javascript获取标签样式（获取背景为例）

function getStyle(el){

    if(window.getComputedStyle){

        return window.getComputedStyle(el,null);

    }

    return el.currentStyle;

}

function getStyleValue(el, name){

    var style = getStyle(el);

    return style[name];

}

console.log(getStyle(document.body));

console.log(getStyleValue(document.body, "backgroundImage"));