getBoundingClientReact方法

rectObject = object.getBoundingClientRect(); // 返回元素的大小及其相对于视口的位置

/**
 * getBoundingClientRect 兼容IE7
 * @param {DOM Object} obj 
 */
function getBoundingClientRect(obj) {
    var boundingClientRect = obj.getBoundingClientRect();
    var newObj = {
        bottom: boundingClientRect.bottom,
        left: boundingClientRect.left,
        right: boundingClientRect.right,
        top: boundingClientRect.top
    }

	if (boundingClientRect.width) {
		newObj.width = boundingClientRect.width;
		newObj.height = boundingClientRect.height;
	} else {
		newObj.width = boundingClientRect.right - boundingClientRect.left;
		newObj.height = boundingClientRect.bottom - boundingClientRect.top;
    }
	return newObj;
}