Sure:

ClassLib.cs:
public class ClassLib
{
   public const int Const = 1;
   public static readonly int ReadOnly = 1;
}

Test.cs:
using System;

class Test
{
   static void Main()
   {
       Console.WriteLine ("Const: {0}", ClassLib.Const);
       Console.WriteLine ("ReadOnly: {0}", ClassLib.ReadOnly);
   }
}

Compile and run:
csc /target:library ClassLib.cs
csc /r:ClassLib.dll Test.cs
test

Output:
Const: 1
ReadOnly: 1

Now change both values in ClassLib.cs to 2, and recompile *just
classlib*.

Rerun the test, and you'll get:

Const: 1
ReadOnly: 2

The value of Const hasn't been updated, because when Test.exe was
compiled, the value was copied straight into the executable - at
runtime, it isn't being fetched from ClassLib (which it is for the
readonly field).

Does that help?