首先写客服端，winform模拟一个post提交：
/// <summary>参数说明如下： address：接收文件的URL地址，如：http://localhost/UploadFile/Save.aspx fileNamePath：要上传的本地文件，如：D:\test.rar saveName：文件上传到服务器后的名称，如：200901011234.rar progressBar：显示文件上传进度的进度条。 接收文件的WebForm添加一个Save.aspx页面，Load方法如下：
/// 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>
/// <param name="progressBar">上传进度条</param>
/// <returns>成功返回1，失败返回0</returns>
private int Upload_Request2(string address, string fileNamePath, string saveName, ProgressBar progressBar)
{
int returnValue = 0; // 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
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
{
progressBar.Maximum = int.MaxValue;
progressBar.Minimum = 0;
progressBar.Value = 0;
//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;
progressBar.Value = (int)(offset * (int.MaxValue / length));
TimeSpan span = DateTime.Now - startTime;
double second = span.TotalSeconds;
lblTime.Text = "已用时：" + second.ToString("F2") + "秒";
if (second > 0.001)
{
lblSpeed.Text = "平均速度：" + (offset / 1024 / second).ToString("0.00") + "KB/秒";
}
else
{
lblSpeed.Text = " 正在连接…";
}
lblState.Text = "已上传：" + (offset * 100.0 / length).ToString("F2") + "%";
lblSize.Text = (offset / 1048576.0).ToString("F2") + "M/" + (fileLength / 1048576.0).ToString("F2") + "M";
Application.DoEvents();
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();
//读取服务器端返回的消息
StreamReader sr = new StreamReader(s);
String sReturnString = sr.ReadLine();
s.Close();
sr.Close();
if (sReturnString == "Success")
{
returnValue = 1;
}
else if (sReturnString == "Error")
{
returnValue = 0;
}
}
catch
{
returnValue = 0;
}
finally
{
fs.Close();
r.Close();
} return returnValue;
}
protected void Page_Load(object sender, EventArgs e)同时需要配置WebConfig文件的httpRuntime 如下： <httpRuntime maxRequestLength="102400" executionTimeout="300"/> 不能的话最大只能上传4M了。要是想上传更大的文件，maxRequestLength，executionTimeout设置大些，同时WinForm下的代码行 //设置获得响应的超时时间（300秒）
{
if (Request.Files.Count > 0)
{
try
{
HttpPostedFile file = Request.Files[0];
//string filePath = "C:\\Documents and Settings\\Administrator\\桌面\\2\\" + file.FileName;//this.MapPath("UploadDocument")
string filePath = "D:\\SourceSafe\\testupform\\" + file.FileName;
file.SaveAs(filePath);
Response.Write("Success");
}
catch
{
Response.Write("Error");
}
}
else
{
Response.Write("Error1");
}
}
httpReq.Timeout = 300000;
也要修改，另外别忘了看看IIS的连接超时是否设置为足够大。