animateBackground-plugin

        (function ($) {
            if (!document.defaultView || !document.defaultView.getComputedStyle) {
                var oldCurCSS = jQuery.curCSS;
                jQuery.curCSS = function (elem, name, force) {
                    if (name === 'background-position') {
                        name = 'backgroundPosition';
                    }
                    if (name !== 'backgroundPosition' || !elem.currentStyle || elem.currentStyle[name]) {
                        return oldCurCSS.apply(this, arguments);
                    }
                    var style = elem.style;
                    if (!force && style && style[name]) {
                        return style[name];
                    }
                    return oldCurCSS(elem, 'backgroundPositionX', force) + ' ' + oldCurCSS(elem, 'backgroundPositionY', force);
                };
            }

            var oldAnim = $.fn.animate;
            $.fn.animate = function (prop) {
                if ('background-position' in prop) {
                    prop.backgroundPosition = prop['background-position'];
                    delete prop['background-position'];
                }
                if ('backgroundPosition' in prop) {
                    prop.backgroundPosition = '(' + prop.backgroundPosition + ')';
                }
                return oldAnim.apply(this, arguments);
            };

            function toArray(strg) {
                strg = strg.replace(/left|top/g, '0px');
                strg = strg.replace(/right|bottom/g, '100%');
                strg = strg.replace(/([-\.]+)(\s|\)|$)/g, "$1px$2");
                var res = strg.match(/(-?[-\.]+)(px|\%|em|pt)\s(-?[-\.]+)(px|\%|em|pt)/);
                return [parseFloat(res[], ), res[], parseFloat(res[], ), res[]];
            }

            $.fx.step.backgroundPosition = function (fx) {
                if (!fx.bgPosReady) {
                    var start = $.curCSS(fx.elem, 'backgroundPosition');

                    if (!start) {//FF2 no inline-style fallback
                        start = '0px 0px';
                    }

                    start = toArray(start);

                    fx.start = [start[], start[]];

                    var end = toArray(fx.end);
                    fx.end = [end[], end[]];

                    fx.unit = [end[], end[]];
                    fx.bgPosReady = true;
                }

                var nowPosX = [];
                nowPosX[] = ((fx.end[] - fx.start[]) * fx.pos) + fx.start[] + fx.unit[];
                nowPosX[] = ((fx.end[] - fx.start[]) * fx.pos) + fx.start[] + fx.unit[];
                fx.elem.style.backgroundPosition = nowPosX[] + ' ' + nowPosX[];
            };
        })(jQuery);

调用示例：

//动画调用示例
$("#viewBody").animate({ backgroundPosition: '(520px 0)' });