Question

单击按钮时，我试图增加/减少段落中的值。

$(document).ready(function() {
  var breakTime = 5;
  var section = 25;
  var start = "Start";
  var stop = "Stop";


  function Pomodoro(element, target) {
    this.element = element;
    this.target = target;
  };

  Pomodoro.prototype.incrementer = function incrementer() {
    // this takes care of break and section timers incrementing

    this.element.click(function() {
      breakTime++;
      var el = this.target;
      el.html(breakTime);
    });
  };
  // end

  Pomodoro.prototype.decrementer = function decrementer() {
    // this takes care of break and section timers incrementing

    breakerDec.element.click(function() {
      breakTime--;
      var el = breakerDec.target.html(breakTime);
    });
  };
  // end

  var breakerInc = new Pomodoro();
  var ele = $("#inner1");
  var tar = $("#par");

  breakerInc.element = ele;
  breakerInc.target = tar;

  breakerInc.incrementer.bind(breakerInc);
  //end

  var breakerDec = new Pomodoro();

  breakerDec.element = $("#inner2");
  breakerDec.target = $("#par");

  breakerDec.decrementer();

  var sectionInc = new Pomodoro($("#inner3"), $("#par2"));
  sectionInc.incrementer.bind(sectionInc);
});

当我点击按钮时，我没有得到任何结果。这是html：

<html lang="en">
  <head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>Pomodoro Timer</title><!-- End of Title -->
    <link rel="stylesheet" type="text/css" href="style.css">
  </head>
  <body>
    <div class="wrapper">
      <div class="top">
        <div class="div div-1"><p id="par" class="breaktime-1">5</p>
          <div  class="inner-div inner-1"><button id="inner1" type="button" class="btn">+</button></div>
          <div class="inner-div inner-2"><button id="inner2" type="button" class="btn">-</button></div>
        </div>
        <div class="div div-2"><p id="par2" class="breaktime">25</p>
          <div class="inner-div inner-1"><button id="inner3" type="button" class="btn">+</button></div>
          <div class="inner-div inner-2"><button id="inner4" type="button" class="btn">-</button></div>
        </div>
      </div>
      <div class="div div-3">
        <h3 class="heading">section</h3>
        <button type="button" class="btn-Start-Stop"></button
      </div>
      <div><p></p></div>
    </div>

    <script type="text/javascript" src="http://ajax.aspnetcdn.com/ajax/jQuery/jquery-2.1.4.js"></script> 
    <script type="text/javascript" src="main.js"></script>
  </body>
</html>

Answer 1

这是一个（精简版）解决方案，仅使用vanilla javascript：

function changeValue() {
var breaktime = this.parentNode.getElementsByClassName('breaktime')[0];
var val = breaktime.innerHTML;

if (this.className === 'increment') {
    val++;
}

else if (this.className === 'decrement') {
    val--;
}

breaktime.innerHTML = val;
}


function startStop() {
var values = [];
var breaktimes = document.getElementsByClassName('breaktime');

breaktimes[1].classList.toggle('decrementing');

if (breaktimes[1].classList.contains('decrementing') === true) {

        values[1] = parseInt(breaktimes[1].innerHTML);

        values[1]--;
        breaktimes[1].innerHTML = values[1];

    var decrementer = setInterval(function(){
        
        values[0] = parseInt(breaktimes[0].innerHTML);
        values[1] = parseInt(breaktimes[1].innerHTML);

        if (breaktimes[1].classList.contains('decrementing') !== true) {
            clearInterval(decrementer);
        }

        values[1]--;
        breaktimes[1].innerHTML = values[1];

        if (values[1] === values[0]) {
        window.alert('The counter has reached ' + values[1]);
        clearInterval(decrementer);
        }

    }, 1000);

}

}



var buttons = document.getElementsByTagName('button');
var startStopButton = buttons[(buttons.length -1)];

for (var i = 0; (i+1) < buttons.length; i++) {
buttons[i].addEventListener('click',changeValue,false);
}

startStopButton.addEventListener('click',startStop,false);

<section>

<div>
<p class="breaktime">5</p>
<button id="inner1" type="button" class="increment">+</button>
<button id="inner2" type="button" class="decrement">-</button>
</div>

<div>
<p class="breaktime">25</p>
<button id="inner3" type="button" class="increment">+</button>
<button id="inner4" type="button" class="decrement">-</button>
</div>

<div>
<h3>Section</h3>
<button type="button" class="btn-Start-Stop">Start / Stop</button>
</div>

<div>
<p></p>
</div>

</section>

Answer 2

如果您想使用构造函数实现逻辑，则可以在实例的初始化中绑定事件。

Here根据您的HTML重新编写代码。但是代码可以改进，因此Pomodoro实例不仅可以减少或增加，而且可以执行这两个功能。

此外，一些模板引擎可以让您轻松定义要添加到页面的增加/减少块的数量。

Javascript事件处理程序无法正常工作

2 个答案: