Cargar archivos con HTTPWebrequest (multipart / form-data)

¿Hay alguna clase, biblioteca o algún código que me ayude a cargar archivos con HTTPWebrequest ?

Editar 2:

No quiero subir a una carpeta WebDAV o algo así. Quiero simular un navegador, así como subir tu avatar a un foro o subir un archivo a través del formulario en una aplicación web. Cargar en un formulario que utiliza un multipart / form-data.

Editar:

WebClient no cubre mis requisitos, entonces estoy buscando una solución con HTTPWebrequest .

Tomó el código anterior y lo arregló porque arroja el error 500 del servidor interno. Hay algunos problemas con \ r \ n mal posicionados y espacios, etc. Se aplicó la refactorización con flujo de memoria, escribiendo directamente en la secuencia de solicitud. Aquí está el resultado:

public static void HttpUploadFile(string url, string file, string paramName, string contentType, NameValueCollection nvc) { log.Debug(string.Format("Uploading {0} to {1}", file, url)); string boundary = "---------------------------" + DateTime.Now.Ticks.ToString("x"); byte[] boundarybytes = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "\r\n"); HttpWebRequest wr = (HttpWebRequest)WebRequest.Create(url); wr.ContentType = "multipart/form-data; boundary=" + boundary; wr.Method = "POST"; wr.KeepAlive = true; wr.Credentials = System.Net.CredentialCache.DefaultCredentials; Stream rs = wr.GetRequestStream(); string formdataTemplate = "Content-Disposition: form-data; name=\"{0}\"\r\n\r\n{1}"; foreach (string key in nvc.Keys) { rs.Write(boundarybytes, 0, boundarybytes.Length); string formitem = string.Format(formdataTemplate, key, nvc[key]); byte[] formitembytes = System.Text.Encoding.UTF8.GetBytes(formitem); rs.Write(formitembytes, 0, formitembytes.Length); } rs.Write(boundarybytes, 0, boundarybytes.Length); string headerTemplate = "Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"\r\nContent-Type: {2}\r\n\r\n"; string header = string.Format(headerTemplate, paramName, file, contentType); byte[] headerbytes = System.Text.Encoding.UTF8.GetBytes(header); rs.Write(headerbytes, 0, headerbytes.Length); FileStream fileStream = new FileStream(file, FileMode.Open, FileAccess.Read); byte[] buffer = new byte[4096]; int bytesRead = 0; while ((bytesRead = fileStream.Read(buffer, 0, buffer.Length)) != 0) { rs.Write(buffer, 0, bytesRead); } fileStream.Close(); byte[] trailer = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "--\r\n"); rs.Write(trailer, 0, trailer.Length); rs.Close(); WebResponse wresp = null; try { wresp = wr.GetResponse(); Stream stream2 = wresp.GetResponseStream(); StreamReader reader2 = new StreamReader(stream2); log.Debug(string.Format("File uploaded, server response is: {0}", reader2.ReadToEnd())); } catch(Exception ex) { log.Error("Error uploading file", ex); if(wresp != null) { wresp.Close(); wresp = null; } } finally { wr = null; } } 

y uso de muestra:

  NameValueCollection nvc = new NameValueCollection(); nvc.Add("id", "TTR"); nvc.Add("btn-submit-photo", "Upload"); HttpUploadFile("http://your.server.com/upload", @"C:\test\test.jpg", "file", "image/jpeg", nvc); 

Podría extenderse para manejar múltiples archivos o simplemente llamarlo varias veces para cada archivo. Sin embargo, se adapta a tus necesidades.

Estaba buscando algo como esto, encontrado en: http://bytes.com/groups/net-c/268661-how-upload-file-via-c-code (modificado para ser correcto):

 public static string UploadFilesToRemoteUrl(string url, string[] files, NameValueCollection formFields = null) { string boundary = "----------------------------" + DateTime.Now.Ticks.ToString("x"); HttpWebRequest request = (HttpWebRequest) WebRequest.Create(url); request.ContentType = "multipart/form-data; boundary=" + boundary; request.Method = "POST"; request.KeepAlive = true; Stream memStream = new System.IO.MemoryStream(); var boundarybytes = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "\r\n"); var endBoundaryBytes = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "--"); string formdataTemplate = "\r\n--" + boundary + "\r\nContent-Disposition: form-data; name=\"{0}\";\r\n\r\n{1}"; if (formFields != null) { foreach (string key in formFields.Keys) { string formitem = string.Format(formdataTemplate, key, formFields[key]); byte[] formitembytes = System.Text.Encoding.UTF8.GetBytes(formitem); memStream.Write(formitembytes, 0, formitembytes.Length); } } string headerTemplate = "Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"\r\n" + "Content-Type: application/octet-stream\r\n\r\n"; for (int i = 0; i < files.Length; i++) { memStream.Write(boundarybytes, 0, boundarybytes.Length); var header = string.Format(headerTemplate, "uplTheFile", files[i]); var headerbytes = System.Text.Encoding.UTF8.GetBytes(header); memStream.Write(headerbytes, 0, headerbytes.Length); using (var fileStream = new FileStream(files[i], FileMode.Open, FileAccess.Read)) { var buffer = new byte[1024]; var bytesRead = 0; while ((bytesRead = fileStream.Read(buffer, 0, buffer.Length)) != 0) { memStream.Write(buffer, 0, bytesRead); } } } memStream.Write(endBoundaryBytes, 0, endBoundaryBytes.Length); request.ContentLength = memStream.Length; using (Stream requestStream = request.GetRequestStream()) { memStream.Position = 0; byte[] tempBuffer = new byte[memStream.Length]; memStream.Read(tempBuffer, 0, tempBuffer.Length); memStream.Close(); requestStream.Write(tempBuffer, 0, tempBuffer.Length); } using (var response = request.GetResponse()) { Stream stream2 = response.GetResponseStream(); StreamReader reader2 = new StreamReader(stream2); return reader2.ReadToEnd(); } } 

