【读书笔记】 通过原生javascript获取margin
The properties on the style
object are only the styles applied directly to the element (e.g., via a style
attribute or in code). So .style.marginTop
will only have something in it if you have something specifically assigned to that element (not assigned via a style sheet, etc.).
To get the current calculated style of the object, you use either the currentStyle
property (Microsoft) or the getComputedStyle
function (pretty much everyone else).
Example:
var p = document.getElementById("target");
var style = p.currentStyle || window.getComputedStyle(p);
display("Current marginTop: " + style.marginTop);
Fair warning: What you get back may not be in pixels. For instance, if I run the above on a p
element in IE9, I get back "1em"
.