linq给现有class对象赋值

最新推荐文章于 2025-04-26 08:36:40 发布

原创最新推荐文章于 2025-04-26 08:36:40 发布 · 1.9k 阅读

0 ·

CC 4.0 BY-SA版权

文章标签：

#linq #class对象

c# 专栏收录该内容

82 篇文章

订阅专栏

本文通过C#示例代码展示了如何使用Linq进行数据查询，包括从学生列表中筛选特定班级的学生，并展示如何将查询结果映射到新的类对象。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Security;
using System.Security.Cryptography.X509Certificates;
using System.Text;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            List<StudentDemo> student_list = GetStudentList();
            List<ClassDemo> class_list = GetClassList();

            //linq给新的class对象赋值
            var query1 = from s in student_list
                         join c in class_list on s.class_id equals c.class_id
                         where c.class_id.Equals(1) || c.class_id.Equals(2)
                         select new StudentNew
                         {
                             student_id = s.student_id,
                             student_name = s.student_name,
                             class_id = s.class_id,
                             class_name = c.class_name,
                         };
            //linq原有的class对象赋值
            var query2 = from s in student_list
                         join c in class_list on s.class_id equals c.class_id
                         where c.class_id.Equals(1) || c.class_id.Equals(2)
                         select s;
        }
        private static List<ClassDemo> GetClassList()
        {
            List<ClassDemo> list = new List<ClassDemo>();
            list.Add(new ClassDemo
            {
                class_id = 1,
                class_name = "班级1"
            });
            list.Add(new ClassDemo
            {
                class_id = 2,
                class_name = "班级2"
            });
            list.Add(new ClassDemo
            {
                class_id = 3,
                class_name = "班级3"
            });
            return list;
        }
        private static List<StudentDemo> GetStudentList()
        {
            List<StudentDemo> list = new List<StudentDemo>();
            list.Add(new StudentDemo
            {
                student_id = 1,
                student_name = "学生1",
                class_id = 1
            });
            list.Add(new StudentDemo
            {
                student_id = 2,
                student_name = "学生2",
                class_id = 1
            });
            list.Add(new StudentDemo
            {
                student_id = 3,
                student_name = "学生3",
                class_id = 2
            });
            list.Add(new StudentDemo
            {
                student_id = 4,
                student_name = "学生4",
                class_id = 2
            });
            list.Add(new StudentDemo
            {
                student_id = 5,
                student_name = "学生5",
                class_id = 3
            });
            return list;
        }
    }
    public class StudentDemo
    {
        public int student_id { get; set; }
        public string student_name { get; set; }
        public int class_id { get; set; }
    }
    public class ClassDemo
    {
        public int class_id { get; set; }
        public string class_name { get; set; }
    }
    public class StudentNew : StudentDemo
    {
        public string class_name { get; set; }
    }
}