ACTUALIZACIÓN: Usando .NET 4.5 (o .NET 4.0 agregando el paquete Microsoft.Net.Http desde NuGet) esto es posible sin código externo, extensiones y manipulación HTTP de “bajo nivel”. Aquí hay un ejemplo:

 // Perform the equivalent of posting a form with a filename and two files, in HTML: // 
// // // //
private async Task UploadAsync(string url, string filename, Stream fileStream, byte [] fileBytes) { // Convert each of the three inputs into HttpContent objects HttpContent stringContent = new StringContent(filename); // examples of converting both Stream and byte [] to HttpContent objects // representing input type file HttpContent fileStreamContent = new StreamContent(fileStream); HttpContent bytesContent = new ByteArrayContent(fileBytes); // Submit the form using HttpClient and // create form data as Multipart (enctype="multipart/form-data") using (var client = new HttpClient()) using (var formData = new MultipartFormDataContent()) { // Add the HttpContent objects to the form data // formData.Add(stringContent, "filename", "filename"); // formData.Add(fileStreamContent, "file1", "file1"); // formData.Add(bytesContent, "file2", "file2"); // Invoke the request to the server // equivalent to pressing the submit button on // a form with attributes (action="{url}" method="post") var response = await client.PostAsync(url, formData); // ensure the request was a success if (!response.IsSuccessStatusCode) { return null; } return await response.Content.ReadAsStreamAsync(); } }

Mis preguntas frecuentes sobre la carga de ASP.NET tienen un artículo sobre esto, con código de ejemplo: Cargue archivos usando una solicitud RFC 1867 POST con HttpWebRequest / WebClient . Este código no carga archivos en la memoria (a diferencia del código anterior), es compatible con varios archivos y admite valores de formulario, establecimiento de credenciales y cookies, etc.

Editar: parece que Axosoft tomó la página. Gracias chicos.

Todavía se puede acceder a través de archive.org.

Basado en el código proporcionado anteriormente, agregué soporte para múltiples archivos y también subí una transmisión directamente sin la necesidad de tener un archivo local.

Para cargar archivos en una url específica, incluidos algunos params de publicación, haga lo siguiente:

 RequestHelper.PostMultipart( "http://sofes.miximages.com/.net/upload.php, new Dictionarystring, object() { { testparam, my value }, { file, new FormFile() { Name = image.jpg", ContentType = "image/jpeg", FilePath = "c:\\temp\\myniceimage.jpg" } }, { "other_file", new FormFile() { Name = "image2.jpg", ContentType = "image/jpeg", Stream = imageDataStream } }, }); 

Para mejorar esto, aún más uno podría determinar el nombre y el tipo de mime del archivo dado.

 public class FormFile { public string Name { get; set; } public string ContentType { get; set; } public string FilePath { get; set; } public Stream Stream { get; set; } } public class RequestHelper { public static string PostMultipart(string url, Dictionary parameters) { string boundary = "---------------------------" + DateTime.Now.Ticks.ToString("x"); byte[] boundaryBytes = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "\r\n"); HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url); request.ContentType = "multipart/form-data; boundary=" + boundary; request.Method = "POST"; request.KeepAlive = true; request.Credentials = System.Net.CredentialCache.DefaultCredentials; if(parameters != null && parameters.Count > 0) { using(Stream requestStream = request.GetRequestStream()) { foreach(KeyValuePair pair in parameters) { requestStream.Write(boundaryBytes, 0, boundaryBytes.Length); if(pair.Value is FormFile) { FormFile file = pair.Value as FormFile; string header = "Content-Disposition: form-data; name=\"" + pair.Key + "\"; filename=\"" + file.Name + "\"\r\nContent-Type: " + file.ContentType + "\r\n\r\n"; byte[] bytes = System.Text.Encoding.UTF8.GetBytes(header); requestStream.Write(bytes, 0, bytes.Length); byte[] buffer = new byte[32768]; int bytesRead; if(file.Stream == null) { // upload from file using(FileStream fileStream = File.OpenRead(file.FilePath)) { while((bytesRead = fileStream.Read(buffer, 0, buffer.Length)) != 0) requestStream.Write(buffer, 0, bytesRead); fileStream.Close(); } } else { // upload from given stream while((bytesRead = file.Stream.Read(buffer, 0, buffer.Length)) != 0) requestStream.Write(buffer, 0, bytesRead); } } else { string data = "Content-Disposition: form-data; name=\"" + pair.Key + "\"\r\n\r\n" + pair.Value; byte[] bytes = System.Text.Encoding.UTF8.GetBytes(data); requestStream.Write(bytes, 0, bytes.Length); } } byte[] trailer = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "--\r\n"); requestStream.Write(trailer, 0, trailer.Length); requestStream.Close(); } } using(WebResponse response = request.GetResponse()) { using(Stream responseStream = response.GetResponseStream()) using(StreamReader reader = new StreamReader(responseStream)) return reader.ReadToEnd(); } } } 

