// The following demonstrates exception handling in cSharp
Set all projects in Solution to a Default Namespace of "csExceptionHandling"

// C# Console Application Project "csExceptionHandling"
// Set Project Refs to csMath1 & csMath2

using System;

namespace ExeceptionHandling
{
   class ExeceptionHandlingClient
   {
      static void Main(string[] args)
      {
         string answer;
         Math1 oMath1 = new Math1(); 
         Math2 oMath2 = new Math2(); 

         try
         {
            answer = oMath1.ByteAdd(255,2,true).ToString();
		// if X + Y > 256 AND 3rd argument is true then an error will be thrown
		// If oMath1 is changed to oMath2 the "Source" will indicate same.

            Console.Write("The answer was: " + answer); 
         }
         catch (OverflowException e)
         {
            string s = e.Source;
            Console.Write("Oops... we seem to have an overflow from [" + s + "]" );
         }
         catch (Exception e)
         {
            Console.Write("\nSource: " + e.Source );
            Console.Write("\nMessage: " + e.Message);
         }

         finally
         {
            Console.Write("\nPress Enter Key to Exit");
            Console.ReadLine();
         }
      }
   }
}
/////////////////////////////////////////////////////////////////////////////////////////

// C# Class Library Project "csMath1"
// 

using System;
namespace ExeceptionHandling
{
   public class Math1
   {
      public string ByteAdd(byte X , byte Y , bool chk)
      {
         string sSum;
         int intSum;
         intSum = X + Y;
         byte bSum; 

         if (chk==true) 
         {
            checked 
            {
               bSum = (byte)intSum;
            }
         }
         else 
         {
            unchecked
            {
               bSum = (byte)intSum;
            }
         }
         sSum = bSum.ToString(); 
         return sSum;
      }
   }
}

/////////////////////////////////////////////////////////////////////////////////////////

// 2nd C# Class Library Project same as the above except change "csMath1" to "csMath2" 
// 

using System;
namespace ExeceptionHandling
{
   public class Math2 ...

/////////////////////////////////////////////////////////////////////////////////////////