web前端使用原生js实现图片滑轮滚动放大缩小

 <img id="bigimg" @mousewheel="zoomimg($event)" style="border:5px solid #fff;" src="" />

 // 缩放图片
    zoomimg(event) {
      var delta = 0;
      if (!event) event = window.event;
      if (event.wheelDelta) {
        delta = event.wheelDelta / 120;
        if (window.opera) delta = -delta;
      } else if (event.detail) {
        delta = -event.detail / 3;
      }
      var img = document.getElementById('bigimg')
      if (delta > 0) {
        var width = img.width;
        img.width = width * 1.1;
      } else if (delta < 0) {
        var width = img.width;
        if (width > 400) {
          img.width = width * 0.9;
        }
      }
    },