Waypoints 计数器递增（然后递减）并且在立即查看 div 时不执行脚本

Question

我有一个数字自动收报机。出于演示目的，这是 how the counter is meant to work。它计数然后停止。

现在，我正在尝试让代码脚本在 #ticker 出现时执行。为此，我使用 waypoints。但是，我遇到了以下问题：

#ticker 出现后，脚本不会立即执行。事实上，我必须滚动过去，然后当我向上滚动时，它才开始计数。
计数器正在向上计数，到达结束数然后向下计数？我只是希望它计数并停止在结束数字加上字符串（在本例中为 16,000+）。

为什么会这样？

演示：

$(document).ready(function() {

  $('#ticker').waypoint(function() {
    $('.count').each(function() {
      const initial = $(this).text()
      const format = formatter(initial)
      $(this).prop('Counter', 0).animate({
        Counter: format.value
      }, {
        duration: 3000,
        easing: 'swing',
        step: function(now) {
          $(this).text(format.revert(Math.ceil(now)));
        }
      });
    });
  });

})

function formatter(str) {
  // const delimeter = '-'
  const char = 'x'
  const template = str.replace(/\d/g, char)
  const value = str.replace(/\D/g, '')

  function revert(val) {
    // need better solution
    const valStr = val.toString()
    let result = ''
    let index = 0
    for (let i = 0; i < template.length; i++) {
      const holder = template[i]
      if (holder === char) {
        result += valStr.slice(index, index + 1)
        index++
      } else {
        result += holder
      }
    }
    return result
  }
  return {
    template: template,
    value: value,
    revert: revert
  }
}

.gap{
  background: lightgrey;
  height: 600px;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/waypoints/4.0.1/jquery.waypoints.min.js"></script>

<div class="gap"></div>
<div id="ticker">
  <span class="count counter">16,000+</span>
</div>
<div class="gap"></div>

Answer 1

Waypoint 插件有一个选项 offset，它决定了应该在哪个位置触发处理程序，默认情况下是 0。这意味着您的处理程序只会在您的元素到达浏览器的顶部边缘时触发，并且每次您的元素到达浏览器的顶部边缘时都会触发。

这就是您的情况，您只需将偏移量传递给 Waypoint，它就会被修复。

$(document).ready(function() {
  $('#ticker').waypoint({
    handler: function() {
      $('.count').each(function() {
        const initial = $(this).text()
        const format = formatter(initial)
        $(this).prop('Counter', 0).animate({
          Counter: format.value
        }, {
          duration: 3000,
          easing: 'swing',
          step: function(now) {
            $(this).text(format.revert(Math.ceil(now)));
          }
        });
      });
    },
    offset: '100%'
  });
})

function formatter(str) {
  // const delimeter = '-'
  const char = 'x'
  const template = str.replace(/\d/g, char)
  const value = str.replace(/\D/g, '')

  function revert(val) {
    // need better solution
    const valStr = val.toString()
    let result = ''
    let index = 0
    for (let i = 0; i < template.length; i++) {
      const holder = template[i]
      if (holder === char) {
        result += valStr.slice(index, index + 1)
        index++
      } else {
        result += holder
      }
    }
    return result
  }
  return {
    template: template,
    value: value,
    revert: revert
  }
}

.gap{
  background: lightgrey;
  height: 600px;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/waypoints/4.0.1/jquery.waypoints.min.js"></script>

<div class="gap"></div>
<div id="ticker">
  <span class="count counter">16,000+</span>
</div>
<div class="gap"></div>

Waypoints 计数器递增（然后递减）并且在立即查看 div 时不执行脚本

Waypoints counter counts up (then down) and doesn't execute script when div is in immediate view

javascript

jquery

jquery-waypoints

waypoint