C#内置泛型委托之Action委托

using System.Runtime.CompilerServices;

namespace System
{
    //
    // 摘要:
    //     封装一个方法，该方法不具有参数且不返回值。
    [TypeForwardedFrom("System.Core, Version=3.5.0.0, Culture=Neutral, PublicKeyToken=b77a5c561934e089")]
    public delegate void Action();
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ActionDemo
{
    class Program
    {
        static void Main(string[] args)
        {
            // 无参数无返回值的委托
            Action action1 = new Action(ActionWithNoParaNoReturn);
            action1();
            Console.WriteLine("----------------------------");
            // 使用delegate
            Action action2 = delegate { Console.WriteLine("这里是使用delegate"); };
            // 执行
            action2();
            Console.WriteLine("----------------------------");
            // 使用匿名委托
            Action action3 = () => { Console.WriteLine("这里是匿名委托"); };
            action3();
            Console.WriteLine("----------------------------");
            // 有参数无返回值的委托
            Action<int> action4 = new Action<int>(ActionWithPara);
            action4(23);
            Console.WriteLine("----------------------------");
            // 使用delegate
            Action<int> action5 = delegate (int i) { Console.WriteLine($"这里是使用delegate的委托，参数值是：{i}"); };
            action5(45);
            Console.WriteLine("----------------------------");
            // 使用匿名委托
            Action<string> action6 = (string s) => { Console.WriteLine($"这里是使用匿名委托，参数值是:{s}"); };
            action6("345");
            Console.WriteLine("----------------------------");
            // 多个参数无返回值的委托
            Action<int, string> action7 = new Action<int, string>(ActionWithMulitPara);
            action7(7, "abc");
            Console.WriteLine("----------------------------");
            // 使用delegate
            Action<int, int, string> action8 = delegate (int i1, int i2, string s) 
            {
                Console.WriteLine($"这里是三个参数的Action委托，参数1的值是：{i1}，参数2的值是：{i2}，参数3的值是：{s}");
            };
            action8(12, 34, "abc");
            Console.WriteLine("----------------------------");
            Action<int,int,string, string> action9 = (int i1,int i2, string s1,string s2) => 
            {
                Console.WriteLine($"这里是使用四个参数的委托，参数1的值是：{i1},参数2的值是：{i2}，参数3的值是：{s1}，参数4的值是：{s2}");
            };
            // 执行委托
            action9(34,56, "abc","def");
            Console.ReadKey();
        }




        static void ActionWithNoParaNoReturn()
        {
            Console.WriteLine("这是无参数无返回值的Action委托");
        }

        static void ActionWithPara(int i)
        {
            Console.WriteLine($"这里是有参数无返回值的委托，参数值是：{i}");
        }

        static void ActionWithMulitPara(int i,string s)
        {
            Console.WriteLine($"这里是有两个参数无返回值的委托，参数1的值是：{i}，参数2的值是：{s}");
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ActionDemo
{
    public class Student
    {
        public int Id { get; set; }

        public string Name { get; set; }

        public int Age { get; set; }

        public int Sex { get; set; }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ActionDemo
{
    public class ActionTest
    {
        public static void Test()
        {
            List<Student> list = new List<Student>()
            {
              new Student(){Id=1,Name="张三",Age=19,Sex=1},
              new Student(){Id=2,Name="李四",Age=20,Sex=2},
              new Student(){Id=3,Name="王五",Age=23,Sex=1},
              new Student(){Id=4,Name="赵六",Age=18,Sex=1}
            };

            // Action<Student>委托作为参数传递给ForEach()方法
            list.ForEach(student =>
            {
                Console.WriteLine($"姓名：{student.Name},年龄：{student.Age}");
            });
        }
    }
}

ActionTest.Test();