使用NHibernate的QueryOver，你怎么可以加入红枣

Question

之间的类型安全限制考虑以下QueryOver（季度和中心的变量传递）：

QueryOver.Of<Activity>() 
     .Where(Restrictions.On<Activity>(a => a.StartDate).IsBetween(quarter.StartDate).And(quarter.EndDate) || 
       Restrictions.On<Activity>(a => a.EndDate).IsBetween(quarter.StartDate).And(quarter.EndDate) || 
       Restrictions.And(Restrictions.Lt("StartDate", quarter.StartDate), Restrictions.Gt("EndDate", quarter.EndDate))) //TODO: Refactor this to remove magic strings 
     .And(a => a.Centre == centre) 
     .OrderBy(a => a.Title).Asc; 

这个查询作品完美，但我想更改以下限制删除魔术字符串：

Restrictions.And(Restrictions.Lt("StartDate", quarter.StartDate), Restrictions.Gt("EndDate", quarter.EndDate)) 

这里是（剪断，为了简洁）的实体：

public class Quarter 
{ 
    public DateTime StartDate { get; set; } 
    public DateTime EndDate { get; set; } 

} 

public class Activity 
{ 
    public string Title { get; set; } 
    public Centre Centre { get; set; } 
    public DateTime StartDate { get; set; } 
    public DateTime EndDate { get; set; } 

} 

public class Centre 
{ 
    public string Name { get; set; } 
} 

那么，使用新的QueryOver扩展将使我能够删除这些魔术字符串的类型安全方式是什么？

Answer 1

这是你想要什么：

Restrictions.And(
    Restrictions.Lt(Projections.Property<Activity>(x => x.StartDate), 
        quarter.StartDate), 
    Restrictions.Gt(Projections.Property<Activity>(x => x.EndDate), 
        quarter.EndDate))) 

旁注：属性名是不是魔术字符串。