线程池处理多线程

class Program
{
static void Main(string[] args)
{
const int FibonacciCalculations = 20;

// One event is used for each Fibonacci object.
ManualResetEvent[] doneEvents = new ManualResetEvent[FibonacciCalculations];
Fibonacci[] fibArray = new Fibonacci[FibonacciCalculations];
Random r = new Random();

// Configure and start threads using ThreadPool.
Console.WriteLine("发出 {0} 个任务...", FibonacciCalculations);
for (int i = 0; i < FibonacciCalculations; i++)
{
doneEvents[i] = new ManualResetEvent(false);
Fibonacci f = new Fibonacci(r.Next(20, 40), doneEvents[i]);
fibArray[i] = f;
ThreadPool.QueueUserWorkItem(f.ThreadPoolCallback, i);
}

// Wait for all threads in pool to calculate.
WaitHandle.WaitAll(doneEvents);
Console.WriteLine("所有的计算都是完整的");

// Display the results.
for (int i = 0; i < FibonacciCalculations; i++)
{
Fibonacci f = fibArray[i];
Console.WriteLine("斐波那契 ({0}) = {1}", f.N, f.FibOfN);
}

Console.ReadLine();
}
}

public class Fibonacci
{
private int _n;
private int _fibOfN;
private ManualResetEvent _doneEvent;

public int N { get { return _n; } }
public int FibOfN { get { return _fibOfN; } }

// Constructor.
public Fibonacci(int n, ManualResetEvent doneEvent)
{
_n = n;
_doneEvent = doneEvent;
}

// Wrapper method for use with thread pool.
public void ThreadPoolCallback(Object threadContext)
{
int threadIndex = (int)threadContext;
Console.WriteLine("线程 {0} 开始...", threadIndex);
_fibOfN = Calculate(_n);
Console.WriteLine("线程 {0} 计算结果.", threadIndex);
_doneEvent.Set();  //终止该线程
Console.WriteLine("线程{0}终止", threadIndex);

}

// Recursive method that calculates the Nth Fibonacci number.
public int Calculate(int n)
{
if (n <= 1)
{
return n;
}

return Calculate(n - 1) + Calculate(n - 2);
}
}