我想根据子集合属性对集合进行排序。
//the subcollection
public class Salary
{
public int SalaryId {get;set;}
public int SalaryYear {get;set;}
public double SalaryValue {get;set;} //this is the field we want to sort the parent collection "Person"
}
//the main collection
public class Person
{
public int PersonId {get;set;}
public string PersonName {get;set;}
public List<Salary> Salaries {get;set;}
}
下面只是为了测试目的,我正在准备我的个人收藏,每个人都有薪水内部收藏:
List<Person> people = new List<Person>();
//add two salaries for Junior
people.Add(new Person { PersonId = 1, PersonName = "Junior" });
people[0].Salaries.Add(new Salary { SalaryId=1, SalaryYear=2011, SalaryValue=80000 });
people[0].Salaries.Add(new Salary { SalaryId=2, SalaryYear=2010, SalaryValue=70000 });
//add two salaries for Johanna
people.Add(new Person { PersonId = 2, PersonName = "Johanna" });
people[0].Salaries.Add(new Salary { SalaryId=3, SalaryYear=2011, SalaryValue=40000 });
people[0].Salaries.Add(new Salary { SalaryId=4, SalaryYear=2010, SalaryValue=30000 });
现在我们想要对 people 集合进行排序,但是使用他们内部集合 SalaryValue 作为参数。
如何对 List 进行排序但在 Salaries 内部集合上使用 LINQ/Lambda 表达式?
所以我会有:
PersonName: Johanna, SalaryValue=30000, SalaryYear=2010
PersonName: Johanna, SalaryValue=40000, SalaryYear=2011
PersonName: Junior, SalaryValue=70000, SalaryYear=2010
PersonName: Junior, SalaryValue=80000, SalaryYear=2011
最佳答案
对我来说,这看起来像:
var query = from person in people
from salary in person.Salaries
orderby salary.SalaryValue
select new { person, salary };
foreach (var pair in query)
{
Console.WriteLine(pair);
}
请注意,您并没有真正对一组人进行排序 - 您正在对一组(人,薪水)进行排序,这就是具有两个
from
的扁平化效果。条款确实如此。(以上不会提供完全相同的输出,但是一旦你得到了这个人和他们的薪水,你就可以得到其他值。)
关于linq - 如何根据子集合属性对集合进行排序,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/3471588/