/// <summary>
/// 文件上传至远程服务器
/// </summary>
/// <param name="url">远程服务地址</param>
/// <param name="postedFile">上传文件</param>
/// <param name="parameters">POST参数</param>
/// <param name="cookieContainer">cookie</param>
/// <param name="output">远程服务器响应字符串</param>
public static void HttpPostFile(string url,
System.Web.HttpPostedFile postedFile,
Dictionary<string, object> parameters,
CookieContainer cookieContainer,
ref string output)
{
//1>创建请求
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
//2>Cookie容器
request.CookieContainer = cookieContainer;
request.Method = "POST";
request.Timeout = ;
request.Credentials = System.Net.CredentialCache.DefaultCredentials;
request.KeepAlive = true; string boundary = "----------------------------" + DateTime.Now.Ticks.ToString("x");//分界线
byte[] boundaryBytes = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "\r\n"); request.ContentType = "multipart/form-data; boundary=" + boundary; ;//内容类型 //3>表单数据模板
string formdataTemplate = "\r\n--" + boundary + "\r\nContent-Disposition: form-data; name=\"{0}\";\r\n\r\n{1}"; //4>读取流
byte[] buffer = new byte[postedFile.ContentLength];
postedFile.InputStream.Read(buffer, , buffer.Length); //5>写入请求流数据
string strHeader = "Content-Disposition:application/x-www-form-urlencoded; name=\"{0}\";filename=\"{1}\"\r\nContent-Type:{2}\r\n\r\n";
strHeader = string.Format(strHeader,
"filedata",
postedFile.FileName,
postedFile.ContentType);
//6>HTTP请求头
byte[] byteHeader = System.Text.ASCIIEncoding.ASCII.GetBytes(strHeader);
try
{
using (Stream stream = request.GetRequestStream())
{
//写入请求流
if (null != parameters)
{
foreach (KeyValuePair<string, object> item in parameters)
{
stream.Write(boundaryBytes, , boundaryBytes.Length);//写入分界线
byte[] formBytes = System.Text.Encoding.UTF8.GetBytes(string.Format(formdataTemplate, item.Key, item.Value));
stream.Write(formBytes, , formBytes.Length);
}
}
//6.0>分界线============================================注意：缺少次步骤，可能导致远程服务器无法获取Request.Files集合
stream.Write(boundaryBytes, , boundaryBytes.Length);
//6.1>请求头
stream.Write(byteHeader, , byteHeader.Length);
//6.2>把文件流写入请求流
stream.Write(buffer, , buffer.Length);
//6.3>写入分隔流
byte[] trailer = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "--\r\n");
stream.Write(trailer, , trailer.Length);
//6.4>关闭流
stream.Close();
}
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
using (StreamReader reader = new StreamReader(response.GetResponseStream()))
{
output = reader.ReadToEnd();
}
response.Close();
}
catch (Exception ex)
{
throw new Exception("上传文件时远程服务器发生异常！", ex);
}
}