algo así está cerca: (código no probado)

 byte[] data; // data goes here. HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url); request.Credentials = userNetworkCredentials; request.Method = "PUT"; request.ContentType = "application/octet-stream"; request.ContentLength = data.Length; Stream stream = request.GetRequestStream(); stream.Write(data,0,data.Length); stream.Close(); response = (HttpWebResponse)request.GetResponse(); StreamReader reader = new StreamReader(response.GetResponseStream()); temp = reader.ReadToEnd(); reader.Close(); 

Tomado el anterior y modificado, acepta algunos valores de encabezado y varios archivos

  NameValueCollection headers = new NameValueCollection(); headers.Add("Cookie", "name=value;"); headers.Add("Referer", "http://google.com"); NameValueCollection nvc = new NameValueCollection(); nvc.Add("name", "value"); HttpUploadFile(url, new string[] { "c:\\file1.txt", "c:\\file2.jpg" }, new string[] { "file", "image" }, new string[] { "application/octet-stream", "image/jpeg" }, nvc, headers); 

 public static void HttpUploadFile(string url, string[] file, string[] paramName, string[] contentType, NameValueCollection nvc, NameValueCollection headerItems) { //log.Debug(string.Format("Uploading {0} to {1}", file, url)); string boundary = "---------------------------" + DateTime.Now.Ticks.ToString("x"); byte[] boundarybytes = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "\r\n"); HttpWebRequest wr = (HttpWebRequest)WebRequest.Create(url); foreach (string key in headerItems.Keys) { if (key == "Referer") { wr.Referer = headerItems[key]; } else { wr.Headers.Add(key, headerItems[key]); } } wr.ContentType = "multipart/form-data; boundary=" + boundary; wr.Method = "POST"; wr.KeepAlive = true; wr.Credentials = System.Net.CredentialCache.DefaultCredentials; Stream rs = wr.GetRequestStream(); string formdataTemplate = "Content-Disposition: form-data; name=\"{0}\"\r\n\r\n{1}"; foreach (string key in nvc.Keys) { rs.Write(boundarybytes, 0, boundarybytes.Length); string formitem = string.Format(formdataTemplate, key, nvc[key]); byte[] formitembytes = System.Text.Encoding.UTF8.GetBytes(formitem); rs.Write(formitembytes, 0, formitembytes.Length); } rs.Write(boundarybytes, 0, boundarybytes.Length); string headerTemplate = "Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"\r\nContent-Type: {2}\r\n\r\n"; string header = ""; for(int i =0; i 

Creo que estás buscando algo más parecido a WebClient .

Específicamente, UploadFile () .

Ejemplo de VB (convertido desde el ejemplo de C # en otra publicación):

