C#从src下载图片，不带扩展名

Question

我想从这个网址http://squirlytraffic.com/surficon.php?ts=1491591235下载一张图片

我尝试了此代码，但打开它时看不到图像。

using (WebClient client = new WebClient())
  {
    client.DownloadFile("http://squirlytraffic.com/surficon.php?ts=1491591235", @"D:\image.jpg");         
  }

Answer 1

您需要使用 WebClient Credentials 属性设置您的凭据。您可以通过为其分配NetworkCredential 的实例来完成此操作。见下文：

using (WebClient client = new WebClient()){
  client.Credentials = new NetworkCredential("user-name", "password");
  client.DownloadFile("url", @"file-location");
}

编辑

如果您不想硬编码用户名和密码，可以将 WebClient 的 UseDefaultCredentials 属性设置为 true。这将使用当前登录用户的凭据。来自documentation。

Credentials 属性包含用于访问主机上资源的身份验证凭据。在大多数客户端场景中，您应该使用 DefaultCredentials，它是当前登录用户的凭据。为此，请将 UseDefaultCredentials 属性设置为 true，而不是设置此属性。

这意味着您可以将上述代码修改为：

using (WebClient client = new WebClient()){
  client.UseDefaultCredentials = true;
  client.DownloadFile("url", @"file-location");
}

Answer 2

试试这个方法，登录的时候传那些参数

            StringBuilder postData = new StringBuilder();
            postData.Append("login=" + HttpUtility.UrlEncode("username") + "&");
            postData.Append("password=" + HttpUtility.UrlEncode("password") + "&");
            postData.Append("Submit=" + HttpUtility.UrlEncode("Login"));
            ASCIIEncoding ascii = new ASCIIEncoding();
            byte[] postBytes = ascii.GetBytes(postData.ToString());
            CookieContainer cc = new CookieContainer();
            HttpWebRequest webReq = (HttpWebRequest)WebRequest.Create("http://squirlytraffic.com/members.php");
            webReq.Method = "POST";
            webReq.ContentType = "application/x-www-form-urlencoded";
            webReq.ContentLength = postBytes.Length;
            webReq.UserAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.1.4322; .NET CLR 2.0.50727)";
            webReq.CookieContainer = cc;
            Stream postStream = webReq.GetRequestStream();
            postStream.Write(postBytes, 0, postBytes.Length);
            postStream.Flush();
            postStream.Close();
            HttpWebResponse res = (HttpWebResponse)webReq.GetResponse();
            HttpWebRequest ImgReq = (HttpWebRequest)WebRequest.Create("http://squirlytraffic.com/surficon.php?ts=1491591235");
            ImgReq.Method = "GET";
            ImgReq.UserAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.1.4322; .NET CLR 2.0.50727)";
            ImgReq.CookieContainer = cc;
            HttpWebResponse ImgRes = (HttpWebResponse)ImgReq.GetResponse();
            Stream Img = ImgRes.GetResponseStream();