Question

我写完这篇文章的人离开公司之后，我继承了一些代码。显然它从未奏效，但我不知道为什么。

它正试图从台湾证券交易所网站下载包含外汇汇率的CSV文件。

网址为

http://rate.bot.com.tw/Pages/UIP004/Download0042.ashx?lang=en-US&fileType=1&afterOrNot=0&whom=SGD&date1=20110401&date2=20110430

如果我将该网址直接粘贴到Internet Explorer中，我会立即收到回复，询问我是否要打开或保存该文件，我可以打开并保存该文件没有任何问题。

当我运行C＃代码获取文件时，我在大约90秒后收到错误消息“操作已超时”。我尝试将超时时间更改为3分钟，以防需要更长时间，但仍然没有运气。我可以看到在本地创建的空文件，但没有任何内容被填充到其中。

private static void GetVendorFiles(String sUrl, String sFileNameToWrite, String sProxy)
{
    DateTime dtStart = System.DateTime.Now;

    using (CertWebClient client = new CertWebClient())

    try
    {
        WebProxy proxy = new WebProxy(sProxy);
        proxy.Credentials = CredentialCache.DefaultCredentials;
        WebRequest.DefaultWebProxy = proxy;

        //Override the default policy of System.Net not accepting self-signed certificates
        System.Net.ServicePointManager.ServerCertificateValidationCallback
         = CertificatePolicy.ValidateSSLCertificate;

        //Download file and write to network drive
        client.DownloadFile(sUrl, sFileNameToWrite);

        proxy = null;

    }
    catch (Exception ex)
    {
        Console.WriteLine(ex.Message); 
        TraceHelper.WriteLine("PathHelper.DownLoadFiles:" + ex.Message);
        throw;
    }
}

我尝试了两种不同的ContentType值 - “text / plain”和“application / octet-stream”。没有任何区别。

class CertWebClient : WebClient      
{
    protected override WebRequest GetWebRequest(Uri address) 
    {

        try
        {
            HttpWebRequest request = (HttpWebRequest)base.GetWebRequest(address);
            request.ContentType = "application/octet-stream";
            return request;
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message); 
            TraceHelper.WriteLine("Taiwan FX Rates Web Certificate Error:" + ex.Message);
            throw;
        }
    }

    public static void Getcert(string certLocation,string sPassword)
    {

        if (certLocation == "")
        {
            throw new ArgumentException ("Null certificate location passed to CertWebClient");
        }

        if (sPassword == "")
        {
            throw new ArgumentException("Null password passed to CertWebClient");
        }
        certificateLocation = certLocation;
        certPassword = sPassword;   
    }

    private static string certificateLocation;
    private static string certPassword;
}

任何帮助将不胜感激

Answer 1

设置以下属性：

request.Method = "GET";
request.UserAgent = "Mozilla/5.0 (Windows NT 6.2; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/32.0.1667.0 Safari/537.36"
request.KeepAlive = true;
request.Timeout = Timeout.Infinite;

这应该有用。

httpwebrequest超时错误c＃

1 个答案: