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本文是写给C#新手,老手就勿看了,讲的实际上就是LINQ,谢谢一楼的提醒。
很多时候,从一个关系表中挑出一个我们需要的元素列表采用SQL语句是再容易不过的了,其实C#的List中也可以采用类似的方法,虽然List中集成了Select(), Where()等语句,不过如果你的判断规则较为复杂,或者想要看起来一目了然,以下的方法也是可行的:
首先假设你有一个类
public class People { public string Name { get; set; } public int Age { get; set; } }
并且有一些初始化语句
List<People> PeopleList = new List<People>(); PeopleList.Add(new People() { Name = "Haocheng Wu", Age = 24 }); PeopleList.Add(new People() { Name = "Haocheng Wu", Age = 25 }); PeopleList.Add(new People() { Name = "James Wu", Age = 23 });
你就可以采用下面类似于SQL语句的方法进行select
List<string> SubPeopleNameList1 = (from people in PeopleList where people.Name == "Haocheng Wu" && people.Age == 24 select people.Name).ToList<string>();
List<string> SubPeopleNameList2 = PeopleList.Where(people => people.Name == "Haocheng Wu" && people.Age == 24).Select(people => people.Name).ToList();
不过显然第一种方法更加一目了然,尤其是当判断条件相当复杂的时候就更加有用了
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原文地址:http://www.cnblogs.com/sky6699/p/4882185.html