c#ASP HttpWebRequest多部分上传XML和图像

我已经（尝试）定制了一个在Stackoverflow上找到的方法，以支持一个XML文件和多个图像的多部分上传，从而将HTTPWebRequest处理成Sharepoint Web部件。遗憾的是，我不得不说，我真的不熟悉HttpRequest和StreamUpload这件事，这是我第一次认真处理这件事

这是我的代码：

    public XmlDocument DoHttpUploadFile(string url, string[] file, string[] paramName, string[] contentType, NameValueCollection nvc, NameValueCollection headerItems, string xmlFileName)
    {
        var xmlDox = new XmlDocument();
        var totalLength = 0;
        string boundary = "---------------------------" + DateTime.Now.Ticks.ToString("x");
        byte[] boundarybytes = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "\r\n");
        const string headerTemplate = "Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"\r\nContent-Type: {2}\r\n\r\n";

        // First Loop is just need to get the Length of all Parts

        for (int i = 0; i < file.Length; i++)
        {
            string header = "";
            if (i == 0)
            {
                header = string.Format(headerTemplate, paramName[i], xmlFileName, contentType[i]);
            }
            else
            {
                var filename = Path.GetFileName(file[i]);
                header = string.Format(headerTemplate, paramName[i], filename, contentType[i]);
            }

            byte[] headerbytes = System.Text.Encoding.UTF8.GetBytes(header);

            var headerLength = headerbytes.Length;
            var boundaryLength = boundarybytes.Length;

            totalLength = totalLength + headerLength + boundaryLength;

            if (file[i].StartsWith("<"))
            {
                byte[] xmlBytes = System.Text.Encoding.UTF8.GetBytes(file[i]);
                var xmlLength = xmlBytes.Length;
                totalLength = totalLength + xmlLength;
            }
            else
            {
                var client = new WebClient();
                var img = new Image { ImageUrl = file[i] };

                client.UseDefaultCredentials = true;
                // image as Byte into Stream
                var fileData = client.DownloadData(img.ImageUrl);
                var imgLength = fileData.Length;
                totalLength = totalLength + imgLength;
            }
        }

        var wr = (HttpWebRequest)WebRequest.Create(url);

        wr.ContentType = "multipart/form-data; boundary=" + boundary;
        wr.Method = "POST";
        wr.ContentLength = totalLength;

        Stream rs = wr.GetRequestStream();
        var read = 0;
        var finalLength = 0;

        for (int i = 0; i < file.Length; i++)
        {
            string header = "";
            if(i==0)
            {
                header = string.Format(headerTemplate, paramName[i], xmlFileName, contentType[i]);
            }
            else
            {
                var filename = Path.GetFileName(file[i]);
                header = string.Format(headerTemplate, paramName[i], filename, contentType[i]);
            }

            rs.Write(boundarybytes, 0, boundarybytes.Length);

            byte[] headerbytes = System.Text.Encoding.UTF8.GetBytes(header);

            var headerLength = headerbytes.Length;
            var boundaryLength = boundarybytes.Length;
            finalLength = finalLength + headerLength + boundaryLength;
            rs.Write(headerbytes, 0, headerbytes.Length);

            if(file[i].StartsWith("<"))
            {
                var writer = new StreamWriter(rs);
                byte[] xmlBytes = System.Text.Encoding.UTF8.GetBytes(file[i]);
                var xmlLength = xmlBytes.Length;
                finalLength = finalLength + xmlLength;
                writer.Write(file[i]);
            }
            else
            {
                var getitem = new GetItemFromList();

                var client = new WebClient();
                var img = new Image {ImageUrl = file[i]};

                client.UseDefaultCredentials = true;
                // image as Byte into Stream
                var fileData = client.DownloadData(img.ImageUrl);
                finalLength = finalLength + fileData.Length;
                rs.Write(fileData, 0, fileData.Length);
            }

        }

        finalLength.ToString();
rs.Close(); // Here it stops with Exception 'Bytes are not completely written



        WebResponse wresp = null;
        try
        {
            wresp = wr.GetResponse();
            var wrlength = wr.ContentLength;
            var stream2 = wresp.GetResponseStream();
            if (stream2 != null)
            {
                var reader2 = new StreamReader(stream2);
                var backstr = reader2.ReadToEnd();

                xmlDox.LoadXml(backstr);
            }
        }
        catch (Exception ex)
        {
            //log.Error("Error uploading file", ex);
            if (wresp != null) 
                wresp.Close();
            wresp = null;
        }
        finally
        {
            wr = null;            }

        return xmlDox;
    }

public-XmlDocument-DoHttpUploadFile（字符串url、字符串[]文件、字符串[]参数名、字符串[]内容类型、NameValueCollection-nvc、NameValueCollection-headerItems、字符串xmlFileName）
{
var xmlDox=新的XmlDocument（）；
var总长度=0；
字符串边界=“------------------------------------”+DateTime.Now.Ticks.ToString（“x”）；
byte[]boundarybytes=System.Text.Encoding.ASCII.GetBytes（“\r\n--”+boundary+”\r\n”）；
const string headerTemplate=“内容处置：表单数据；名称=\”{0}\“文件名=\“{1}\”\r\n内容类型：{2}\r\n\r\n”；
//第一个循环只需要得到所有零件的长度
for（int i=0；i
见此帖：

您能否检查TotalLength的大小，确保使用字节长度并在调试器中进行验证