关于jquery获取style特性值

因为jquery获取css属性时，获取的是计算后的属性
jquery.css()

function (elem, name, extra) {
    var ret, hooks;

    // Make sure that we're working with the right name
    name = jQuery.camelCase(name);
    hooks = jQuery.cssHooks[name];
    name = jQuery.cssProps[name] || name;

    // cssFloat needs a special treatment
    if (name === "cssFloat") {
        name = "float";
    }

    // If a hook was provided get the computed value from there 在这里
    if (hooks && "get" in hooks && (ret = hooks.get(elem, true, extra)) !== undefined) {
        return ret;

        // Otherwise, if a way to get the computed value exists, use that
    } else if (curCSS) {
        return curCSS(elem, name);
    }
}