 Private Sub HttpUploadFile( _ ByVal uri As String, _ ByVal filePath As String, _ ByVal fileParameterName As String, _ ByVal contentType As String, _ ByVal otherParameters As Specialized.NameValueCollection) Dim boundary As String = "---------------------------" & DateTime.Now.Ticks.ToString("x") Dim newLine As String = System.Environment.NewLine Dim boundaryBytes As Byte() = Text.Encoding.ASCII.GetBytes(newLine & "--" & boundary & newLine) Dim request As Net.HttpWebRequest = Net.WebRequest.Create(uri) request.ContentType = "multipart/form-data; boundary=" & boundary request.Method = "POST" request.KeepAlive = True request.Credentials = Net.CredentialCache.DefaultCredentials Using requestStream As IO.Stream = request.GetRequestStream() Dim formDataTemplate As String = "Content-Disposition: form-data; name=""{0}""{1}{1}{2}" For Each key As String In otherParameters.Keys requestStream.Write(boundaryBytes, 0, boundaryBytes.Length) Dim formItem As String = String.Format(formDataTemplate, key, newLine, otherParameters(key)) Dim formItemBytes As Byte() = Text.Encoding.UTF8.GetBytes(formItem) requestStream.Write(formItemBytes, 0, formItemBytes.Length) Next key requestStream.Write(boundaryBytes, 0, boundaryBytes.Length) Dim headerTemplate As String = "Content-Disposition: form-data; name=""{0}""; filename=""{1}""{2}Content-Type: {3}{2}{2}" Dim header As String = String.Format(headerTemplate, fileParameterName, filePath, newLine, contentType) Dim headerBytes As Byte() = Text.Encoding.UTF8.GetBytes(header) requestStream.Write(headerBytes, 0, headerBytes.Length) Using fileStream As New IO.FileStream(filePath, IO.FileMode.Open, IO.FileAccess.Read) Dim buffer(4096) As Byte Dim bytesRead As Int32 = fileStream.Read(buffer, 0, buffer.Length) Do While (bytesRead > 0) requestStream.Write(buffer, 0, bytesRead) bytesRead = fileStream.Read(buffer, 0, buffer.Length) Loop End Using Dim trailer As Byte() = Text.Encoding.ASCII.GetBytes(newLine & "--" + boundary + "--" & newLine) requestStream.Write(trailer, 0, trailer.Length) End Using Dim response As Net.WebResponse = Nothing Try response = request.GetResponse() Using responseStream As IO.Stream = response.GetResponseStream() Using responseReader As New IO.StreamReader(responseStream) Dim responseText = responseReader.ReadToEnd() Diagnostics.Debug.Write(responseText) End Using End Using Catch exception As Net.WebException response = exception.Response If (response IsNot Nothing) Then Using reader As New IO.StreamReader(response.GetResponseStream()) Dim responseText = reader.ReadToEnd() Diagnostics.Debug.Write(responseText) End Using response.Close() End If Finally request = Nothing End Try End Sub 

Tuve que lidiar con esto recientemente. Otra forma de abordarlo es utilizar el hecho de que WebClient es heredable y cambiar la WebRequest subyacente desde allí:

http://msdn.microsoft.com/en-us/library/system.net.webclient.getwebrequest(VS.80).aspx

Prefiero C #, pero si estás atrapado con VB, los resultados se verán más o menos así:

 Public Class BigWebClient Inherits WebClient Protected Overrides Function GetWebRequest(ByVal address As System.Uri) As System.Net.WebRequest Dim x As WebRequest = MyBase.GetWebRequest(address) x.Timeout = 60 * 60 * 1000 Return x End Function End Class 'Use BigWebClient here instead of WebClient 

Hay otro ejemplo de trabajo con algunos de mis comentarios:

  List mimeParts = new List(); try { foreach (string key in form.AllKeys) { StringMimePart part = new StringMimePart(); part.Headers["Content-Disposition"] = "form-data; name=\"" + key + "\""; part.StringData = form[key]; mimeParts.Add(part); } int nameIndex = 0; foreach (UploadFile file in files) { StreamMimePart part = new StreamMimePart(); if (string.IsNullOrEmpty(file.FieldName)) file.FieldName = "file" + nameIndex++; part.Headers["Content-Disposition"] = "form-data; name=\"" + file.FieldName + "\"; filename=\"" + file.FileName + "\""; part.Headers["Content-Type"] = file.ContentType; part.SetStream(file.Data); mimeParts.Add(part); } string boundary = "----------" + DateTime.Now.Ticks.ToString("x"); req.ContentType = "multipart/form-data; boundary=" + boundary; req.Method = "POST"; long contentLength = 0; byte[] _footer = Encoding.UTF8.GetBytes("--" + boundary + "--\r\n"); foreach (MimePart part in mimeParts) { contentLength += part.GenerateHeaderFooterData(boundary); } req.ContentLength = contentLength + _footer.Length; byte[] buffer = new byte[8192]; byte[] afterFile = Encoding.UTF8.GetBytes("\r\n"); int read; using (Stream s = req.GetRequestStream()) { foreach (MimePart part in mimeParts) { s.Write(part.Header, 0, part.Header.Length); while ((read = part.Data.Read(buffer, 0, buffer.Length)) > 0) s.Write(buffer, 0, read); part.Data.Dispose(); s.Write(afterFile, 0, afterFile.Length); } s.Write(_footer, 0, _footer.Length); } return (HttpWebResponse)req.GetResponse(); } catch { foreach (MimePart part in mimeParts) if (part.Data != null) part.Data.Dispose(); throw; } 

Y hay un ejemplo de uso:

  UploadFile[] files = new UploadFile[] { new UploadFile(@"C:\2.jpg","new_file","image/jpeg") //new_file is id of upload field }; NameValueCollection form = new NameValueCollection(); form["id_hidden_input"] = "value_hidden_inpu"; //there is additional param (hidden fields on page) HttpWebRequest req = (HttpWebRequest)WebRequest.Create(full URL of action); // set credentials/cookies etc. req.CookieContainer = hrm.CookieContainer; //hrm is my class. i copied all cookies from last request to current (for auth) HttpWebResponse resp = HttpUploadHelper.Upload(req, files, form); using (Stream s = resp.GetResponseStream()) using (StreamReader sr = new StreamReader(s)) { string response = sr.ReadToEnd(); } //profit! 

