static void Main(string[] args)
{
Console.WriteLine("--Calculate a Fibonacci number at a certain position (0-49)--");
char answer;
do
{
Console.Write("\nEnter a position to compute: ");
try
{
int num = Convert.ToInt32(Console.ReadLine());
if (num < 0 || num > 49)
{
Console.WriteLine("ERROR: Position should be an integer from 0 to 49.");
}
else
{
Calculate c = new Calculate(Fibonacci);
IAsyncResult iasResult = c.BeginInvoke(num, null, null);
// This message will keep printing until
// the Fibonacci() method is finished.
while (!iasResult.IsCompleted)
{
Console.WriteLine("Main() invoked on thread {0}.",
Thread.CurrentThread.ManagedThreadId);
Console.WriteLine("continuing to do work...");
Thread.Sleep(1000);
}
int result = c.EndInvoke(iasResult);
Console.WriteLine($"Fibonacci value at position {num}: {result}");
}
}
catch (FormatException)
{
Console.WriteLine("ERROR: A position should be an integer.");
}
finally
{
Console.Write("Do you want to continue? (Y or N) ");
answer = Convert.ToChar(Console.ReadLine());
}
} while (answer == 'y' || answer == 'Y');
Console.WriteLine("\nProgram Ended");
Console.WriteLine("\nPress <Enter> to quit...");
Console.ReadKey();
}