JS实现容器模块左右拖动效果_javascript技巧

#box {
  /*margin: 0 auto;*/
  width: 1750px;
  border: 1px solid black;
  display: block;
  position: relative;
  left: 0;
  }

  #box>div {
  width: 250px;
  height: 50px;
  display: inline-block;
  text-align: center;
  float: left;
  }

  h1 {
  padding: 0;
  margin: 0;
  }

<div style="width: 1000px;overflow: hidden;margin: auto;position: relative;">
  <div id="box">
  <div style="background: lemonchiffon;">
   <h1>one</h1></div>
  <div style="background: lightblue;">
   <h1>tow</h1></div>
  <div style="background: gold;">
   <h1>three</h1></div>
  <div style="background: blue;">
   <h1>four</h1></div>
  <div style="background: orange;">
   <h1>five</h1></div>
  <div style="background: aqua;">
   <h1>six</h1></div>
  <div style="background: brown;">
   <h1>seveen</h1></div>
  </div>
  <h1>拖动上面的颜色模块</h1>
 <p>实际原理还是轮播图</p>
</div>

<div style="width: 1000px;overflow: hidden;margin: auto;position: relative;">

<script src="jquery-2.1.0.js" type="text/javascript" charset="utf-8"></script>
 <script type="text/javascript">
 let box = document.getElementById('box')
 $box = $('#box')
 let mouseState = false; //鼠标默认状态
 let startX = 0;
 let startY = 0;
 let moveDirection = 0 //鼠标拖动距离
 $boxLeft = parseInt($box.css('left'))//表示内容块被偏移的值
 //鼠标按下事件
 box.addEventListener('mousedown', function(e) {
  //更改鼠标状态
  //参数e为鼠标
  mouseState = true
  //获取鼠标坐标
  startX = e.clientX
  startY = e.clientY
  //鼠标拖动初始化
  moveDirection = 0
  $boxLeft = parseInt($box.css('left'))
 })
 //鼠标移动状态
 box.addEventListener('mousemove', function(e) {
  //判断鼠标是不是被按下中移动
  if(mouseState) {
  //判断是向左还是向右拖动鼠标
  moveDirection = e.clientX - startX
  //向右移动
  box.style.left = $boxLeft + moveDirection + 'px'
  }
 })
 //鼠标弹起事件
 box.addEventListener('mouseup', function(e) {
  mouseState = false
  if(moveDirection > 0) {
  //$boxLeft<0表示已经看到最左的模块，不能在向右拖拉
  $boxLeft = parseInt($box.css('left'))
  //取余，比如拖动了52px，实际内容块就250px，偏移余下的px就能看的完整的内容块
  $num = $boxLeft % 250
  if($boxLeft < 0) {
   $box.animate({
   left: $boxLeft - $num + 'px'
   }, 500, function() {
   console.log(parseInt($box.css('left')))
   })
  } else {
  //向右偏移，如果$boxLeft大于等于0的话 那就是还是第一个颜色模块，不允许被偏移
   $box.animate({
   left: 0 + 'px'
   }, 500, function() {})
  }
  } else if(moveDirection < 0) {
  //$boxLeft>-750表示已经看到最右边的模块，不能在向左拖拉
  $boxLeft = parseInt($box.css('left'))
  $num = 250 + $boxLeft % 250
  if($boxLeft > -750) {
   $box.animate({
   left: $boxLeft - $num + 'px'
   }, 500, function() {
   console.log(parseInt($box.css('left')))
   })
  }else{
  //向左偏移，如果$boxLeft小于等于-750px的话 那就是最后一个颜色模块，不允许被偏移
   $box.animate({
   left: -750 + 'px'
   }, 500, function() {})
  }
  }
 })
</script>