限制 JavaScript 中的函数范围滑块用例？

问题描述

在下面的脚本中，代码在有滑块时工作，但当页面上的滑块数量超过一个时，下一个滑块不起作用。

当页面上有多个滑块时，如何更改此脚本，使每个滑块“可拖动功能”单独工作且不重叠？

需要进行哪些更改才能使此代码“可拖动功能”为每个滑块单独工作？

如何使用“ querySelectorAll ”和“ forEach ”处理这个问题？

const slider = document.querySelector('.items');
let isDown = false;
let startX;
let scrollLeft;

slider.addEventListener('mousedown',(e) => {
  isDown = true;
  slider.classList.add('active');
  startX = e.pageX - slider.offsetLeft;
  scrollLeft = slider.scrollLeft;
});
slider.addEventListener('mouseleave',() => {
  isDown = false;
  slider.classList.remove('active');
});
slider.addEventListener('mouseup',() => {
  isDown = false;
  slider.classList.remove('active');
});
slider.addEventListener('mousemove',(e) => {
  if (!isDown) return;
  e.preventDefault();
  const x = e.pageX - slider.offsetLeft;
  const walk = (x - startX) * 3; //scroll-fast
  slider.scrollLeft = scrollLeft - walk;
});

.items,.items_1 {
  position: relative;
  width: 90%;
  background: green;
  overflow-x: scroll;
  overflow-y: hidden;
  white-space: nowrap;
  transition: all 0.2s;
  transform: scale(0.98);
  will-change: transform;
  user-select: none;
  cursor: pointer;

  margin: 2rem auto;
  border: 3px solid violet;

}

.item {
  display: inline-block;
  background: red;
  min-height: 50px;
  min-width: 150px;
  margin: .5rem;
}

<!DOCTYPE html>
<html lang="en">

<head>
  <title>slider</title>
  <link rel="stylesheet" href="./style.css">
</head>


<body>

  <div class="items">

    <div class="item"></div>
    <div class="item"></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>

  </div>


  <div class="items">

    <div class="item"></div>
    <div class="item"></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>

  </div>

  <div class="items">

    <div class="item"></div>
    <div class="item"></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>

  </div>


  <script src="./script.js"></script>

</body>

</html>

解决方法

如何使用“querySelectorAll”和“forEach”处理这个问题？

只需将声明状态变量并将事件处理程序附加到一个滑块的代码放入这样的循环中：

const sliders = document.querySelectorAll('.items');
for (const slider of sliders) {
  let isDown = false;
  let startX;
  let scrollLeft;

  slider.addEventListener('mousedown',(e) => {
    isDown = true;
    slider.classList.add('active');
    startX = e.pageX - slider.offsetLeft;
    scrollLeft = slider.scrollLeft;
  });
  slider.addEventListener('mouseleave',() => {
    isDown = false;
    slider.classList.remove('active');
  });
  slider.addEventListener('mouseup',() => {
    isDown = false;
    slider.classList.remove('active');
  });
  slider.addEventListener('mousemove',(e) => {
    if (!isDown) return;
    e.preventDefault();
    const x = e.pageX - slider.offsetLeft;
    const walk = (x - startX) * 3; //scroll-fast
    slider.scrollLeft = scrollLeft - walk;
  });
}

.items {
  position: relative;
  width: 90%;
  background: green;
  overflow-x: scroll;
  overflow-y: hidden;
  white-space: nowrap;
  transition: all 0.2s;
  transform: scale(0.98);
  will-change: transform;
  user-select: none;
  cursor: pointer;

  margin: 2rem auto;
  border: 3px solid violet;

}
.items.active {
  border-color: blue;
}

.item {
  display: inline-block;
  background: red;
  min-height: 50px;
  min-width: 150px;
  margin: .5rem;
}

<!DOCTYPE html>
<html lang="en">

<head>
  <title>slider</title>
  <link rel="stylesheet" href="./style.css">
</head>


<body>

  <div class="items">

    <div class="item"></div>
    <div class="item"></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>

  </div>


  <div class="items">

    <div class="item"></div>
    <div class="item"></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>

  </div>

  <div class="items">

    <div class="item"></div>
    <div class="item"></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>
    <div class="item "></div>

  </div>


  <script src="./script.js"></script>

</body>

</html>

我猜你的问题是这个问题。您所需要的只是将您的代码包装到一个函数中，并为每个滑块设置一个参数。

const slider1 = document.querySelector('.items1');
const slider2 = document.querySelector('.items2');
const slider3 = document.querySelector('.items3');
let isDown = false;
let startX;
let scrollLeft;

const sliderFunc = el => {
  el.addEventListener('mousedown',e => {
    isDown = true;
    el.classList.add('active');
    startX = e.pageX - el.offsetLeft;
    scrollLeft = el.scrollLeft;
  });
  el.addEventListener('mouseleave',() => {
    isDown = false;
    el.classList.remove('active');
  });
  el.addEventListener('mouseup',() => {
    isDown = false;
    el.classList.remove('active');
  });
  el.addEventListener('mousemove',e => {
    if (!isDown) return;
    e.preventDefault();
    const x = e.pageX - el.offsetLeft;
    const walk = (x - startX) * 3; //scroll-fast
    el.scrollLeft = scrollLeft - walk;
  });
};
sliderFunc(slider1);
sliderFunc(slider2);
sliderFunc(slider3);

.items1,.items2,.items3,.items_1 {
  position: relative;
  width: 90%;
  background: green;
  overflow-x: scroll;
  overflow-y: hidden;
  white-space: nowrap;
  transition: all 0.2s;
  transform: scale(0.98);
  will-change: transform;
  user-select: none;
  cursor: pointer;
  margin: 2rem auto;
  border: 3px solid violet;
}

.item {
  display: inline-block;
  background: red;
  min-height: 50px;
  min-width: 150px;
  margin: 0.5rem;
}

<div class="items1">
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
</div>

<div class="items2">
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
</div>

<div class="items3">
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
</div>

javascript restrict restriction

限制 JavaScript 中的函数范围滑块用例？

问题描述

解决方法

相关问答