Amazon.S3.Util.S3PostUploadRequest.WriteFormData C# (CSharp) Method

        internal void WriteFormData(string boundary, Stream outputStream)
        {
            if (!String.IsNullOrEmpty(this.Key))
                WriteFormDatum(outputStream, S3Constants.PostFormDataObjectKey, this.Key, boundary);

            WriteFormDatum(outputStream, S3Constants.PostFormDataAcl, this.CannedACL, boundary);

            if (this._isSetStorageClass)
                WriteFormDatum(outputStream, S3Constants.AmzStorageClassHeader, this.StorageClass, boundary);

            if (this._isSetActionStatus)
                WriteFormDatum(outputStream, S3Constants.PostFormDataStatus, ((Int32)this.SuccessActionStatus).ToString(CultureInfo.InvariantCulture), boundary);

            if (!String.IsNullOrEmpty(this.SuccessActionRedirect))
                WriteFormDatum(outputStream, S3Constants.PostFormDataRedirect, this.SuccessActionRedirect, boundary);

            if (String.IsNullOrEmpty(this.ContentType))
            {
                if (this.Key.IndexOf('.') > -1)
                    this.ContentType = AmazonS3Util.MimeTypeFromExtension(this.Key.Substring(this.Key.LastIndexOf('.')));
                else if (!String.IsNullOrEmpty(this.Path) && this.Path.IndexOf('.') > -1)
                    this.ContentType = AmazonS3Util.MimeTypeFromExtension(this.Key.Substring(this.Path.LastIndexOf('.')));
            }

            WriteFormDatum(outputStream, S3Constants.PostFormDataContentType, this.ContentType, boundary);

            foreach (var kvp in this.Metadata)
            {
                var metakey = kvp.Key.StartsWith(S3Constants.PostFormDataXAmzPrefix, StringComparison.Ordinal) ? kvp.Key : S3Constants.PostFormDataMetaPrefix + kvp.Key;
                WriteFormDatum(outputStream, metakey, kvp.Value, boundary);
            }

            if (this.SignedPolicy != null)
            {
                WriteFormDatum(outputStream, S3Constants.PostFormDataAccessKeyId, this.SignedPolicy.AccessKeyId, boundary);
                WriteFormDatum(outputStream, S3Constants.PostFormDataPolicy, this.SignedPolicy.Policy, boundary);
                WriteFormDatum(outputStream, S3Constants.PostFormDataSignature, this.SignedPolicy.Signature, boundary);
            }
        }

        /// <summary>
        /// Upload data to Amazon S3 using HTTP POST.
        /// </summary>
        /// <remarks>
        /// For more information, <see href="http://docs.aws.amazon.com/AmazonS3/latest/dev/UsingHTTPPOST.html"/>
        /// </remarks>
        /// <param name="request">Request object which describes the data to POST</param>
        /// <exception cref="S3PostUploadException">Thrown if the service returns an error</exception>
        public static S3PostUploadResponse PostUpload(S3PostUploadRequest request)
        {
            string url;
            string subdomain = request.Region.Equals(RegionEndpoint.USEast1) ? "s3" : "s3-" + request.Region.SystemName;

            if (request.Bucket.IndexOf('.') > -1)
            {
                url = string.Format(CultureInfo.InvariantCulture, "https://{0}.amazonaws.com/{1}/", subdomain, request.Bucket);
            }
            else
            {
                url = string.Format(CultureInfo.InvariantCulture, "https://{0}.{1}.amazonaws.com", request.Bucket, subdomain);
            }
            Uri uri = new Uri(url);

            HttpWebRequest webRequest = WebRequest.Create(uri) as HttpWebRequest;

            var boundary = Convert.ToBase64String(Guid.NewGuid().ToByteArray()).Replace('=', 'z');

            webRequest.ContentType = string.Format(CultureInfo.InvariantCulture, "multipart/form-data; boundary={0}", boundary);
            webRequest.Method      = "POST";

            using (var reqStream = webRequest.GetRequestStream())
            {
                request.WriteFormData(boundary, reqStream);

                byte[] boundaryBytes = Encoding.UTF8.GetBytes(string.Format(CultureInfo.InvariantCulture, "--{0}\r\nContent-Disposition: form-data; name=\"file\"\r\n\r\n", boundary));

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

                using (var inputStream = null == request.Path ? request.InputStream : File.OpenRead(request.Path))
                {
                    byte[] buf = new byte[1024];
                    int    bytesRead;
                    while ((bytesRead = inputStream.Read(buf, 0, 1024)) > 0)
                    {
                        reqStream.Write(buf, 0, bytesRead);
                    }
                }

                byte[] endBoundaryBytes = Encoding.UTF8.GetBytes(string.Format(CultureInfo.InvariantCulture, "\r\n--{0}--", boundary));

                reqStream.Write(endBoundaryBytes, 0, endBoundaryBytes.Length);
            }

            HttpWebResponse response = null;

            try
            {
                response = webRequest.GetResponse() as HttpWebResponse;
            }
            catch (WebException ex)
            {
                throw S3PostUploadException.FromResponse((HttpWebResponse)ex.Response);
            }

            return(S3PostUploadResponse.FromWebResponse(response));
        }