如何检查svg的填充不透明度与填充不透明度为0？

Question

Suppose I want to check the fill-opacity of a SVG element. I'd do this

elem.attr('fill-opacity');

This can give me back 0 if the element has no fill-opacity attribute or if the fill-opacity has been set to 0.

How do I distinguish between those two cases?

Answer 1

您不能简单地使用elem.hasAttribute吗？

Answer 2

If fill-opacity is not specified, attr() returns undefined .

 alert("fill-opacity (DOM) ="+document.getElementById("test").getAttribute("fill-opacity")); alert("fill-opacity (jQuery) ="+$("#test").attr("fill-opacity")); 

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <svg> <rect id="test" width="10" height="10"/> </svg>