publicclassPostData{ privateList m_Params;publicList Params{ get { return m_Params;}set{ m_Params = value;}}publicPostData(){ m_Params =newList ();// Add sample param m_Params.Add(newPostDataParam("email","MyEmail",PostDataParamType.Field));}/// /// Returns the parameters array formatted for multi-part/form data/// /// To send the data you then need to:
HttpWebRequest oRequest =null;oRequest =(HttpWebRequest)HttpWebRequest.Create(oURL.URL);oRequest.ContentType="multipart/form-data"; oRequest.Method="POST";PostData pData =newPostData();byte[] buffer = encoding.GetBytes(pData.GetPostData());// Set content length of our dataoRequest.ContentLength= buffer.Length;// Dump our buffered postdata to the stream, booyahoStream = oRequest.GetRequestStream();oStream.Write(buffer,0, buffer.Length);oStream.Close();// get the responseoResponse =(HttpWebResponse)oRequest.GetResponse();
Here is the FormUpload class:
// Implements multipart/form-data POST in C# http://www.ietf.org/rfc/rfc2388.txt// http://www.briangrinstead.com/blog/multipart-form-post-in-cpublicstaticclassFormUpload{ privatestaticreadonlyEncoding encoding =Encoding.UTF8;publicstaticHttpWebResponseMultipartFormDataPost(string postUrl,string userAgent,Dictionary postParameters){ string formDataBoundary =String.Format("----------{0:N}",Guid.NewGuid());string contentType ="multipart/form-data; boundary="+ formDataBoundary;byte[] formData =GetMultipartFormData(postParameters, formDataBoundary);returnPostForm(postUrl, userAgent, contentType, formData);}privatestaticHttpWebResponsePostForm(string postUrl,string userAgent,string contentType,byte[] formData){ HttpWebRequest request =WebRequest.Create(postUrl)asHttpWebRequest;if(request ==null){ thrownewNullReferenceException("request is not a http request");}// Set up the request properties. request.Method="POST"; request.ContentType= contentType; request.UserAgent= userAgent; request.CookieContainer=newCookieContainer(); request.ContentLength= formData.Length;// You could add authentication here as well if needed:// request.PreAuthenticate = true;// request.AuthenticationLevel = System.Net.Security.AuthenticationLevel.MutualAuthRequested;// request.Headers.Add("Authorization", "Basic " + Convert.ToBase64String(System.Text.Encoding.Default.GetBytes("username" + ":" + "password")));// Send the form data to the request. using (Stream requestStream = request.GetRequestStream()){ requestStream.Write(formData,0, formData.Length); requestStream.Close();}return request.GetResponse()asHttpWebResponse;}privatestaticbyte[]GetMultipartFormData(Dictionary postParameters,string boundary){ Stream formDataStream =newSystem.IO.MemoryStream(); bool needsCLRF =false;foreach(var param in postParameters){ // Thanks to feedback from commenters, add a CRLF to allow multiple parameters to be added.// Skip it on the first parameter, add it to subsequent parameters.if(needsCLRF) formDataStream.Write(encoding.GetBytes("\r\n"),0, encoding.GetByteCount("\r\n")); needsCLRF =true;if(param.ValueisFileParameter){ FileParameter fileToUpload =(FileParameter)param.Value;// Add just the first part of this param, since we will write the file data directly to the Streamstring header =string.Format("--{0}\r\nContent-Disposition: form-data; name=\"{1}\"; filename=\"{2}\";\r\nContent-Type: {3}\r\n\r\n", boundary, param.Key, fileToUpload.FileName?? param.Key, fileToUpload.ContentType??"application/octet-stream"); formDataStream.Write(encoding.GetBytes(header),0, encoding.GetByteCount(header));// Write the file data directly to the Stream, rather than serializing it to a string. formDataStream.Write(fileToUpload.File,0, fileToUpload.File.Length);}else{ string postData =string.Format("--{0}\r\nContent-Disposition: form-data; name=\"{1}\"\r\n\r\n{2}", boundary, param.Key, param.Value); formDataStream.Write(encoding.GetBytes(postData),0, encoding.GetByteCount(postData));}}// Add the end of the request. Start with a newlinestring footer ="\r\n--"+ boundary +"--\r\n"; formDataStream.Write(encoding.GetBytes(footer),0, encoding.GetByteCount(footer));// Dump the Stream into a byte[] formDataStream.Position=0;byte[] formData =newbyte[formDataStream.Length]; formDataStream.Read(formData,0, formData.Length); formDataStream.Close();return formData;}publicclassFileParameter{ publicbyte[]File{ get;set;}publicstringFileName{ get;set;}publicstringContentType{ get;set;}publicFileParameter(byte[] file):this(file,null){ }publicFileParameter(byte[] file,string filename):this(file, filename,null){ }publicFileParameter(byte[] file,string filename,string contenttype){ File= file;FileName= filename;ContentType= contenttype;}}} Here is the calling code, which uploads a file and a few normal post parameters:
// Read file dataFileStream fs =newFileStream("c:\\people.doc",FileMode.Open,FileAccess.Read);byte[] data =newbyte[fs.Length];fs.Read(data,0, data.Length);fs.Close();// Generate post objectsDictionary postParameters =newDictionary ();postParameters.Add("filename","People.doc");postParameters.Add("fileformat","doc");postParameters.Add("file",newFormUpload.FileParameter(data,"People.doc","application/msword"));// Create request and receive responsestring postURL ="http://localhost";string userAgent ="Someone";HttpWebResponse webResponse =FormUpload.MultipartFormDataPost(postURL, userAgent, postParameters);// Process responseStreamReader responseReader =newStreamReader(webResponse.GetResponseStream());string fullResponse = responseReader.ReadToEnd();webResponse.Close();Response.Write(fullResponse); Building on dnolans example, this is the version I could actually get to work (there were some errors with the boundary, encoding wasn't set) :-)
To send the data:
HttpWebRequest oRequest =null;oRequest =(HttpWebRequest)HttpWebRequest.Create("http://you.url.here");oRequest.ContentType="multipart/form-data; boundary="+PostData.boundary;oRequest.Method="POST";PostData pData =newPostData();Encoding encoding =Encoding.UTF8;Stream oStream =null;/* ... set the parameters, read files, etc. IE: pData.Params.Add(new PostDataParam("email", "example@example.com", PostDataParamType.Field)); pData.Params.Add(new PostDataParam("fileupload", "filename.txt", "filecontents" PostDataParamType.File));*/byte[] buffer = encoding.GetBytes(pData.GetPostData());oRequest.ContentLength= buffer.Length;oStream = oRequest.GetRequestStream();oStream.Write(buffer,0, buffer.Length);oStream.Close();HttpWebResponse oResponse =(HttpWebResponse)oRequest.GetResponse(); The PostData class should look like:
publicclassPostData{ // Change this if you need to, not necessarypublicstaticstring boundary ="AaB03x";privateList m_Params;publicList Params{ get { return m_Params;}set{ m_Params = value;}}publicPostData(){ m_Params =newList ();}/// /// Returns the parameters array formatted for multi-part/form data/// /// namespace WindowsFormsApplication1{ publicstaticclassFormUpload{ privatestaticstringNewDataBoundary(){ Random rnd =newRandom();string formDataBoundary ="";while(formDataBoundary.Length<15){ formDataBoundary = formDataBoundary + rnd.Next();} formDataBoundary = formDataBoundary.Substring(0,15); formDataBoundary ="-----------------------------"+ formDataBoundary;return formDataBoundary;}publicstaticHttpWebResponseMultipartFormDataPost(string postUrl,IEnumerable cookies,Dictionary postParameters){ string boundary =NewDataBoundary();HttpWebRequest request =(HttpWebRequest)WebRequest.Create(postUrl);// Set up the request properties request.Method="POST"; request.ContentType="multipart/form-data; boundary="+ boundary; request.UserAgent="PhasDocAgent 1.0"; request.CookieContainer=newCookieContainer();foreach(var cookie in cookies){ request.CookieContainer.Add(cookie);}#region WRITING STREAM using (Stream formDataStream = request.GetRequestStream()){ foreach(var param in postParameters){ if(param.Value.StartsWith("file://")){ string filepath = param.Value.Substring(7);// Add just the first part of this param, since we will write the file data directly to the Streamstring header =string.Format("--{0}\r\nContent-Disposition: form-data; name=\"{1}\"; filename=\"{2}\";\r\nContent-Type: {3}\r\n\r\n", boundary, param.Key,Path.GetFileName(filepath)?? param.Key,MimeTypes.GetMime(filepath)); formDataStream.Write(Encoding.UTF8.GetBytes(header),0, header.Length);// Write the file data directly to the Stream, rather than serializing it to a string.byte[] buffer =newbyte[2048];FileStream fs =newFileStream(filepath,FileMode.Open);for(int i =0; i < fs.Length;){ int k = fs.Read(buffer,0, buffer.Length);if(k >0){ formDataStream.Write(buffer,0, k);} i = i + k;} fs.Close();}else{ string postData =string.Format("--{0}\r\nContent-Disposition: form-data; name=\"{1}\"\r\n\r\n{2}\r\n", boundary, param.Key, param.Value); formDataStream.Write(Encoding.UTF8.GetBytes(postData),0, postData.Length);}}// Add the end of the requestbyte[] footer =Encoding.UTF8.GetBytes("\r\n--"+ boundary +"--\r\n"); formDataStream.Write(footer,0, footer.Length); request.ContentLength= formDataStream.Length; formDataStream.Close();}#endregionreturn request.GetResponse()asHttpWebResponse;}}}