Estaba buscando hacer la carga de archivos y agregar algunos parámetros a una solicitud multipart / form-data en VB.NET y no a través de una publicación regular de formularios. Gracias a la respuesta de @JoshCodes obtuve la dirección que estaba buscando. Estoy publicando mi solución para ayudar a otros a encontrar la forma de realizar una publicación con ambos archivos y parámetros, el equivalente html de lo que bash lograr es: html

 

Debido al hecho de que tengo que proporcionar la clave y la firma (que es una sum de comprobación calculada de los parámetros de solicitud y la cadena concatenada de la clave api), tenía que hacerlo desde el lado del servidor. La otra razón por la que tuve que hacerlo desde el lado del servidor es el hecho de que la publicación del archivo se puede realizar en cualquier momento apuntando a un archivo que ya está en el servidor (proporcionando la ruta), por lo que no habría ningún archivo seleccionado manualmente durante el formulario publicar así el archivo de datos no contendría la secuencia de archivos. De lo contrario, podría haber calculado la sum de verificación a través de una callback ajax y enviado el archivo a través de la publicación html usando JQuery. Estoy usando .net versión 4.0 y no puedo actualizar a 4.5 en la solución real. Así que tuve que instalar Microsoft.Net.Http usando nuget cmd

 PM> install-package Microsoft.Net.Http Private Function UploadFile(req As ApiRequest, filePath As String, fileName As String) As String Dim result = String.empty Try ''//Get file stream Dim paramFileStream As Stream = File.OpenRead(filePath) Dim fileStreamContent As HttpContent = New StreamContent(paramFileStream) Using client = New HttpClient() Using formData = New MultipartFormDataContent() ''// This adds parameter name ("action") ''// parameter value (req.Action) to form data formData.Add(New StringContent(req.Action), "action") formData.Add(New StringContent(req.ApiKey), "apiKey") For Each param In req.Parameters formData.Add(New StringContent(param.Value), param.Key) Next formData.Add(New StringContent(req.getRequestSignature.Qualifier), "signature") ''//This adds the file stream and file info to form data formData.Add(fileStreamContent, "file", fileName) ''//We are now sending the request Dim response = client.PostAsync(GetAPIEndpoint(), formData).Result ''//We are here reading the response Dim readR = New StreamReader(response.Content.ReadAsStreamAsync().Result, Encoding.UTF8) Dim respContent = readR.ReadToEnd() If Not response.IsSuccessStatusCode Then result = "Request Failed : Code = " & response.StatusCode & "Reason = " & response.ReasonPhrase & "Message = " & respContent End If result.Value = respContent End Using End Using Catch ex As Exception result = "An error occurred : " & ex.Message End Try Return result End Function 

No estoy seguro de si esto fue publicado antes, pero lo hice trabajando con WebClient. Leí la documentación del WebClient. Un punto clave que hacen es

Si la propiedad BaseAddress no es una cadena vacía (“”) y la dirección no contiene un URI absoluto, la dirección debe ser un URI relativo que se combina con BaseAddress para formar el URI absoluto de los datos solicitados. Si la propiedad QueryString no es una cadena vacía, se anexa a la dirección.

Así que todo lo que hice fue wc.QueryString.Add (“source”, generatedImage) para agregar los diferentes parámetros de consulta y de alguna manera coincide con el nombre de la propiedad con la imagen que cargué. Espero eso ayude

  public void postImageToFacebook(string generatedImage, string fbGraphUrl) { WebClient wc = new WebClient(); byte[] bytes = System.IO.File.ReadAllBytes(generatedImage); wc.QueryString.Add("source", generatedImage); wc.QueryString.Add("message", "helloworld"); wc.UploadFile(fbGraphUrl, generatedImage); wc.Dispose(); } 

Se modificó el código @CristianRomanescu para que funcione con el flujo de memoria, se acepte el archivo como una matriz de bytes, se permita nvl nvc, se devuelva la respuesta de solicitud y se trabaje con Authorization-header. Probado el código con Web Api 2.

 private string HttpUploadFile(string url, byte[] file, string fileName, string paramName, string contentType, NameValueCollection nvc, string authorizationHeader) { string boundary = "---------------------------" + DateTime.Now.Ticks.ToString("x"); byte[] boundarybytes = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "\r\n"); HttpWebRequest wr = (HttpWebRequest)WebRequest.Create(url); wr.ContentType = "multipart/form-data; boundary=" + boundary; wr.Method = "POST"; wr.Headers.Add("Authorization", authorizationHeader); wr.KeepAlive = true; Stream rs = wr.GetRequestStream(); string formdataTemplate = "Content-Disposition: form-data; name=\"{0}\"\r\n\r\n{1}"; if (nvc != null) { foreach (string key in nvc.Keys) { rs.Write(boundarybytes, 0, boundarybytes.Length); string formitem = string.Format(formdataTemplate, key, nvc[key]); byte[] formitembytes = System.Text.Encoding.UTF8.GetBytes(formitem); rs.Write(formitembytes, 0, formitembytes.Length); } } rs.Write(boundarybytes, 0, boundarybytes.Length); string headerTemplate = "Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"\r\nContent-Type: {2}\r\n\r\n"; string header = string.Format(headerTemplate, paramName, fileName, contentType); byte[] headerbytes = System.Text.Encoding.UTF8.GetBytes(header); rs.Write(headerbytes, 0, headerbytes.Length); rs.Write(file, 0, file.Length); byte[] trailer = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "--\r\n"); rs.Write(trailer, 0, trailer.Length); rs.Close(); WebResponse wresp = null; try { wresp = wr.GetResponse(); Stream stream2 = wresp.GetResponseStream(); StreamReader reader2 = new StreamReader(stream2); var response = reader2.ReadToEnd(); return response; } catch (Exception ex) { if (wresp != null) { wresp.Close(); wresp = null; } return null; } finally { wr = null; } } 

