C#: 타임 아웃으로 URL 다운로드
-
08-07-2019 - |
문제
.NET에서 가장 좋은 방법은 무엇입니까? 나는 항상 내가 필요한 것을 잊어 버린다 Dispose()
(또는 랩 using
).
편집 : 오랜 시간을 사용한 후 WebRequest
, 나는 커스터마이징에 대해 알게되었습니다 WebClient
. 훨씬 낫다.
해결책 3
Thomas Levesque의 의견에 따라 여기, 더 간단하고 일반적인 솔루션이 있습니다.
우리는 a를 만듭니다 WebClient
타임 아웃 지원으로 서브 클래스, 우리는 모든 것을 얻습니다. 웹 클라이언트의 선함.
public class WebClientWithTimeout : WebClient
{
private readonly int timeoutMilliseconds;
public WebClientWithTimeout(int timeoutMilliseconds)
{
this.timeoutMilliseconds = timeoutMilliseconds;
}
protected override WebRequest GetWebRequest(Uri address)
{
var result = base.GetWebRequest(address);
result.Timeout = timeoutMilliseconds;
return result;
}
}
샘플 사용 :
public string GetRequest(Uri uri, int timeoutMilliseconds)
{
using (var client = new WebClientWithTimeout(timeoutMilliseconds))
{
return client.DownloadString();
}
}
다른 팁
동기화 방법 :
var request = HttpWebRequest.Create("http://www.contoso.com");
request.Timeout = 50000;
using (var response = request.GetResponse())
{
//your code here
}
비동기적인 방법을 가질 수도 있습니다.
using System;
using System.Net;
using System.IO;
using System.Text;
using System.Threading;
public class RequestState
{
// This class stores the State of the request.
const int BUFFER_SIZE = 1024;
public StringBuilder requestData;
public byte[] BufferRead;
public HttpWebRequest request;
public HttpWebResponse response;
public Stream streamResponse;
public RequestState()
{
BufferRead = new byte[BUFFER_SIZE];
requestData = new StringBuilder("");
request = null;
streamResponse = null;
}
}
class HttpWebRequest_BeginGetResponse
{
public static ManualResetEvent allDone = new ManualResetEvent(false);
const int BUFFER_SIZE = 1024;
const int DefaultTimeout = 2 * 60 * 1000; // 2 minutes timeout
// Abort the request if the timer fires.
private static void TimeoutCallback(object state, bool timedOut)
{
if (timedOut)
{
HttpWebRequest request = state as HttpWebRequest;
if (request != null)
{
request.Abort();
}
}
}
static void Main()
{
try
{
// Create a HttpWebrequest object to the desired URL.
HttpWebRequest myHttpWebRequest = (HttpWebRequest)WebRequest.Create("http://www.contoso.com");
myHttpWebRequest.ReadWriteTimeout = DefaultTimeout;
// Create an instance of the RequestState and assign the previous myHttpWebRequest
// object to its request field.
RequestState myRequestState = new RequestState();
myRequestState.request = myHttpWebRequest;
// Start the asynchronous request.
IAsyncResult result =
(IAsyncResult)myHttpWebRequest.BeginGetResponse(new AsyncCallback(RespCallback), myRequestState);
// this line implements the timeout, if there is a timeout, the callback fires and the request becomes aborted
ThreadPool.RegisterWaitForSingleObject(result.AsyncWaitHandle, new WaitOrTimerCallback(TimeoutCallback), myHttpWebRequest, DefaultTimeout, true);
// The response came in the allowed time. The work processing will happen in the
// callback function.
allDone.WaitOne();
// Release the HttpWebResponse resource.
myRequestState.response.Close();
}
catch (WebException e)
{
Console.WriteLine("\nMain Exception raised!");
Console.WriteLine("\nMessage:{0}", e.Message);
Console.WriteLine("\nStatus:{0}", e.Status);
Console.WriteLine("Press any key to continue..........");
}
catch (Exception e)
{
Console.WriteLine("\nMain Exception raised!");
Console.WriteLine("Source :{0} ", e.Source);
Console.WriteLine("Message :{0} ", e.Message);
Console.WriteLine("Press any key to continue..........");
Console.Read();
}
}
private static void RespCallback(IAsyncResult asynchronousResult)
{
try
{
// State of request is asynchronous.
RequestState myRequestState = (RequestState)asynchronousResult.AsyncState;
HttpWebRequest myHttpWebRequest = myRequestState.request;
myRequestState.response = (HttpWebResponse)myHttpWebRequest.EndGetResponse(asynchronousResult);
// Read the response into a Stream object.
Stream responseStream = myRequestState.response.GetResponseStream();
myRequestState.streamResponse = responseStream;
// Begin the Reading of the contents of the HTML page and print it to the console.
IAsyncResult asynchronousInputRead = responseStream.BeginRead(myRequestState.BufferRead, 0, BUFFER_SIZE, new AsyncCallback(ReadCallBack), myRequestState);
return;
}
catch (WebException e)
{
Console.WriteLine("\nRespCallback Exception raised!");
Console.WriteLine("\nMessage:{0}", e.Message);
Console.WriteLine("\nStatus:{0}", e.Status);
}
allDone.Set();
}
private static void ReadCallBack(IAsyncResult asyncResult)
{
try
{
RequestState myRequestState = (RequestState)asyncResult.AsyncState;
Stream responseStream = myRequestState.streamResponse;
int read = responseStream.EndRead(asyncResult);
// Read the HTML page and then print it to the console.
if (read > 0)
{
myRequestState.requestData.Append(Encoding.ASCII.GetString(myRequestState.BufferRead, 0, read));
IAsyncResult asynchronousResult = responseStream.BeginRead(myRequestState.BufferRead, 0, BUFFER_SIZE, new AsyncCallback(ReadCallBack), myRequestState);
return;
}
else
{
Console.WriteLine("\nThe contents of the Html page are : ");
if (myRequestState.requestData.Length > 1)
{
string stringContent;
stringContent = myRequestState.requestData.ToString();
Console.WriteLine(stringContent);
}
Console.WriteLine("Press any key to continue..........");
Console.ReadLine();
responseStream.Close();
}
}
catch (WebException e)
{
Console.WriteLine("\nReadCallBack Exception raised!");
Console.WriteLine("\nMessage:{0}", e.Message);
Console.WriteLine("\nStatus:{0}", e.Status);
}
allDone.Set();
}
}
여기에 내가 사용하는 것이 있습니다. 효과가있는 것 같습니다. 그러나 그것이 가장 좋은 방법인지 모르겠습니다.
public string GetRequest(Uri uri, int timeoutMilliseconds)
{
var request = System.Net.WebRequest.Create(uri);
request.Timeout = timeoutMilliseconds;
using (var response = request.GetResponse())
using (var stream = response.GetResponseStream())
using (var reader = new System.IO.StreamReader(stream))
{
return reader.ReadToEnd();
}
}
System.net.webclient를 분리 된 스레드로 실행하고 최대 시간 후에 타이머를 제거하십시오.
제휴하지 않습니다 StackOverflow