) / 1000;
            
          if (_countdown == -1) {
            alert("考试时间到！");
            endExam();
          } else {
            var _second = _countdown % 60;
            var _minute = parseInt(_countdown / 60) % 60;
            var _hour = parseInt(parseInt(_countdown / 60) / 60);
      
            if (_hour < 10)
              _hour = "0" + _hour.toString();
            if (_second < 10)
              _second = "0" + _second.toString();
            if (_minute < 10)
              _minute = "0" + _minute.toString();
      
            remainTime.html(_hour + ":" + _minute + ":" + _second);
            _countdown--;
            editCookie("xxxx", _countdown * 1000, _countdown * 1000);
          }
          //每1000毫秒执行一次
          setTimeout(function() {
            settime(remainTime);
          }, 1000);
        }
      
        //时添加cookie
        function addCookie(name, value, expiresHours) {
          var cookieString = name + "=" + escape(value); //escape() 函数可对字符串进行编码，这样就可以在所有的计算机上读取该字符串。
          //判断是否设置过期时间,0代表关闭浏览器时失效
          if (expiresHours > 0) {
            var date = new Date();
            date.setTime(date.getTime() + expiresHours * 1000);
            cookieString = cookieString + ";expires=" + date.toUTCString();
          }
          document.cookie = cookieString;
        }
      
        //修改cookie的值
        function editCookie(name, value, expiresHours) {
          var cookieString = name + "=" + escape(value);
          if (expiresHours > 0) {
            var date = new Date();
            date.setTime(date.getTime() + expiresHours * 1000); //单位是毫秒
            cookieString = cookieString + ";expires=" + date.toGMTString();
          }
          document.cookie = cookieString;
        }
      
        //根据名字获取cookie的值
        function getCookieValue(name) {
          var strCookie = document.cookie;
          var arrCookie = strCookie.split(";");
          for (var i = 0; i < arrCookie.length; i++) {
            var arr = arrCookie[i].split("=");
            if (arr[0] == name) {
              return unescape(arr[1]);
              break;
            } else {
              continue;
            }
          }
        }
        
        </script>	
    	<span id="remainTime"></span>
    </body>