C#引入win32类库：Dllimport can help you to do something

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;

namespace Box
{
    class Program
    {
        [DllImport("User32.dll")]
       public  static extern int MessageBox(int hand, string custom,string title,int type);
        static void Main(string[] args)
        {
            MessageBox(0, "Good","Greeting" ,0);
            Console.ReadKey();
        }
    }
}

 

//just less than 10 lines but very useful,needs no form reference