(function( $ ){      var slider = function( elem , args ){          this.config = $.extend({              effect   : 'x', //效果  水平 - x              speed    : 600 , //动画速度              trigger  : 'mouseenter', //触发事件              callback : null , // 回调函数              view     : 7          }, args || {}  );          this.history = [];//记录移动的历史记录          this.index = 0;          this.el = elem;          this.length = this.el.find('li').length;//记录总长度          this.width = this.el.find('li').eq(0).outerWidth();//记录每一个单项的宽度          this.init();      }      slider.prototype = {          constructor : slider,          init : function(){              this.bindEvents();          },          bindEvents : function(){              this.prev();              this.next();          },          prev :  function(){              this.el.find('[data-type="left"]').click( $.proxy(function(){                  if( !this.history.length ) return;//如果记录为空，证明没有进行移动过,所以直接return                  this.index--;                  var step = this.history.pop();//取最后的移动步骤                  var move =  step * this.width;//算出移动宽度                  this.el.find("ul").animate( { "left" : "+="+move+"px" } , this.config.speed )              } , this));          },          next : function(){              this.el.find('[data-type="right"]').click( $.proxy(function(){                  //如果是当前的最后一页,直接return                  if(this.index == parseInt( this.length / this.config.view , 10 ) ){                      return;                  }                  this.index++;                  //这个计算很重要                  //计算 ( 下一页 * view ) 展示个数是否大于总长度 : 好比当前在第一页 (1+1) *7 > 12(总长度)                  //则this.step 赋值为取余 ,也就是剩下要移动的个数                  if( this.config.view * (this.index+1) > this.length ){                      this.step =  this.length%this.config.view;                  }else{                      //否则移动展示的个数                      this.step = this.config.view;                  }                  //记录移动的历史记录                  this.history.push(this.step);                  var move = -1 * this.step * this.width;                  this.el.find("ul").animate( { "left" : "+="+move+"px" } , this.config.speed )              } , this));          }      }      $.fn.slider = function( args ){          return this.each(function(){              var el = this;              var plugins = new slider( $( el ) , args );              $(el).data("slider" , plugins );          });      }  })(jQuery)