C#lambda表达式可以这样吗？

[CSY_Admin]

EF分页

public  IPage<TEntity> Page<TKey, TEntity>(int pageIndex, int pageSize, Expression<Func<TEntity, bool>> predicate, bool isAsc,
            Expression<Func<TEntity, TKey>> keySelector) where TEntity : class
        {
            using (BaseEntitiesContext context = new BaseEntitiesContext())
            {
                if (pageIndex <= 0 && pageSize <= 0)
                {
                    throw new Exception("pageIndex或pageSize不能小于等于0！");
                }
                IPage<TEntity> page = new Page<TEntity>()
                {
                    PageIndex = pageIndex,
                    PageSize = pageSize
                };
                int skip = (pageIndex - 1) * pageSize;
                if (predicate == null)
                {
                    FutureCount fcount = context.Set<TEntity>().FutureCount();
                    FutureQuery<TEntity> futureQuery = isAsc
                        ? context.Set<TEntity>().OrderBy(keySelector).Skip(skip).Take(pageSize).Future()
                        : context.Set<TEntity>().OrderByDescending(keySelector).Skip(skip).Take(pageSize).Future();
                    page.TotalItems = fcount.Value;
                    page.Items = futureQuery.ToList();
                    page.TotalPages = page.TotalItems / pageSize;
                    if ((page.TotalItems % pageSize) != 0) page.TotalPages++;
                }
                else
                {
                    var queryable = context.Set<TEntity>().Where(predicate);
                    FutureCount fcount = queryable.FutureCount();
                    FutureQuery<TEntity> futureQuery = isAsc
                        ? queryable.OrderBy(keySelector).Skip(skip).Take(pageSize).Future()
                        : queryable.OrderByDescending(keySelector).Skip(skip).Take(pageSize).Future();
                    page.TotalItems = fcount.Value;
                    page.Items = futureQuery.ToList();
                    page.TotalPages = page.TotalItems / pageSize;
                    if ((page.TotalItems % pageSize) != 0) page.TotalPages++;
                }
                return page;
            }
               
        }

正常使用

  using (BaseEntitiesContext context = new BaseEntitiesContext())
            {
                var result = context.Page<int?, TBR_Dictionaries>(1, 50, w => w.UPDATER == "00000000-0000-0000-0000-000000000000" , true, w => w.DIC_SORT);
}

入参为前端提供，后端解析成Lamada
比方说上面这个就是通过前端入参
{
pageIndex: 1
pageSize: 50
fliterItems：[{fieldName: "UPDATER", compare: "EQ", value: "00000000-0000-0000-0000-000000000000"}]
sortFiled: DIC_SORT
sortOrder: isAsc
}
解析而成，目前如果这里的 w.UPDATER == "00000000-0000-0000-0000-000000000000"可以写成 w["UPDATER"] == "00000000-0000-0000-0000-000000000000"这种变量形式，后台则不用写出过多的if，else判断组装lambda，请问下各位大牛可以这样去实现吗？

[threenewbee]

如果编译没有错误的话，我觉得可以。

[wanghui0380]

我们并不想讨论这个问题。我们更愿意说，别去折腾EF。 可以去看看GraphQL，看完GraphQL了你会发现他才是你这想法的入口（虽然要实现也要emit，也要iqueryable，也要exspresstion，但是我们的建议是先抬头看看天，看看路。别总盯着脚底） https://www.nuget.org/packages/GraphQL/3.0.0-preview-1648 https://www.nuget.org/packages/GraphQL.EntityFramework/11.0.0-beta.4

[正怒月神]

我当时是这样写的。

public virtual IQueryable<T> FindPageList<S>(int pageIndex, int pageSize, out int totalRecord, Expression<Func<T, bool>> whereLamdba, bool isAsc, Expression<Func<T, S>> orderLamdba)
        {
            var _list = dbEF.Set<T>().AsNoTracking().Where<T>(whereLamdba);
            totalRecord = _list.Count();
            if (isAsc) _list = _list.OrderBy<T, S>(orderLamdba).Skip<T>((pageIndex - 1) * pageSize).Take<T>(pageSize);
            else _list = _list.OrderByDescending<T, S>(orderLamdba).Skip<T>((pageIndex - 1) * pageSize).Take<T>(pageSize);
            return _list;
        }

[无语无]

我感觉应该没问题