记录：高清放大镜的事项

最新推荐文章于 2022-01-08 21:39:09 发布

chengsi7955

最新推荐文章于 2022-01-08 21:39:09 发布

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原文链接：https://my.oschina.net/u/3848851/blog/1814953

版权

<!DOCTYPE html>
<html>
<head lang="en">
  <meta charset="UTF-8">
  <title>哈哈</title>
  <style>
    * {
      margin: 0;
      padding: 0;
    }

    .box {
      width: 350px;
      height: 350px;
      margin: 100px;
      border: 1px solid #ccc;
      position: relative;
    }

    .big {
      width: 400px;
      height: 400px;
      position: absolute;
      top: 0;
      left: 360px;
      border: 1px solid #ccc;
      overflow: hidden;
      display: none;
    }

    .mask {
      width: 175px;
      height: 175px;
      background: rgba(255, 255, 0, 0.4);
      position: absolute;
      top: 0px;
      left: 0px;
      cursor: move;
      display: none;
    }

    .small {
      position: relative;
    }
  </style>
</head>
<body>
<div class="box" id="box">
  <div class="small"><!--小层-->
    <img src="images/small.png" width="350" alt=""/>
    <div class="mask"></div><!--遮挡层-->
  </div><!--小图-->
  <div class="big"><!--大层-->
    <img src="images/big.jpg" width="800" alt=""/><!--大图-->
  </div><!--大图-->
</div>
<!--导入外部的js文件-->
<script src="common.js"></script>
<script>

  //获取需要的元素
  var box = my$("box");
  //获取小图的div
  var small = box.children[0];
  //遮挡层
  var mask = small.children[1];
  //获取大图的div
  var big = box.children[1];
  //获取大图
  var bigImg = big.children[0];

  //鼠标进入显示遮挡层和大图的div
  box.onmouseover = function () {
    mask.style.display = "block";
    big.style.display = "block";
  };
  //鼠标离开隐藏遮挡层和大图的div
  box.onmouseout = function () {
    mask.style.display = "none";
    big.style.display = "none";
  };

  //鼠标的移动事件---鼠标是在小层上移动
  small.onmousemove = function (e) {
    //鼠标此时的可视区域的横坐标和纵坐标
    //主要是设置鼠标在遮挡层的中间显示
    var x = e.clientX - mask.offsetWidth / 2;
    console.log(e.clientX);
    var y = e.clientY - mask.offsetHeight / 2;
    //主要是margin的100px的问题
    x = x - 100;
    y = y - 100;
    //横坐标的最小值
    x = x < 0 ? 0 : x;
    //纵坐标的最小值
    y = y < 0 ? 0 : y;
    //横坐标的最大值
    x = x > small.offsetWidth - mask.offsetWidth ? small.offsetWidth - mask.offsetWidth : x;
    //纵坐标的最大值
    y = y > small.offsetHeight - mask.offsetHeight ? small.offsetHeight - mask.offsetHeight : y;
    //为遮挡层的left和top赋值
    mask.style.left = x + "px";
    mask.style.top = y + "px";

    //遮挡层的移动距离/大图的移动距离=遮挡层的最大移动距离/大图的最大移动距离
    //大图的移动距离=遮挡层的移动距离*大图的最大移动距离/遮挡层的最大移动距离

    //大图的横向的最大移动距离
    var maxX = bigImg.offsetWidth - big.offsetWidth;

    //大图的纵向的最大移动距离
    //var maxY = bigImg.offsetHeight - big.offsetHeight;

    //大图的横向移动的坐标
    var bigImgMoveX = x * maxX / (small.offsetWidth - mask.offsetWidth);
    //大图的纵向移动的坐标
    var bigImgMoveY = y * maxX / (small.offsetWidth - mask.offsetWidth);

    //设置图片移动
    bigImg.style.marginLeft = -bigImgMoveX + "px";
    bigImg.style.marginTop = -bigImgMoveY + "px";

  };
</script>


</body>
</html>

转载于:https://my.oschina.net/u/3848851/blog/1814953