js实现拖动盒子查看内容 内容拖动
一.分析实现过程
1.鼠标拖动的操作是，按下鼠标不松，拖动鼠标，就需要监听鼠标点击事件(onmousedown),鼠标拖动事件(onmousemove)
2.鼠标拖动事件的监听时机，是在按下鼠标之后监听的，所以鼠标拖动事件需要放在鼠标按下事件(onmousedown)中
3.获取鼠标点击的位置A在外层盒子中可视区域x轴位置(clientX)及x轴滚动条位置B(scrollLeft)
4.在外层盒子中鼠标点击盒子的位置拖动的时候获取可视区域x轴位置C减去一开始点击的位置A,之后用位置B减去，C减A的值，这就是最终盒子需要跟随鼠标所拖动的位置
5.鼠标抬起释放事件
二.实现代码
<style>.outBox{width:300px;height:200px;background: blanchedalmond; overflow: hidden;margin:20px auto;}.innerBox{width: 600px;height: 200px;cursor: grab;} </style> <body><div class="outBox"><div class="innerBox"><span>Lorem ipsum dolor sit amet consectetur adipisicing elit. Debitis nam id neque cupiditate a, nihil corporis aut officiis nesciunt, incidunt consequuntur accusamus, iusto architecto nemo? Aspernatur omnis soluta molestiae excepturi!</span><span>Lorem ipsum dolor sit amet consectetur adipisicing elit. Debitis nam id neque cupiditate a, nihil corporis aut officiis nesciunt, incidunt consequuntur accusamus, iusto architecto nemo? Aspernatur omnis soluta molestiae excepturi!</span><span>Lorem ipsum dolor sit amet consectetur adipisicing elit. Debitis nam id neque cupiditate a, nihil corporis aut officiis nesciunt, incidunt consequuntur accusamus, iusto architecto nemo? Aspernatur omnis soluta molestiae excepturi!</span><span>Lorem ipsum dolor sit amet consectetur adipisicing elit. Debitis nam id neque cupiditate a, nihil corporis aut officiis nesciunt, incidunt consequuntur accusamus, iusto architecto nemo? Aspernatur omnis soluta molestiae excepturi!</span><span>Lorem ipsum dolor sit amet consectetur adipisicing elit. Debitis nam id neque cupiditate a, nihil corporis aut officiis nesciunt, incidunt consequuntur accusamus, iusto architecto nemo? Aspernatur omnis soluta molestiae excepturi!</span></div></div><script>let wrapperBox= document.querySelector('.outBox')let innerBox=document.querySelector('.innerBox')wrapperBox.onmousedown=function(e){let startX=e.clientX;let originalScrollX=wrapperBox.scrollLeft;document.onmousemove=function(e){let subs=e.clientX-startX; wrapperBox.scrollLeft= originalScrollX-subs;}//鼠标抬起释放事件document.onmouseup=function(){document.onmousemove=document.onmouseup=null; }}</script> </body>