Decimal.ToUInt64-Methode

using System;

class Example
{
   public static void Main( )
   {
      decimal[] values = { 123m, new Decimal(123000, 0, 0, false, 3), 
                           123.999m, 18446744073709551615.999m, 
                           18446744073709551616m, 9223372036854775807.999m, 
                           9223372036854775808m, -0.999m, -1m, 
                           -9223372036854775808.999m, 
                           -9223372036854775809m };

      foreach (var value in values) {
         try {             
            ulong number = Decimal.ToUInt64(value);
            Console.WriteLine("{0} --> {1}", value, number);       
         }
         catch (OverflowException e)
         {
             Console.WriteLine("{0}: {1}", e.GetType().Name, value);
         }   
      }
   }
}
// The example displays the following output:
//     123 --> 123
//     123.000 --> 123
//     123.999 --> 123
//     18446744073709551615.999 --> 18446744073709551615
//     OverflowException: 18446744073709551616
//     9223372036854775807.999 --> 9223372036854775807
//     9223372036854775808 --> 9223372036854775808
//     -0.999 --> 0
//     OverflowException: -1
//     OverflowException: -9223372036854775808.999
//     OverflowException: -9223372036854775809