C#第一个helloworld程序

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 using System.Threading.Tasks;
 6 using System.Windows.Forms;
 7
 8 namespace helloworld
 9 {
10     class HelloWorld
11     {
12         public static void Main()
13         {
14             Console.WriteLine("This is My First C# Program Hello World!");
15             MessageBox.Show("Hello World!");
16             Console.ReadLine();
17         }
18     }
19 }