c#上传大文件方法

/// <summary>

/// 将本地文件上传到指定的服务器(HttpWebRequest方法)

/// </summary>

/// <param name="address">文件上传到的服务器</param>

/// <param name="fileNamePath">要上传的本地文件（全路径）</param>

/// <param name="saveName">文件上传后的名称</param>

/// <returns>服务器反馈信息</returns>

private string Upload_Request(string address, string fileNamePath, string saveName)
{

// 要上传的文件

FileStream fs = new FileStream(fileNamePath, FileMode.Open, FileAccess.Read);

BinaryReader r = new BinaryReader(fs);

//时间戳

string strBoundary = "----------" + DateTime.Now.Ticks.ToString("x");

byte[] boundaryBytes = Encoding.ASCII.GetBytes("\r\n--" + strBoundary + "\r\n");

//请求头部信息

StringBuilder sb = new StringBuilder();

sb.Append("--");

sb.Append(strBoundary);

sb.Append("\r\n");

sb.Append("Content-Disposition: form-data; name=\"");

sb.Append("file");

sb.Append("\"; filename=\"");

sb.Append(saveName);

sb.Append("\"");

sb.Append("\r\n");

sb.Append("Content-Type: ");

sb.Append("application/octet-stream");

sb.Append("\r\n");

sb.Append("\r\n");

string strPostHeader = sb.ToString();

byte[] postHeaderBytes = Encoding.UTF8.GetBytes(strPostHeader);

// 根据uri创建HttpWebRequest对象

HttpWebRequest httpReq = (HttpWebRequest)WebRequest.Create(new Uri(address));

httpReq.Method = "POST";

//对发送的数据不使用缓存【重要、关键】

httpReq.AllowWriteStreamBuffering = false;

//设置获得响应的超时时间（300秒）

//httpReq.Timeout = 300000;

httpReq.ContentType = "multipart/form-data; boundary=" + strBoundary;

long length = fs.Length + postHeaderBytes.Length + boundaryBytes.Length;

long fileLength = fs.Length;

httpReq.ContentLength = length;

try
{
//每次上传4k

int bufferLength = 4096;

byte[] buffer = new byte[bufferLength];

//已上传的字节数

long offset = 0;

//开始上传时间

DateTime startTime = DateTime.Now;

int size = r.Read(buffer, 0, bufferLength);

Stream postStream = httpReq.GetRequestStream();

//发送请求头部消息

postStream.Write(postHeaderBytes, 0, postHeaderBytes.Length);

while (size > 0)
{

postStream.Write(buffer, 0, size);

offset += size;

TimeSpan span = DateTime.Now - startTime;
//1024*1024=1048576
size = r.Read(buffer, 0, bufferLength);

}

//添加尾部的时间戳

postStream.Write(boundaryBytes, 0, boundaryBytes.Length);

postStream.Close();

//获取服务器端的响应

WebResponse webRespon = httpReq.GetResponse();

Stream s = webRespon.GetResponseStream();

StreamReader sr = new StreamReader(s);

//读取服务器端返回的消息

string serverMsg = sr.ReadLine();
s.Close();

sr.Close();

}

catch (Exception ex)
{

}

finally
{

fs.Close();

r.Close();

}

return "";

}

HttpPostedFileBase file = Request.Files[0];
file.SaveAs(Server.MapPath("~/file/k.iso"));