[英]How to add dynamic sort by direction to NHibernate queryover
I am trying to add dynamic order by direction to my nhibernate queryover. 我试图将方向动态顺序添加到我的nhibernate queryover中。 Can anyone help how to do this? 谁能帮忙做到这一点? I was able to add dynamic orderby field. 我能够添加动态orderby字段。 but dont know how to do the order by direction. 但不知道如何按方向进行排序。 Please find below my code: 请在下面找到我的代码:
if (!string.IsNullOrEmpty(sortField))
{
var sortByProperty = Helper.GetSortByProperty(sortField);
if (sortByProperty != null)
{
query.OrderBy(x => sortByProperty.GetValue(x, null));
}
}
var result = query.Skip(pageIndex*pageSize)
.Take(pageSize)
.Future<Member>();
The way I have done this is, passing in a ListSortDirection
type variable to the function that is doing the query. 我这样做的方法是,将ListSortDirection
类型变量传递给正在执行查询的函数。
So then you could apply the 因此,您可以应用
OrderBy()
which: OrderBy()
: Sorts the elements of a sequence in ascending order according to a key. 根据键以升序对序列的元素进行排序。
OrderByDescending()
which: OrderByDescending()
: Sorts the elements of a sequence in descending order according to a key. 根据键以降序对序列的元素进行排序。
on your IQueryable<T>
depending on the values from ListSortDirection.Ascending
or ListSortDirection.Descending
. 在IQueryable<T>
上,具体取决于ListSortDirection.Ascending
或ListSortDirection.Descending
的值。
As requested by OP in comments, added sample generic code: 根据OP在注释中的要求,添加了示例通用代码:
public IList<T> GetEntityList<T>(Expression<Func<T, bool>> whereExpression, Expression<Func<T, object>> orderByExpression, ListSortDirection orderDirection, int totalPages, int start, int limit)
{
IList<T> returnVar;
using (var session = _nhibernate.OpenSession())
{
var firstQueryable = session.Query<T>().Where(whereExpression);
IQueryable<T> secondQueryable = orderDirection == ListSortDirection.Ascending ? firstQueryable.OrderBy(orderByExpression) : firstQueryable.OrderByDescending(orderByExpression);
returnVar = totalPages > 0 ? secondQueryable.Skip(start).Take(limit).ToList() : secondQueryable.ToList();
}
return returnVar;
}
QueryOver
API, for instance you can use the .OrderBy(orderByExpression).Desc
for reverse sorting.
例如,要解决OP的注释问题,可以使用QueryOver
API的.OrderBy(orderByExpression).Desc
进行反向排序。
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