Código de prueba:

 [HttpPost] [Route("postformdata")] public IHttpActionResult PostFormData() { // Check if the request contains multipart/form-data. if (!Request.Content.IsMimeMultipartContent()) { throw new HttpResponseException(HttpStatusCode.UnsupportedMediaType); } var provider = new MultipartMemoryStreamProvider(); try { // Read the form data. var result = Request.Content.ReadAsMultipartAsync(provider).Result; string response = ""; // This illustrates how to get the file names. foreach (var file in provider.Contents) { var fileName = file.Headers.ContentDisposition.FileName.Trim('\"'); var buffer = file.ReadAsByteArrayAsync().Result; response = HttpUploadFile("https://localhost/api/v1/createfromfile", buffer, fileName, "file", "application/pdf", null, "AuthorizationKey"); } return Ok(response); } catch (System.Exception e) { return InternalServerError(); } } 

Escribí una clase usando WebClient hace mucho tiempo para hacer una carga de formulario multiparte.

http://ferozedaud.blogspot.com/2010/03/multipart-form-upload-helper.html

 /// /// MimePart /// Abstract class for all MimeParts /// abstract class MimePart { public string Name { get; set; } public abstract string ContentDisposition { get; } public abstract string ContentType { get; } public abstract void CopyTo(Stream stream); public String Boundary { get; set; } } class NameValuePart : MimePart { private NameValueCollection nameValues; public NameValuePart(NameValueCollection nameValues) { this.nameValues = nameValues; } public override void CopyTo(Stream stream) { string boundary = this.Boundary; StringBuilder sb = new StringBuilder(); foreach (object element in this.nameValues.Keys) { sb.AppendFormat("--{0}", boundary); sb.Append("\r\n"); sb.AppendFormat("Content-Disposition: form-data; name=\"{0}\";", element); sb.Append("\r\n"); sb.Append("\r\n"); sb.Append(this.nameValues[element.ToString()]); sb.Append("\r\n"); } sb.AppendFormat("--{0}", boundary); sb.Append("\r\n"); //Trace.WriteLine(sb.ToString()); byte [] data = Encoding.ASCII.GetBytes(sb.ToString()); stream.Write(data, 0, data.Length); } public override string ContentDisposition { get { return "form-data"; } } public override string ContentType { get { return String.Empty; } } } class FilePart : MimePart { private Stream input; private String contentType; public FilePart(Stream input, String name, String contentType) { this.input = input; this.contentType = contentType; this.Name = name; } public override void CopyTo(Stream stream) { StringBuilder sb = new StringBuilder(); sb.AppendFormat("Content-Disposition: {0}", this.ContentDisposition); if (this.Name != null) sb.Append("; ").AppendFormat("name=\"{0}\"", this.Name); if (this.FileName != null) sb.Append("; ").AppendFormat("filename=\"{0}\"", this.FileName); sb.Append("\r\n"); sb.AppendFormat(this.ContentType); sb.Append("\r\n"); sb.Append("\r\n"); // serialize the header data. byte[] buffer = Encoding.ASCII.GetBytes(sb.ToString()); stream.Write(buffer, 0, buffer.Length); // send the stream. byte[] readBuffer = new byte[1024]; int read = input.Read(readBuffer, 0, readBuffer.Length); while (read > 0) { stream.Write(readBuffer, 0, read); read = input.Read(readBuffer, 0, readBuffer.Length); } // write the terminating boundary sb.Length = 0; sb.Append("\r\n"); sb.AppendFormat("--{0}", this.Boundary); sb.Append("\r\n"); buffer = Encoding.ASCII.GetBytes(sb.ToString()); stream.Write(buffer, 0, buffer.Length); } public override string ContentDisposition { get { return "file"; } } public override string ContentType { get { return String.Format("content-type: {0}", this.contentType); } } public String FileName { get; set; } } /// /// Helper class that encapsulates all file uploads /// in a mime part. /// class FilesCollection : MimePart { private List files; public FilesCollection() { this.files = new List(); this.Boundary = MultipartHelper.GetBoundary(); } public int Count { get { return this.files.Count; } } public override string ContentDisposition { get { return String.Format("form-data; name=\"{0}\"", this.Name); } } public override string ContentType { get { return String.Format("multipart/mixed; boundary={0}", this.Boundary); } } public override void CopyTo(Stream stream) { // serialize the headers StringBuilder sb = new StringBuilder(128); sb.Append("Content-Disposition: ").Append(this.ContentDisposition).Append("\r\n"); sb.Append("Content-Type: ").Append(this.ContentType).Append("\r\n"); sb.Append("\r\n"); sb.AppendFormat("--{0}", this.Boundary).Append("\r\n"); byte[] headerBytes = Encoding.ASCII.GetBytes(sb.ToString()); stream.Write(headerBytes, 0, headerBytes.Length); foreach (FilePart part in files) { part.Boundary = this.Boundary; part.CopyTo(stream); } } public void Add(FilePart part) { this.files.Add(part); } } /// /// Helper class to aid in uploading multipart /// entities to HTTP web endpoints. /// class MultipartHelper { private static Random random = new Random(Environment.TickCount); private List formData = new List(); private FilesCollection files = null; private MemoryStream bufferStream = new MemoryStream(); private string boundary; public String Boundary { get { return boundary; } } public static String GetBoundary() { return Environment.TickCount.ToString("X"); } public MultipartHelper() { this.boundary = MultipartHelper.GetBoundary(); } public void Add(NameValuePart part) { this.formData.Add(part); part.Boundary = boundary; } public void Add(FilePart part) { if (files == null) { files = new FilesCollection(); } this.files.Add(part); } public void Upload(WebClient client, string address, string method) { // set header client.Headers.Add(HttpRequestHeader.ContentType, "multipart/form-data; boundary=" + this.boundary); Trace.WriteLine("Content-Type: multipart/form-data; boundary=" + this.boundary + "\r\n"); // first, serialize the form data foreach (NameValuePart part in this.formData) { part.CopyTo(bufferStream); } // serialize the files. this.files.CopyTo(bufferStream); if (this.files.Count > 0) { // add the terminating boundary. StringBuilder sb = new StringBuilder(); sb.AppendFormat("--{0}", this.Boundary).Append("\r\n"); byte [] buffer = Encoding.ASCII.GetBytes(sb.ToString()); bufferStream.Write(buffer, 0, buffer.Length); } bufferStream.Seek(0, SeekOrigin.Begin); Trace.WriteLine(Encoding.ASCII.GetString(bufferStream.ToArray())); byte [] response = client.UploadData(address, method, bufferStream.ToArray()); Trace.WriteLine("----- RESPONSE ------"); Trace.WriteLine(Encoding.ASCII.GetString(response)); } /// /// Helper class that encapsulates all file uploads /// in a mime part. /// class FilesCollection : MimePart { private List files; public FilesCollection() { this.files = new List(); this.Boundary = MultipartHelper.GetBoundary(); } public int Count { get { return this.files.Count; } } public override string ContentDisposition { get { return String.Format("form-data; name=\"{0}\"", this.Name); } } public override string ContentType { get { return String.Format("multipart/mixed; boundary={0}", this.Boundary); } } public override void CopyTo(Stream stream) { // serialize the headers StringBuilder sb = new StringBuilder(128); sb.Append("Content-Disposition: ").Append(this.ContentDisposition).Append("\r\n"); sb.Append("Content-Type: ").Append(this.ContentType).Append("\r\n"); sb.Append("\r\n"); sb.AppendFormat("--{0}", this.Boundary).Append("\r\n"); byte[] headerBytes = Encoding.ASCII.GetBytes(sb.ToString()); stream.Write(headerBytes, 0, headerBytes.Length); foreach (FilePart part in files) { part.Boundary = this.Boundary; part.CopyTo(stream); } } public void Add(FilePart part) { this.files.Add(part); } } } class Program { static void Main(string[] args) { Trace.Listeners.Add(new ConsoleTraceListener()); try { using (StreamWriter sw = new StreamWriter("testfile.txt", false)) { sw.Write("Hello there!"); } using (Stream iniStream = File.OpenRead(@"c:\platform.ini")) using (Stream fileStream = File.OpenRead("testfile.txt")) using (WebClient client = new WebClient()) { MultipartHelper helper = new MultipartHelper(); NameValueCollection props = new NameValueCollection(); props.Add("fname", "john"); props.Add("id", "acme"); helper.Add(new NameValuePart(props)); FilePart filepart = new FilePart(fileStream, "pics1", "text/plain"); filepart.FileName = "1.jpg"; helper.Add(filepart); FilePart ini = new FilePart(iniStream, "pics2", "text/plain"); ini.FileName = "inifile.ini"; helper.Add(ini); helper.Upload(client, "http://localhost/form.aspx", "POST"); } } catch (Exception e) { Trace.WriteLine(e); } } } 

This will work with all versions of the .NET framework.

I can never get the examples to work properly, I always receive a 500 error when sending it to the server.

