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我昨天问过关于在浏览器关闭时保存计时器值，然后在用户打开它时再次开始计数。我发现使用 cookie 一定是一个很好的解决方案，所以我添加了 set 和 getcookie 函数，但我仍然无法获取我的计时器值。这可能很容易，但我看不出有什么问题，因为我在 javascript 中仍然太菜鸟。有人知道我在做什么错吗？谢谢你！！这是我到目前为止的代码：

<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"><head>
    <title>Test</title>
    <script type="text/javascript">
var sec = 0;
var min =  0;
var hr = 0;
var dias = 0;
var bool = true;
function stopwatch() {
        sec++;
        if (sec == 60) {
            sec = 0;
            min += 1;
        }

        if (min == 60) {
            min = 0;
            hr += 1;
        }

        if (hr == 24) {
            hr = 0;
            dias += 1;
        }

        totalTime = ((dias<=9) ? "0" + dias : dias) + "d, " + ((hr<=9) ? "0" + hr : hr) + " : " + ((min<=9) ? "0" + min : min) + " : " + ((sec<=9) ? "0" + sec : sec);
        document.getElementById("timer").innerHTML = totalTime;
        if (bool == true) {
        start = setTimeout("stopwatch()", 1000);
        }

    }

function setCookie(name, value, expires) {
document.cookie = name + "=" + escape(value) + "; path=/" + ((expires == null) ? "" : "; expires=" + expires.toGMTString());
}



function getCookie (name) {
    var cname = name + "=";               
    var dc = document.cookie;

    if (dc.length > 0) {              
        begin = dc.indexOf(cname);       
            if (begin != -1) {           
            begin += cname.length;       
            end = dc.indexOf(";", begin);
                if (end == -1) end = dc.length;
                return unescape(dc.substring(begin, end));
            } 
        }
    return null;
}


var exp = new Date();                                  
exp.setTime(exp.getTime() + (1000 * 60 * 60 * 24 * 30));

    </script>
</head>
<body onload="stopwatch()">
    <div id="timer" name="timer"> </div>
  <button onclick="bool = false"; > pause </button>
  <button onclick="bool = true;stopwatch();" > resume </button>

    <form>
      <input type="button" value="Set a Cookie" onClick="setCookie('myCookie',timer.value, exp)">
    </form>
<form>
<input type="button" value="Get Cookie Value" onClick="this.form.tf.value = getCookie('myCookie')">
<input type="text" name="tf" size="30">
</form>

 </body>
</html>
4

2 回答 2

1

cookie 值保存为“未定义”，因为您没有存储正确的值：timer.value

将其更改为totalTime它可以工作：

<input type="button" value="Set a Cookie" onClick="setCookie('myCookie',totalTime, exp)">

看到这个小提琴

于 2012-06-09T15:34:46.160 回答
1

@floorish说的问题timer.value不存在，因为timer它是一个 DIV 元素并且没有value属性。

因此，您需要更改timer.value为document.getElementById('timer').innerHTML并且会很好。

现场 jsFiddle 演示

编辑1：

如果您希望计时器开始计算它保存在 cookie 上的位置，您应该在页面加载时读取 cookie。我是这样设计的：

<!DOCTYPE html>
<html>
<head>
<title>Timer</title>
</head>
<body>
<div id="timer">&nbsp;</div>
<button id="switcher"></button>
<p><input type="button" id="setCookie" value="Set a Cookie"></p>
<p><input type="button" id="getCookie" value="Get Cookie Value"> <input type="text" id="lastTime" size="30"></p>
<script>
/**
 * Set cookie 
 * @param {string} name Name of cookie
 * @param {string} value Value of the cookie
 * @param {object} expires Date object of expire time
 */
function setCookie(name, value, expires) {
  document.cookie = name + "=" + escape(value) + "; path=/" + ((expires == null) ? "" : "; expires=" + expires.toGMTString());
}

/**
 * Get cookie 
 * @param {string} name Name of cookie
 * @return {?string}
 */
function getCookie(name) {
    var cname = name + "=";               
    var dc = document.cookie;

    if (dc.length > 0) {              
    begin = dc.indexOf(cname);       
      if (begin != -1) {           
      begin += cname.length;       
      end = dc.indexOf(";", begin);
        if (end == -1) end = dc.length;
        return unescape(dc.substring(begin, end));
      } 
    }
    return null;
}

var time;

/**
 * Format time and return formatted string
 * @param {number} time Time in seconds that will formatted
 * @return {string}
 */
function formatTime(time) {
  var days = parseInt(time / 86400, 10); // Calculate days from seconds and delete decimals.
  if (0 > days) {
    days = 0;
  }

  var hours = parseInt((time -  days * 86400) / 3600, 10); // Calculate hours from seconds and delete decimals.
  if (0 > hours) {
    hours = 0;
  }

  var mins = parseInt((time -  days * 86400 - hours * 3600) / 60, 10); // Calculate minutes from seconds and delete decimals.
  if (0 > mins) {
    mins = 0;
  }

  var seconds = parseInt(time - days * 86400 - hours * 3600 - mins * 60, 10); // Calculate remain seconds.

  // Array for the time display, the content is something like:
  //   array(3) {
  //     0: '01',
  //     1: '57',
  //     2: '31'
  //   }
  var displayHours = [
    ((hours <= 9) ? '0' + hours : hours),
    ((mins <= 9) ? '0' + mins : mins),
    ((seconds <= 9) ? '0' + seconds : seconds)
  ];

  // Return formatted days and the displayHours is joined with ' : ', then it like this:
  //   '00d, ' + '01 : 57 : 31'
  return ((days <= 9) ? '0' + days : days) + 'd, ' + displayHours.join(' : ');
}

/**
 * Append to the 'timer' DIV the formatted time
 */
function watch() {
  // Append to the 'timer' DIV a formatted time
  //   ++time equal time = time + 1
  document.getElementById('timer').innerHTML = formatTime(++time);
}

/**
 * @type {?object} Variable to handle the interval timer.
 */
var timer = null;

/**
 * Switch between 'pause' and 'resume' time
 */
var switcher = function () {
  if (timer) { // If timer is assigned and not null
    clearInterval(timer); // Clear the interval to stop
    timer = null; // Null the timer
    document.getElementById('switcher').innerHTML = 'Resume'; // Change the word of the button to 'Resume'.
  } else {
    timer = setInterval(watch, 1000); // Start the interval timer
    document.getElementById('switcher').innerHTML = 'Pause'; // Change the word of the button to 'Pause'.
  }
};

// Assign on click event to 'switcher' button
document.getElementById('switcher').onclick = switcher;

// Assign on click event to 'setCookie' button
document.getElementById('setCookie').onclick = function () {
  // New Date object for the expire time
  var exp = new Date();
  // Set the expire time
  exp.setTime(exp + 2592000000);
  // Set a 'time' cookie with the current timer time and expire time object.
  setCookie('time', time, exp);
};

// Asign on click event to 'getCookie' button
document.getElementById('getCookie').onclick = function () {
  document.getElementById('lastTime').value = formatTime(getCookie('time'));
};

// Function that will call when document loaded.
window.onload = function () {
  // Get the time saved into the cookie and turn it to number.
  var oldTime = parseInt(getCookie('time'), 10);
  if (0 < oldTime) { // If the time saved
    time = oldTime; // Set the current time to the saved time
  } else { // If not time saved
    time = 0; // Set the current time to zero.
  }

  // Start the timer
  switcher();
}
</script>
</body>
</html>

现场 jsFiddle 演示

于 2012-06-09T15:50:14.507 回答