C# 循环,尝试->;捕获异常,直到它不';T

C# 循环,尝试->;捕获异常,直到它不';T,c#,loops,exception,try-catch,httpwebresponse,C#,Loops,Exception,Try Catch,Httpwebresponse,我有这个: return request.GetResponse() as HttpWebResponse; 当网站无法正常工作时,它有时会抛出异常。。(502错误) 这个网站只会关闭几秒钟 所以。。我需要做一个循环并尝试上面的方法,然后捕获异常 我试过这个: while (true) { try { return request.GetResponse() as HttpWebResponse; break; } catch

我有这个:

return request.GetResponse() as HttpWebResponse;
当网站无法正常工作时,它有时会抛出异常。。(502错误)

这个网站只会关闭几秒钟

所以。。我需要做一个循环并尝试上面的方法,然后捕获异常

我试过这个:

while (true)
{
    try
    {
        return request.GetResponse() as HttpWebResponse;
        break; 
    }
    catch
    {

    }
}

但是,这给了我:
在中断时检测到不可访问的代码。

正如其他人所提到的,
中断
是冗余的;删除它将消除您的警告。此外,您还应引入一个可恢复的系统,以避免在发生可恢复故障时占用您的系统(并用请求淹没服务器):

double millisecondsDelay = 10;
double delayMultiplyFactor = 2;
int allowedRetries = 10;

while (true)
{
    try
    {
        return request.GetResponse() as HttpWebResponse;
    }
    catch (Exception e)
    {
        if (e is /* RecoverableException*/ && allowedRetries-- > 0)
        {
            Thread.Sleep((int)millisecondsDelay);
            millisecondsDelay *= delayMultiplyFactor;
        }
        else
        {
            throw;
        }
    }
}

所以。。我去了,这个:

while (true)
        {
            try
            {
                return request.GetResponse() as HttpWebResponse;
            }
            catch (Exception e)
            {
                if (e is WebException && allowedRetries-- > 0)
                {
                    System.Console.WriteLine("Trying to Reconnect...");
                    Thread.Sleep((int)millisecondsDelay);
                    //millisecondsDelay *= delayMultiplyFactor;
                }
                else
                {
                    throw;
                }
            }
        }
但它被卡在了“试图重新连接…” 如果我重新启动它。。它立即连接

整个功能。。如果有帮助:

public static HttpWebResponse Request (string url, string method, NameValueCollection data = null, CookieContainer cookies = null, bool ajax = true)
    {
        HttpWebRequest request = WebRequest.Create (url) as HttpWebRequest;

        request.Method = method;

        request.Accept = "text/javascript, text/html, application/xml, text/xml, */*";
        request.ContentType = "application/x-www-form-urlencoded; charset=UTF-8";
        request.Host = "steamcommunity.com";
        request.UserAgent = "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/536.11 (KHTML, like Gecko) Chrome/20.0.1132.47 Safari/536.11";
        request.Referer = "http://steamcommunity.com/trade/1";

        if (ajax)
        {
            request.Headers.Add ("X-Requested-With", "XMLHttpRequest");
            request.Headers.Add ("X-Prototype-Version", "1.7");
        }

        // Cookies
        request.CookieContainer = cookies ?? new CookieContainer ();

        // Request data
        if (data != null)
        {
            string dataString = String.Join ("&", Array.ConvertAll (data.AllKeys, key =>
                String.Format ("{0}={1}", HttpUtility.UrlEncode (key), HttpUtility.UrlEncode (data [key]))
            )
            );

            byte[] dataBytes = Encoding.ASCII.GetBytes (dataString);
            request.ContentLength = dataBytes.Length;

            Stream requestStream = request.GetRequestStream ();
            requestStream.Write (dataBytes, 0, dataBytes.Length);
        }

        // Get the response
        //return request.GetResponse () as HttpWebResponse;

        //EXCEPTION8712905

        double millisecondsDelay = 2000;//10
        //double delayMultiplyFactor = 2;
        int allowedRetries = 10000;//10

        while (true)
        {
            try
            {
                return request.GetResponse() as HttpWebResponse;
            }
            catch (Exception e)
            {
                if (e is WebException && allowedRetries-- > 0)
                {
                    System.Console.WriteLine("Trying to Reconnect...");
                    Thread.Sleep((int)millisecondsDelay);
                    //millisecondsDelay *= delayMultiplyFactor;
                }
                else
                {
                    throw;
                }
            }
        }
    }

回程充当一个中断,中断是不必要的。使用这样的接球挡也是个坏主意。仅捕获您知道如何处理的特定异常。Thz.:)我要让它整夜运行。。我们要睡觉了P明天见顺便问一下,我如何添加所有4个可能的异常?可以肯定的是P-WebException-InvalidOperationException-NotSupportedException和-ProtocolViolationException是否正确?如果((e是WebException | | e是InvalidOperationException | | e是NotSupportedException | | | e是ProtocolViolationException)&&allowedRetries-->0)@user3712882:是的,尽管我建议将其重构为布尔方法。您也可以参考此Microsoft示例: