Question

I am trying to fill a form in a php application from a C# client (Outlook addin). I used Fiddler to see the original request from within the php application and the form is transmitted as a multipart/form. Unfortunately .Net does not come with native support for this type of forms (WebClient has only a method for uploading a file). Does anybody know a library or has some code to achieve this? I want to post different values and additionally (but only sometimes) a file.

Thanks for your help, Sebastian

Answer 1

This is cut and pasted from some sample code I wrote, hopefully it should give the basics. It only supports File data and form-data at the moment.

public class PostData {      private List<PostDataParam> m_Params;      public List<PostDataParam> Params     {         get { return m_Params; }         set { m_Params = value; }     }      public PostData()     {         m_Params = new List<PostDataParam>();          // Add sample param         m_Params.Add(new PostDataParam('email', 'MyEmail', PostDataParamType.Field));     }       /// <summary>     /// Returns the parameters array formatted for multi-part/form data     /// </summary>     /// <returns></returns>     public string GetPostData()     {         // Get boundary, default is --AaB03x         string boundary = ConfigurationManager.AppSettings['ContentBoundary'].ToString();          StringBuilder sb = new StringBuilder();         foreach (PostDataParam p in m_Params)         {             sb.AppendLine(boundary);              if (p.Type == PostDataParamType.File)             {                 sb.AppendLine(string.Format('Content-Disposition: file; name=\'{0}\'; filename=\'{1}\'', p.Name, p.FileName));                 sb.AppendLine('Content-Type: text/plain');                 sb.AppendLine();                 sb.AppendLine(p.Value);                              }             else             {                 sb.AppendLine(string.Format('Content-Disposition: form-data; name=\'{0}\'', p.Name));                 sb.AppendLine();                 sb.AppendLine(p.Value);             }         }          sb.AppendLine(boundary);          return sb.ToString();                } }  public enum PostDataParamType {     Field,     File }  public class PostDataParam {       public PostDataParam(string name, string value, PostDataParamType type)     {         Name = name;         Value = value;         Type = type;     }      public string Name;     public string FileName;     public string Value;     public PostDataParamType Type; } 

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 = new PostData();  byte[] buffer = encoding.GetBytes(pData.GetPostData());  // Set content length of our data oRequest.ContentLength = buffer.Length;  // Dump our buffered postdata to the stream, booyah oStream = oRequest.GetRequestStream(); oStream.Write(buffer, 0, buffer.Length); oStream.Close();  // get the response oResponse = (HttpWebResponse)oRequest.GetResponse(); 

Hope thats clear, i’ve cut and pasted from a few sources to get that tidier.