How to add dynamic orderby expression into query?

Question

I have dynamic order by expression. I have 2 paramter, one is order by and order by direction. When I am passing orderby orderBy, orderDirec it will not work. Can you please help me, how to do order by with 2 paramter?

public async Task<IPagedList<FixedAssetDepreciationDetail>> GetDepreciationDetailAsync(int companyId, string filterText = null,
            string orderBy = null, string orderDirec = "asc", int pageIndex = 0,
            int pageSize = int.MaxValue, int? fixedAssetID = null)
        {
            var query = from a in _depreciationDetailRepository.Table
                        join b in _depreciationRepository.Table on a.DepreciationID equals b.ID
                        join c in _fixedAssetRepository.Table on a.FixedAssetID equals c.ID
                        where b.IsActive && !b.IsDeleted
                        && a.CompanyID == companyId
                        && b.CompanyID == companyId
                        && (a.FixedAssetID == fixedAssetID || fixedAssetID == null)
                        orderby orderBy, orderDirec
                        select FixedAssetDepreciationDetail.Build(a, c, b);
            return await query.ToPagedListAsync(pageIndex, pageSize, orderBy, orderDirec);
        }

Right now, I am doing with below way, but it will not work when T.FixedAssetDepreciation.Year. T is Main class and second is child class object.

public static class IOrderQueryable
   {
       public static IQueryable<T> OrderByQuery<T>(this IQueryable<T> source, string dir, string sortColumn)
       {
           if (string.IsNullOrWhiteSpace(sortColumn))
               sortColumn = "ID";
           if (string.IsNullOrWhiteSpace(dir))
               dir = "ASC";
           Func<T, object> OrderByExp = GetOrderByExpression<T>(sortColumn);
           if (OrderByExp == null)
               return source;
           return dir.ToUpper() == "ASC" ? source.OrderBy(OrderByExp).AsQueryable() : source.OrderByDescending(OrderByExp).AsQueryable();
       }

       private static Func<T, object> GetOrderByExpression<T>(string sortColumn)
       {
           Func<T, object> orderByExpr = null;
           if (!string.IsNullOrEmpty(sortColumn))
           {
               Type sponsorResultType = typeof(T);
               if (sponsorResultType.GetProperties().Any(prop => prop.Name == sortColumn))
               {
                   System.Reflection.PropertyInfo pinfo = sponsorResultType.GetProperty(sortColumn);
                   orderByExpr = (data => pinfo.GetValue(data, null));
               }
           }
           return orderByExpr;
       }
   }