我需要帮助使用Threading和异步HttpWebRequest调用创建Windows服务。我之前创建了一些C＃windows服务但从未使用过线程。此外，我似乎正忙着使用HttpWebRequest进行异步调用。我已经用Google搜索了这个以及在这个网站上查看。我找不到任何有帮助的东西。这主要是因为我似乎无法将其他问题中的内容用于我的具体示例。
请记住，基于我在这个特定领域缺乏知识以及试图解决问题，我可能会重叠。
主要流程是在onStart期间获取网址列表。通常，此列表将从_facade.GetUrls调用中检索。然后，在每个时间间隔调用scanSites。向每个URL发出请求，然后将结果保存到_facade.SaveUrlResponse中的数据库中。
我的问题是，当我调试它时，似乎我陷入无休止的循环中。我不确定如何/在哪里这样做。提前谢谢。
这就是我所拥有的：
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Net;
using System.ServiceProcess;
using System.Threading;
using URLValidation.BusinessManager.Facade;
using URLValidation.BusinessManager.Model;
namespace URLValidation
{
partial class URLValidation : ServiceBase
{
#region " class variables "
private System.Timers.Timer _timer;
private List<UrlModel> _url_List = null;
private Facade _facade;
private Thread _t;
private int _x;
#endregion
public URLValidation()
{
_facade = new Facade();
InitializeComponent();
}
protected override void OnStart(string[] args)
{
try
{
_url_List = new List<UrlModel>
{
new UrlModel(address: "http://www.google.com", addressID: 1),
new UrlModel(address: "http://www.microsoft.com", addressID: 2),
new UrlModel(address: "http://www.stackoverflow.com", addressID: 3)
};
resetTimer();
GC.KeepAlive(_timer);
}
catch (Exception ex)
{
throw ex;
}
}
private void resetTimer()
{
try
{
_timer = new System.Timers.Timer();
_timer.Interval = 10000;//1800000; //30 minutes
_timer.Start();
_timer.Enabled = true;
_timer.Elapsed += scanSites;
}
catch (Exception ex)
{
throw ex;
}
}
private void scanSites(object sender, System.Timers.ElapsedEventArgs e)
{
_timer.Stop();
_x = 0;
_t = new Thread(new ThreadStart(scanSites));
_t.IsBackground = true;
_t.Start();
}
private void scanSites()
{
try
{
foreach (UrlModel url in _url_List)
{
_x += 1;
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url.Address);
request.Method = "HEAD";
RequestModel requestModel = new RequestModel(request, url);
IAsyncResult result = request.BeginGetResponse(new AsyncCallback(saveUrlResponse), requestModel);
ThreadPool.RegisterWaitForSingleObject
(
result.AsyncWaitHandle,
new WaitOrTimerCallback(ScanTimeoutCallback),
requestModel,
(30 * 1000), // 30 second timeout
true
);
}
}
catch (Exception ex)
{
throw ex;
}
}
private void saveUrlResponse(IAsyncResult result)
{
//grab the custom state object
RequestModel requestModel = (RequestModel)result.AsyncState;
HttpWebRequest request = (HttpWebRequest)requestModel.Request;
//get the Response
HttpWebResponse response = (HttpWebResponse)request.EndGetResponse(result);
// process the response...
ResponseModel responseModel = new ResponseModel(request, response, requestModel.UrlModel.AddressID);
_facade.SaveUrlResponse(responseModel);
}
private void ScanTimeoutCallback(object requestModel, bool timedOut)
{
if (timedOut)
{
RequestModel reqState = (RequestModel)requestModel;
if (reqState != null)
reqState.Request.Abort();
}
if (_x == _url_List.Count)
{
resetTimer();
}
}
protected override void OnStop()
{
// TODO: Add code here to perform any tear-down necessary to stop your service.
}
}
}
好的，我想我到了某个地方。我已将代码移至控制台应用程序。我可以使用GetResponse（sync）和BeginGetResponse（async）将结果保存到数据库中。据我所知，我相信这是一个很好的解决方案。有人可以验证这一点，如果您将其移至Windows服务后预见到任何问题，请告诉我。这是新代码
using System;
using System.Collections.Generic;
using System.Net;
using System.Threading;
namespace ConsoleApplication2
{
static class Program
{
private static List<UrlModel> _url_List = null;
private static Object _acctLock = new object();
private static Facade _facade = new Facade();
static void Main(string[] args)
{
_url_List = new List<UrlModel>
{
new UrlModel(address: "http://www.microsoft.com", addressID: 1),
new UrlModel(address: "http://www.google.com", addressID: 2),
new UrlModel(address: "http://www.stackoverflow.com", addressID: 3)
};
lockThreadAndGetUrlStatus(_url_List);
Console.ReadLine();
}
static void lockThreadAndGetUrlStatus(List<UrlModel> _url_List)
{
Thread[] threads;
try
{
threads = new Thread[_url_List.Count];
Thread.CurrentThread.Name = "main";
int i = 0;
foreach (UrlModel url in _url_List)
{
//Thread t = new Thread(() => scanSites(url));
Thread t = new Thread(() => scanSitesWithAsync(url));
t.Name = i.ToString();
threads[i] = t;
i += 1;
}
for (i = 0; i < _url_List.Count; i++)
{
Console.WriteLine("Thread {0} Alive : {1}", threads[i].Name, threads[i].IsAlive);
threads[i].Start();
Console.WriteLine("Thread {0} Alive : {1}", threads[i].Name, threads[i].IsAlive);
}
Console.WriteLine("Current Priority : {0}", Thread.CurrentThread.Priority);
Console.WriteLine("Thread {0} Ending", Thread.CurrentThread.Name);
}
catch (Exception ex)
{
throw ex;
}
}
static void scanSitesWithAsync(UrlModel url)
{
try
{
lock (_acctLock)
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url.Address);
request.Method = "HEAD";
RequestModel requestModel = new RequestModel(request, url);
IAsyncResult result = request.BeginGetResponse(new AsyncCallback(saveUrlResponseWithAsync), requestModel);
ThreadPool.RegisterWaitForSingleObject
(
result.AsyncWaitHandle,
new WaitOrTimerCallback(scanTimeoutCallback),
requestModel, 30000, true
);
}
}
catch (Exception ex)
{
throw ex;
}
}
static void saveUrlResponseWithAsync(IAsyncResult result)
{
try
{
RequestModel requestModel = (RequestModel)result.AsyncState;
HttpWebRequest request = (HttpWebRequest)requestModel.Request;
//get the Response
HttpWebResponse response = (HttpWebResponse)request.EndGetResponse(result);
// process the response...
ResponseModel responseModel = new ResponseModel(requestModel.Request, response, requestModel.UrlModel.AddressID);
_facade.SaveUrlResponse(responseModel);
Console.WriteLine(response.StatusCode);
}
catch (Exception ex)
{
throw ex;
}
}
static void scanTimeoutCallback(object requestModel, bool timedOut)
{
try
{
if (timedOut)
{
RequestModel reqState = (RequestModel)requestModel;
if (reqState != null)
reqState.Request.Abort();
}
}
catch (Exception ex)
{
throw ex;
}
}
}
}
答案 0 :(得分：0)
看起来您正在尝试同时发出3个异步请求。默认情况下，HTTP / 1.1协议仅指定2个连接