4.2 特殊核算单元绩效测算表，获取数据错误

performance/Performance.Services/SheetSevice.cs

@@ -98,8 +98,8 @@ public SheetExportResponse SheetExport(int sheetID)
 
         private void CommonExport(int sheetID, SheetExportResponse response)
         {
-            var headList = _perforImHeaderRepository.GetEntities(t => t.SheetID == sheetID).OrderBy(t => t.PointCell);
-
+            var headList = _perforImHeaderRepository.GetEntities(t => t.SheetID == sheetID);
+            headList = headList != null ? headList.OrderBy(t => t.PointCell).ToList() : headList;
             var dataList = _perforImDataRepository.GetEntities(t => t.SheetID == sheetID);
             if (dataList == null || dataList.Count == 0) return;