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📜  C＃3.0 匿名类型

📅  最后修改于: 2020-11-01 03:02:19             🧑  作者: Mango

C＃匿名类型

C＃匿名类型使我们可以创建具有只读属性的对象。匿名对象是没有显式类型的对象。 C＃编译器生成类型名称，并且仅可用于当前代码块。

要创建匿名类型，我们必须将new运算符与对象初始化程序一起使用。

C＃匿名类型示例

using System;
namespace CSharpFeatures
{
    class AnonymousTypesExample
    {
        public static void Main()
        {
            // Creating Anonymous Object
            var student = new { ID = 101, Name = "Peter", Email = "peter@example.com"};
            // Accessing object properties
            Console.WriteLine(student.ID);
            Console.WriteLine(student.Name);
            Console.WriteLine(student.Email);
        }
    }
}

输出：

101
Peter
peter@example.com

我们还可以在查询表达式中使用它来选择记录。在以下示例中，我们通过创建匿名类型来选择学生记录。

C＃匿名类型示例2

using System;
using System.Collections.Generic;
using System.Linq;
namespace CSharpFeatures
{
    class Student
    {
        public int ID { get; set; }
        public string Name { get; set; }
        public string Email { get; set; }
    }

    class AnonymousTypesExample
    {
        public static void Main()
        {
            List students = new List {
                new  Student{ ID=101, Name="Rahul", Email="rahul@example.com" },
                new  Student{ ID=102, Name="Peter", Email="peter@abc.com" },
                new  Student{ ID=103, Name="Irfan", Email="irfan@example.com" }
            };     
            var stquery =
            from student in students
            select new { student.ID, student.Name, student.Email }; // Creating Anonymous Types
            foreach (var st in stquery)
            {
                Console.WriteLine("ID = {0}, Name = {1}, Email = {2}", st.ID, st.Name, st.Email);
            }
        }
    }
}

输出：

ID = 101, Name = Rahul, Email = rahul@example.com
ID = 102, Name = Peter, Email = peter@abc.com
ID = 103, Name = Irfan, Email = irfan@example.com