HttpWebRequest 使用NetworkCredential 进行域认证下载时不成功 的解决方案

最近在项目中使用pWebRequest 使用NetworkCredential 进行域认证下载时老不成功，最后Google了解决方案，发现几乎所有讨论的方案都不成功，只好埋头自己解决，最后总算调试通过，特将整个解决过程的代码实现记录下来，节约大家以后解决类似问题的时间。



KEY POINT: 主要是需要加入ContentType让Server端能够正确解码。

request.ContentType = "application/x-www-form-urlencoded";



具体实现代码如下：



void DownloadOneFileByHttp(string remoteurl, string localpath, string localurl)

{

HttpWebRequest

request = HttpWebRequest.Create(remoteurl) as HttpWebRequest; WebRequestMethods.Http.Get; false; new NetworkCredential(this.UserName, this.Password, this.Domain); "application/x-www-form-urlencoded"; //very important for authentication

request.Method =

request.PreAuthenticate =

request.Credentials =

request.ContentType =



MemoryStream memStream = new MemoryStream(1024 * 500);


byte[] buffer = new byte[1024];
HttpWebResponse response = request.GetResponse() as HttpWebResponse;


Stream reader = response.GetResponseStream();



// Create the subfolder


if (!System.IO.File.Exists(localpath))
{

System.IO.

Directory.CreateDirectory(localpath);

}



// Write specified bytes array (content) to a file

FileStream newFile = null;


try

{

newFile =

new FileStream(localurl, FileMode.Create);



while (true)
{

int bytesRead = reader.Read(buffer, 0, buffer.Length);



if(bytesRead == 0)
{

break;
}



else

{

memStream.Write(buffer, 0, bytesRead);
}

}



if(memStream.Length > 0)
{

// Converts the downloaded stream to a byte array

byte [] downloadedData = memStream.ToArray();
newFile.Write(downloadedData, 0, downloadedData.Length);

}

}



catch (Exception ex)
{

System.

Console.WriteLine("Exception in HTTP downloading: {0}", ex.Message);
}

finally

{



if (newFile != null) newFile.Close();


if (reader != null) reader.Close();


if (response != null) response.Close();


}

}



最后提示一下大家：对于想了解为何要这样写的朋友可以使用IE登陆并且用httpwatchpro 拦截一下整个报文的内容，然后用.NET代码访问并且下载同样的文件，然后使用winpcap这样的网络嗅探器拦截一下整个报文的内容，对比一下你就很容易得出结论。



当然这个解决方案对于熟知HTTP协议并且编写过自定义爬虫的朋友是很容易得出。