如何使用NHibernate的ICriteria API选择Random Row？

using NHibernate;
using NHibernate.Criterion;
using System;

public class RandomRowSelector
{
    private ISession _session;

    public RandomRowSelector(ISession session)
    {
        _session = session;
    }

    public T SelectRandomRow<T>() where T : class
    {
        ICriteria criteria = _session.CreateCriteria<T>();
        int count = criteria.SetProjection(Projections.RowCountInt64()).UniqueResult<long>();

        if (count == 0)
        {
            return null;
        }

        Random random = new Random();
        int randomIndex = random.Next(0, (int)count);

        criteria.SetMaxResults(1);
        criteria.SetFirstResult(randomIndex);

        return criteria.List<T>().FirstOrDefault();
    }
}