getComputedStyle属性值

时间:2015-09-24 05:48:02

标签: javascript css3 getcomputedstyle

我试图报告我创建的椭圆div的边界半径的值,但是我返回了未定义的值。有谁能解释为什么?我犯了一个简单的错误,或者我的代码有问题吗?谢谢!

<!DOCSTYLE html>
<html>
<head>
    <title>CSS3</title>
    <style>
        #oval{
            width: 500px;
            height: 300px;
            background: black;
            border-bottom-left-radius: 50%;
            border-bottom-right-radius: 50%;
            border-top-left-radius: 50%;
            border-top-right-radius: 50%;
        }
    </style>
    <script>
        var myOval = document.getElementById('oval');
        var bRadBL = window.getComputedStyle(myOval).getPropertyValue("border-bottom-left-radius");
        var bRadBR = window.getComputedStyle(myOval).getPropertyValue("border-bottom-right-radius");
        var bRadTL = window.getComputedStyle(myOval).getPropertyValue("border-top-left-radius");
        var bRadTR = window.getComputedStyle(myOval).getPropertyValue("border-top-right-radius");
        var bRad = getComputedStyle(myOval).getPropertyValue("borderRadius");
        function compStyle(){
            alert("Top Left Radius: "+bRadTL+"\nBottom Left Radius: "+bRadBL+"\nTop Right Radius: "+bRadTR+"\nBottom Right Radius: "+bRadBR);
     }
    </script>
</head>
<body>
    <div id="oval"></div>
    <input type="button" value="click me" onClick="compStyle()"/>
</body>
</html>

编辑:我已尝试过两个&#34; border-bottom-left-radius&#34;和&#34; borderBottomLeftRadius&#34;结果相同。我应该使用哪一个?

1 个答案:

答案 0 :(得分:2)

在渲染元素之前运行脚本。在声明html元素id之后,将脚本块移动到正文的末尾:

#oval{
  width: 500px;
  height: 300px;
  background: black;;
  border-bottom-left-radius: 50%;
  border-bottom-right-radius: 50%;
  border-top-left-radius: 50%;
  border-top-right-radius: 50%;
}
<div id="oval"></div>
<input type="button" value="click me" onClick="compStyle()"/>

<script>
  var myOval = document.getElementById('oval');
  var bRadBL = window.getComputedStyle(myOval).getPropertyValue("border-bottom-left-radius");
  var bRadBR = window.getComputedStyle(myOval).getPropertyValue("border-bottom-right-radius");
  var bRadTL = window.getComputedStyle(myOval).getPropertyValue("border-top-left-radius");
  var bRadTR = window.getComputedStyle(myOval).getPropertyValue("border-top-right-radius");
  var bRad = getComputedStyle(myOval).getPropertyValue("borderRadius");
  function compStyle(){
    alert("Top Left Radius: "+bRadTL+"\nBottom Left Radius: "+bRadBL+"\nTop Right Radius: "+bRadTR+"\nBottom Right Radius: "+bRadBR);
  }
</script>