asp.net mvc - Use Ajax.Beginform to send multipart/form-data -

i trying post multipart/form-data web api in view. code of view is:

@{ viewbag.title = "upload"; }  <h2>upload image</h2>  <div> @using (ajax.beginform(null, null, null, new ajaxoptions { httpmethod = "post", url = "http://localhost:59650/api/ingestion/upload", onsuccess = "onsuccess", onfailure = "onfailure", onbegin = "onbegin" }, new { enctype = "multipart/form-data" })) {     <div>         <ol>             <li>                 <input type="file" name="fileupload" />             </li>              <li>                 @html.label("sheetname: ")                 @html.textbox("sheetname")             </li>              <li>                 @html.label("columns: ")                 @html.textbox("columns")             </li>              <li>                 @html.label("file name: ")                 @html.textbox("filename", viewdata["filename"])             </li>         </ol>     </div>      <div>         <input type="submit" name="upload_btn" value="upload" />     </div> } </div>  @section scripts { <script src="~/scripts/jquery.unobtrusive-ajax.min.js"></script> <script type="text/javascript">         function onbegin(xhr) {             xhr.setrequestheader("content-type", "multipart/form-data")         }          function onsuccess(response) {             alert("upload successfully");             //todo:change location             window.location.href = "http://localhost:59650/";         }          function onfailure(response) {             alert("upload failed, please try again");             //todo:change location             window.location.href = "http://localhost:59650/ingestion/uploading";         }      </script> } 

i make content type multipart/form-data in http attributes in beginform helper method in ajax call. however, in api method, got exception saying:

"invalid 'httpcontent' instance provided. not have 'multipart' content-type header 'boundary' parameter.\r\nparameter name: content" 

my web api in controller:

[routeprefix("api/ingestion")] public class valuescontroller : apicontroller {     queueclient senderclient;      [authorize]     /// <summary>     /// post request encrypt , upload file onto azure blob storage.     /// receives value form-data type different values such column, user id, key etc.     /// sends uploaded file details etl service.     /// </summary>     /// <returns>ihttpactionresult either ok or badrequest</returns>     [route("upload")]     [httppost]     public async task<ihttpactionresult> postformdata()     {         var blob = new blobuploadmodel();          try         {             multipartformdatastreamprovider provider = new multipartformdatastreamprovider(path.gettemppath());             //i got exception here             await request.content.readasmultipartasync(provider);             //do sth             ...         }          catch (exception ex)         {             return internalservererror(ex);         }           return ok(blob);     } } 

i confused why getting exception. there other ways send form specific url , handle response accordingly rather using ajax.beginform method?