通过 Grid::combine 方法可以很方便的把任意两个以上的字段组合成一级表头

示例
<?phpprotected function grid(){return Grid::make(new Report(), function (Grid $grid) {// 第一个参数为一级表头字段名称,第二个字段为二级表头字段名称,二级表头字段最少设置两个$grid->combine('avgCost', ['avgMonthCost', 'avgQuarterCost', 'avgYearCost']);$grid->combine('avgVist', ['avgMonthVist', 'avgQuarterVist', 'avgYearVist']);// 设置样式$grid->combine('top', ['topCost', 'topVist', 'topIncr'])->style('color:#1867c0');$grid->column('content')->limit(50);$grid->column('cost')->sortable();$grid->column('avgMonthCost');$grid->column('avgQuarterCost')->setHeaderAttributes(['style' => 'color:#5b69bc']);$grid->column('avgYearCost');$grid->column('avgMonthVist');$grid->column('avgQuarterVist');$grid->column('avgYearVist');$grid->column('incrs');$grid->column('avgVists');$grid->column('topCost');$grid->column('topVist');$grid->column('topIncr');$grid->column('date')->sortable();});}