However I came across a very elegant method of doing it in this url

It is easily extendible and obviously works with binary files as well as XML.

You call it using something similar to this

 class Program { public static string gsaFeedURL = "http://yourGSA.domain.com:19900/xmlfeed"; static void Main() { try { postWebData(); } catch (Exception ex) { } } // new one I made from C# web service public static void postWebData() { StringDictionary dictionary = new StringDictionary(); UploadSpec uploadSpecs = new UploadSpec(); UTF8Encoding encoding = new UTF8Encoding(); byte[] bytes; Uri gsaURI = new Uri(gsaFeedURL); // Create new URI to GSA feeder gate string sourceURL = @"C:\FeedFile.xml"; // Location of the XML feed file // Two parameters to send string feedtype = "full"; string datasource = "test"; try { // Add the parameter values to the dictionary dictionary.Add("feedtype", feedtype); dictionary.Add("datasource", datasource); // Load the feed file created and get its bytes XmlDocument xml = new XmlDocument(); xml.Load(sourceURL); bytes = Encoding.UTF8.GetBytes(xml.OuterXml); // Add data to upload specs uploadSpecs.Contents = bytes; uploadSpecs.FileName = sourceURL; uploadSpecs.FieldName = "data"; // Post the data if ((int)HttpUpload.Upload(gsaURI, dictionary, uploadSpecs).StatusCode == 200) { Console.WriteLine("Successful."); } else { // GSA POST not successful Console.WriteLine("Failure."); } } catch (Exception ex) { Console.WriteLine(ex.Message); } } } 

For me, the following works (mostly inspirated from all of the following answers), I started from Elad’s answer and modify/simplify things to match my need (remove not file form inputs, only one file, …).

Hope it can helps somebody 🙂

(PS: I know that exception handling is not implemented and it assumes that it was written inside a class, so I may need some integration effort…)

 private void uploadFile() { Random rand = new Random(); string boundary = "----boundary" + rand.Next().ToString(); Stream data_stream; byte[] header = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "\r\nContent-Disposition: form-data; name=\"file_path\"; filename=\"" + System.IO.Path.GetFileName(this.file) + "\"\r\nContent-Type: application/octet-stream\r\n\r\n"); byte[] trailer = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "--\r\n"); // Do the request HttpWebRequest request = (HttpWebRequest)WebRequest.Create(MBF_URL); request.UserAgent = "My Toolbox"; request.Method = "POST"; request.KeepAlive = true; request.ContentType = "multipart/form-data; boundary=" + boundary; data_stream = request.GetRequestStream(); data_stream.Write(header, 0, header.Length); byte[] file_bytes = System.IO.File.ReadAllBytes(this.file); data_stream.Write(file_bytes, 0, file_bytes.Length); data_stream.Write(trailer, 0, trailer.Length); data_stream.Close(); // Read the response WebResponse response = request.GetResponse(); data_stream = response.GetResponseStream(); StreamReader reader = new StreamReader(data_stream); this.url = reader.ReadToEnd(); if (this.url == "") { this.url = "No response :("; } reader.Close(); data_stream.Close(); response.Close(); } 

Check out the MyToolkit library:

 var request = new HttpPostRequest("http://www.server.com"); request.Data.Add("name", "value"); // POST data request.Files.Add(new HttpPostFile("name", "file.jpg", "path/to/file.jpg")); await Http.PostAsync(request, OnRequestFinished); 

http://mytoolkit.codeplex.com/wikipage?title=Http

Client use convert File to ToBase64String , after use Xml to promulgate to Server call, this server use File.WriteAllBytes(path,Convert.FromBase64String(dataFile_Client_sent)) .

Good lucky!

I realize this is probably really late, but I was searching for the same solution. I found the following response from a Microsoft rep

 private void UploadFilesToRemoteUrl(string url, string[] files, string logpath, NameValueCollection nvc) { long length = 0; string boundary = "----------------------------" + DateTime.Now.Ticks.ToString("x"); HttpWebRequest httpWebRequest2 = (HttpWebRequest)WebRequest.Create(url); httpWebRequest2.ContentType = "multipart/form-data; boundary=" + boundary; httpWebRequest2.Method = "POST"; httpWebRequest2.KeepAlive = true; httpWebRequest2.Credentials = System.Net.CredentialCache.DefaultCredentials; Stream memStream = new System.IO.MemoryStream(); byte[] boundarybytes = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "\r\n"); string formdataTemplate = "\r\n--" + boundary + "\r\nContent-Disposition: form-data; name=\"{0}\";\r\n\r\n{1}"; foreach(string key in nvc.Keys) { string formitem = string.Format(formdataTemplate, key, nvc[key]); byte[] formitembytes = System.Text.Encoding.UTF8.GetBytes(formitem); memStream.Write(formitembytes, 0, formitembytes.Length); } memStream.Write(boundarybytes,0,boundarybytes.Length); string headerTemplate = "Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"\r\n Content-Type: application/octet-stream\r\n\r\n"; for(int i=0;i