/// <summary>
/// 將本地文件上傳到指定的服務(wù)器(HttpWebRequest方法)
/// </summary>
/// <param name="address">文件上傳到的服務(wù)器</param>
/// <param name="fileNamePath">要上傳的本地文件（全路徑）</param>
/// <param name="saveName">文件上傳后的名稱</param>
/// <param name="progressBar">上傳進(jìn)度條</param>
/// <returns>成功返回1，失敗返回0</returns>
private int Upload_Request(string address, string fileNamePath, string saveName, ProgressBar progressBar)
{
    int returnValue = 0;

    // 要上傳的文件
    FileStream fs = new FileStream(fileNamePath, FileMode.Open, FileAccess.Read);
    BinaryReader r = new BinaryReader(fs);

    //時間戳
    string strBoundary = "----------" + DateTime.Now.Ticks.ToString("x");
    byte[] boundaryBytes = Encoding.ASCII.GetBytes("\r\n--" + strBoundary + "\r\n");

    //請求頭部信息
    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);

    // 根據(jù)uri創(chuàng)建HttpWebRequest對象
    HttpWebRequest httpReq = (HttpWebRequest)WebRequest.Create(new Uri(address));
    httpReq.Method = "POST";

    //對發(fā)送的數(shù)據(jù)不使用緩存
    httpReq.AllowWriteStreamBuffering = false;

    //設(shè)置獲得響應(yīng)的超時時間（默認(rèn)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;

        //每次上傳4k
        int bufferLength = 4096;
        byte[] buffer = new byte[bufferLength];

        //已上傳的字節(jié)數(shù)
        long offset = 0;

        //開始上傳時間
        DateTime startTime = DateTime.Now;
        int size = r.Read(buffer, 0, bufferLength);
        Stream postStream = httpReq.GetRequestStream();

        //發(fā)送請求頭部消息
        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 = "已用時：" + 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 = " 正在連接…";
            }
            lblState.Text = "已上傳：" + (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);
        }
        //添加尾部的時間戳
        postStream.Write(boundaryBytes, 0, boundaryBytes.Length);
        postStream.Close();

        //獲取服務(wù)器端的響應(yīng)
        WebResponse webRespon = httpReq.GetResponse();
        Stream s = webRespon.GetResponseStream();
        StreamReader sr = new StreamReader(s);

        //讀取服務(wù)器端返回的消息
        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;
}

參數(shù)說明如下：

address：接收文件的URL地址，如：http://localhost/UploadFile/Save.aspx

fileNamePath：要上傳的本地文件，如：D:\test.rar

saveName：文件上傳到服務(wù)器后的名稱，如：200901011234.rar

progressBar：顯示文件上傳進(jìn)度的進(jìn)度條。

接收文件的WebForm添加一個Save.aspx頁面，Load方法如下：

protected void Page_Load(object sender, EventArgs e)
{
    if (Request.Files.Count > 0)
    {
        try
        {
            HttpPostedFile file = Request.Files[0];
            string filePath = this.MapPath("UploadDocument") + "\" + file.FileName;
            file.SaveAs(filePath);
            Response.Write("Success\r\n");
        }
        catch
        {
            Response.Write("Error\r\n");
        }
    }
}

同時需要配置WebConfig文件的httpRuntime 如下：

<httpRuntime maxRequestLength="102400" executionTimeout="300"/>

不能的話最大只能上傳4M了。要是想上傳更大的文件，maxRequestLength，executionTimeout設(shè)置大些，同時WinForm下的代碼行

//設(shè)置獲得響應(yīng)的超時時間（300秒）
httpReq.Timeout = 300000;