京东放大镜遮罩 

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

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    * {
      padding: 0px;
      margin: 0px;
    }

    .box {
      width: 400px;
      height: 400px;
      border: 1px solid;
      position: relative;
      cursor: move;
      float: left;
    }

    .box2 {
      width: 400px;
      height: 400px;
      border: 1px solid;
      float: left;
      background-image: url(./images/138a986c7a96f8ba.jpg);
      background-position-x: -400px;
      display: none;
    }

    .ye {
      width: 200px;
      height: 200px;
      background: rgba(230, 247, 3, 0.5);
      position: absolute;
      z-index: 1;
      display: none;
    }

    .box img {
      width: 100%;
      vertical-align: bottom;
    }
  </style>
</head>

<body>
  <div class="box" id="box">
    <div class="ye" id="ye"></div>
    <img src="./images/138a986c7a96f8ba.jpg" alt="">
  </div>
  <div class="box2" id="box2"></div>
  <script>
    var box = document.getElementById("box");
    var box2 = document.getElementById("box2");
    var ye = document.getElementById("ye");
    box.addEventListener("mouseover", function () {
      ye.style.display = "block"
      box2.style.display = "block"
    })
    box.addEventListener("mousemove", function (e) {
      var x = e.clientX - this.offsetLeft;
      var y = e.clientY - this.offsetTop;

      var a_left = x - (ye.offsetWidth / 2)
      console.log(a_left)
      if (a_left <= 0) {
        a_left = 0;
      } else if (a_left >= (box.offsetWidth - ye.offsetWidth)) {
        a_left = box.offsetWidth - ye.offsetWidth;
      }
      ye.style.left = a_left + "px"

      var a_top = y - (ye.offsetHeight / 2);
      if (a_top <= 0) {
        a_top = 0;
      } else if (a_top >= (box.offsetHeight - ye.offsetHeight)) {
        a_top = box.offsetHeight - ye.offsetHeight;
      }
      ye.style.top = a_top + "px";

      box2.style.backgroundPositionX = -(ye.offsetLeft * 2) + "px"
      box2.style.backgroundPositionY = -(ye.offsetTop * 2) + "px"
    })

    box.addEventListener("mouseout", function () {
      ye.style.display = "none"
      box2.style.display = "none"
    })


  </script>
</body>

</html>
posted @ 2021-06-06 14:04  fk11  阅读(36)  评论(0)    收藏  举报