HTML DOM WheelEvent deltaY 属性

htmlweb developmentfront end technology更新于 2024/1/30 16:44:17

HTML DOM WheelEvent deltaY 属性返回一个有符号数，对应于用户是向上还是向下滚动。如果用户在任何其他方向滚动，此属性返回 0。

语法

以下是语法 −

返回有符号数

event.deltaY

示例

让我们看一个 HTML DOM WheelEvent deltaY 属性的示例 −

<!DOCTYPE html>
<html>
<head>
<title>HTML DOM WheelEvent deltaY</title>
<style>
   * {
      padding: 2px;
      margin:5px;
   }
   form {
      width:70%;
      margin: 0 auto;
      text-align: center;
   }
   input[type="button"] {
      border-radius: 10px;
   }
   #content {
      width: 80px;
      height: 80px;
      margin: 20px 0 0 50px;
      background-color: #dc3545;
      transition: all 2s ease-in-out;
   }
</style>
</head>
<body>
   <form>
      <fieldset>
         <legend>HTML-DOM-WheelEvent-deltaY</legend>
         <div id="content" onwheel="setControls(event)"></div>
         <input type="button" value="reset" onclick="resetCSS()">
         <div id="divDisplay">Scroll over div element</div>
      </fieldset>
   </form>
   <script>
   var playDiv = document.getElementById("content");
   var count = 40;
   function setControls(event) {
      var valX = event.deltaX;
      var valY = event.deltaY;
         if(valY>0){
            playDiv.style.transform = "scale(0.5)";
            playDiv.style.backgroundColor = "rgba(0, 188, 212, 0.47)";
            playDiv.style.borderRadius = "50%";
         }
         else if(valY<0){
            playDiv.style.transform = "scale(1.5)";
            playDiv.style.backgroundColor = "rgba(0, 188, 0, 0.47)";
            playDiv.style.borderRadius = "0px";
         }
         else if(valX>0){
            count+=40;
            playDiv.style.transform = "translateX("+count+"px)";
         }
         else{
            count-=40;
            playDiv.style.transform = "translateX("+count+"px)";
         }
      }
      function resetCSS(){
         count = 40;
         var st = "width: 80px;height: 80px;margin: 20px 0 0 50px;background-color:
         #dc3545;transition: all 2s ease-in-out;";
         playDiv.style = st;
      }
   </script>
</body>
</html>