C#

Boxing and unboxing

int foo = 42;         // Value type.
object bar = foo;     // foo is boxed to bar.
int foo2 = (int)bar;  // Unboxed back to value type.

Hello world

using System;

class Program
{
    public static void Main(string[] args)
    {
        Console.WriteLine("Hello, world!");
        Console.WriteLine("Is almost the same argument!");
    }
}

hello world dialog box

using System;
using System.Drawing;

public class Example
{
    public static Image img;

    public static void Main()
    {
        img = Image.FromFile("Image.png");
    }
}