docs: function(createFlag) {
  			var oThis = this,visibleIndex = 0,gridCompColumnArr,trStyle = '';
  			if(this.options.maxHeaderLevel >1){
  				trStyle = 'style="height:' + this.headerHeight + 'px;"';
  			}
  			var htmlStr = '<tr role="row" ' + trStyle + '>';
  			if(createFlag == 'fixed'){
  				gridCompColumnArr = this.gridCompColumnFixedArr;
  			}else{
  				gridCompColumnArr = this.gridCompColumnArr;
  			}
  			$.each(gridCompColumnArr, function(i) {
  				var vi = visibleIndex,displayStyle = '';
  				if(this.options.visible == false){
  					vi = -1;
  					displayStyle = 'style="display:none;"';
  				}else{
  					visibleIndex++;
  				}
  				// 低版本浏览器不支持th position为relative，因此加入空div
  				htmlStr += '<th role="columnheader" data-filed="' + this.options.field + '" rowspan="1" class="u-grid-header-th" ' + displayStyle + 'field="' + this.options.field + '" index="' + i + '" visibleIndex="' + vi + '"><div style="position:relative;">';
  				var colorStype = '';
  				if(this.options.headerColor){
  					colorStype = 'style="color:' + this.options.headerColor + '"';
  				}
  				htmlStr += '<div class="u-grid-header-link" field="' + this.options.field + '" title="' + this.options.title + '" ' + colorStype + '>' + this.options.title + '</div>';
  				/*if(oThis.options.columnMenu && createFlag != 'fixed'){
  					// 创建右侧按钮图标
  					htmlStr += '<div class="u-grid-header-columnmenu fa fa-bars " field="' + this.options.field + '" style="display:none;"></div>';
  				}*/
  				htmlStr += '</div></th>';
  			});
  
  			htmlStr += '</tr>';
  			return htmlStr;
  		}