C#的异步调用
时间：2010-09-01 来源：让大家开心的人
使用异步调用，某些时候可以提高性能，比如说写日志，对数据库进行操作的时候就可以使用异步操作的方式。这种方式相当于多线程并发运行，所以性能会有所提升。我后面会发篇随笔来使用异步调用的方法写日志。code:
using System;
namespace Sandals.Demo.AsynchronousCall
{
public static class AsyncDemo
{
//声明委托
private delegate string AsyncMethodCalledEventHander(int duration, out int threadId);
//create an instance of the delegate
private static AsyncMethodCalledEventHander eventHandler = new AsyncMethodCalledEventHander(MethodForAsyncCall);
/// <summary>
/// The method to be executed asynchronously
/// </summary>www.qichepeijian.com
/// <param name="duration">sleep duration for thread</param>
/// <param name="threadId">current thread id</param>
/// <returns></returns>
private static string MethodForAsyncCall(int duration, out int threadId)
{
Console.WriteLine("MethodForAsyncCall begin execute... ");
System.Threading.Thread.Sleep(duration);
threadId = System.Threading.Thread.CurrentThread.ManagedThreadId;
return String.Format("my execute time was {0} ", duration);
}
/// <summary>
/// this method for executing asyc method
/// </summary>
/// <param name="duration"></param>
/// <returns></returns>
public static IAsyncResult BeingRun(int duration)
{
int dumy;
IAsyncResult result = eventHandler.BeginInvoke(duration, out dumy, null, null);
return result;
}
/// <summary>
/// this methiod end the asyc method
/// <summary>
/// <param name="threadId"></param>
/// <param name="ar"></param>
/// <returns></returns>
public static string EndRun(out int threadId, IAsyncResult ar)
{
if (ar == null)
throw new NullReferenceException("parameter ar can not be a null");
return eventHandler.EndInvoke(out threadId, ar);
}
}
class Program
{
static void Main(string[] args)
{
IAsyncResult result = AsyncDemo.BeingRun(10000);
Console.WriteLine("the thread {0} continue to execute", System.Threading.Thread.CurrentThread.ManagedThreadId);
Console.WriteLine("the thread {0} begin to sleep, date: {1}", System.Threading.Thread.CurrentThread.ManagedThreadId, DateTime.Now);
System.Threading.Thread.Sleep(3000);
Console.WriteLine("the thread {0} sleep end, date: {1}", System.Threading.Thread.CurrentThread.ManagedThreadId, DateTime.Now);
int threadId = 0;
Console.WriteLine("call the mothod to end the ansychronous method");
Console.WriteLine("asynchronous method return value: {0}. thread id: {1}", AsyncDemo.EndRun(out threadId, result), threadId);
}
}
}
相关阅读 更多 +
