Jquery实现仿腾讯娱乐频道焦点图(幻灯片)特效

        /**
         动画元素
         @param {Element} target 目标元素
         @param {String} key target样式
         @param {Number} start key初始值
         @param {Number} end key结束值
         @param {Number} speed 速度
         @param {Function} endFn 结束时的回调
         @param {String} u 样式单位
        **/
        actPX : function(obj,key,start,end,speed,endFn,u){
          if(typeof(u) == ‘undefined’){u = ‘px’};
          clearTimeout(obj[‘_extend_actPX’ + key.replace(/-.=/,’_’) + ‘_timeOut’]);
          if(start > end){
            speed = – Math.abs(speed);
          }else{
            speed = Math.abs(speed);
          };
          var now = start;
          var length = end – start;
          obj[‘_extend_actPX’ + key.replace(/-.=/,’_’) + ‘_timeOut’] = setTimeout(function(){
            now += speed;
            var space = end – now;
            if(start < end){
              if(space < length/3){
                speed = Math.ceil(space/3);
              };
              if(space <= 0){
                obj[key] = end + u;
                if(endFn){endFn()};
                return;
              };