c# - 无法读取 XML 数据

Question

我想从远程服务器读取 xml 文件，但不知何故服务器没有响应我的请求。因此，Gzip 会抛出“GZip 标头中的幻数不正确”异常。任何想法？

 private static string GetFile()
    {
        Uri uri = new Uri(@"http://www.iddaa.com.tr/XML/IDDAAMACPROGRAMI/index.htm?iddaadrawid=12.09.2012&iddaadrawide=13.09.2012&foraccess=KSsec654");

        string xmlFile;

        HttpWebRequest req = (HttpWebRequest) HttpWebRequest.Create(uri);
        req.UserAgent =
            "MOZILLA/5.0 (WINDOWS NT 6.1; WOW64) APPLEWEBKIT/537.1 (KHTML, LIKE GECKO) CHROME/21.0.1180.75 SAFARI/537.1";
        req.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
        req.Headers.Add("Accept-Encoding", "gzip,deflate");


        using (GZipStream zip = new GZipStream(req.GetResponse().GetResponseStream(),
                                               CompressionMode.Decompress))
        {
            var reader = new StreamReader(zip);
            xmlFile = reader.ReadToEnd();
        }

        return xmlFile;
    }

Answer 1

您不需要使用 gzip。HttpWebRequest如果服务器将 gzip 标头发送到响应，它将自动为您执行此操作。

但是您甚至可以使用WebClient进一步简化您的代码：

private static string GetFile()
{
    using (var client = new WebClient())
    {
        client.Headers[HttpRequestHeader.UserAgent] = "MOZILLA/5.0 (WINDOWS NT 6.1; WOW64) APPLEWEBKIT/537.1 (KHTML, LIKE GECKO) CHROME/21.0.1180.75 SAFARI/537.1";
        client.Headers[HttpRequestHeader.Accept] = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
        client.Headers[HttpRequestHeader.AcceptEncoding] = "gzip,deflate";
        var xmlFile = client.DownloadString("http://www.iddaa.com.tr/XML/IDDAAMACPROGRAMI/index.htm?iddaadrawid=12.09.2012&iddaadrawide=13.09.2012&foraccess=KSsec654");
        return xmlFile;
    }
}

或 .NET 4.5 中引入的新HttpClient类：

private async Task<string> GetFile()
{
    using (var client = new HttpClient() { BaseAddress = new Uri("http://www.iddaa.com.tr") })
    {
        client.DefaultRequestHeaders.UserAgent.Add(new ProductInfoHeaderValue("MOZILLA", "5.0"));
        client.DefaultRequestHeaders.UserAgent.Add(new ProductInfoHeaderValue("(WINDOWS NT 6.1; WOW64)"));
        client.DefaultRequestHeaders.UserAgent.Add(new ProductInfoHeaderValue("APPLEWEBKIT", "537.1"));
        client.DefaultRequestHeaders.UserAgent.Add(new ProductInfoHeaderValue("(KHTML, LIKE GECKO)"));
        client.DefaultRequestHeaders.UserAgent.Add(new ProductInfoHeaderValue("CHROME", "21.0.1180.75"));
        client.DefaultRequestHeaders.UserAgent.Add(new ProductInfoHeaderValue("SAFARI", "537.1"));

        client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("text/html"));
        client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/xhtml+xml"));
        client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/xml", 0.9));
        client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("*/*", 0.8));

        client.DefaultRequestHeaders.AcceptEncoding.Add(new StringWithQualityHeaderValue("gzip"));
        client.DefaultRequestHeaders.AcceptEncoding.Add(new StringWithQualityHeaderValue("deflate"));
        var result = await client.GetAsync("/XML/IDDAAMACPROGRAMI/index.htm?iddaadrawid=12.09.2012&iddaadrawide=13.09.2012&foraccess=KSsec654");
        result.EnsureSuccessStatusCode();
        return await result.Content.ReadAsStringAsync();
    }
}