js之滚轮事件-滚动改变大小-CFANZ编程社区

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title></title>
  <script type="text/javascript">
    window.onload = function(){
      var ptS = document.getElementsByTagName('input');
      console.log(ptS)
      document.onclick = function(e){
        var ev = window.event || e;
        // console.log(ev.target.nodeName)
        if(ev.target.nodeName == 'INPUT'){
          ev.target.onmousewheel = function(e){
            var ev = window.event || e;
            if(ev.wheelDelta > 0){
              //向上 +1
              ev.target.value = parseInt(ev.target.value) + 1;
              //阻止默认行为
              return false;
            }else{
              //向下 -1
              ev.target.value = parseInt(ev.target.value) - 1;
              //阻止默认行为
              return false;
            }
          }
          //火狐兼容
          if(ev.target.addEventListener != undefined){
            ev.target.addEventListener('DOMMouseScroll',function(e){
              var ev = window.event || e;
              if(ev.detail < 0){
                //向上 +1
                ev.target.value = parseInt(ev.target.value) + 1;
                //阻止默认行为
                ev.preventDefault();
              }else{
                //向下 -1
                ev.target.value = parseInt(ev.target.value) - 1;
                //阻止默认行为
                ev.preventDefault();
              }
            })
          }


        }
      }

    }
  </script>
</head>
<body>
  <h2>鼠标选中某一个input，滚动滚轮改变数字大小</h2>
  <input type="text" name="" value="1" />
  <input type="text" name="" value="2" />
  <input type="text" name="" value="3" />
</body>
</html>