JSON input for Upload function in WebApi C# - asp.net-web-api

Question

I have an upload function in my WebApi C# code, which works fine with Query string parameters. I will be passing the file in Rest client using multi-Form data and it works completely fine.
Now I have to change the parameters to JSON format, doing so the request is not hitting the controller. Can anyone please help me here.
public ReturnMsg UploadDocument(string fileName, string fileSize, string ApplNo, string DocId, string DocSize,string resumeId,string DependId)
{
ReturnMsg objReturnMsg = new ReturnMsg ();
HttpResponseMessage response = new HttpResponseMessage();
var httpRequest = HttpContext.Current.Request;
Stream stream = null;
if (httpRequest.Files.Count > 0)
{
foreach (string file in httpRequest.Files)
{
var postedFile = httpRequest.Files[file];
var filePath = string.Empty;
stream = postedFile.InputStream;
}
objReturnMsg = Bll.UploadFiles(fileName, fileSize, DocId, DocSize,DependId,stream);
}
else
{
objReturnMsg.Status = "F";
objReturnMsg.ReturnMessage = "Please Upload a Valid Form";
}
return objReturnMsg;
}
I want it in
public ReturnMsg UploadDocument(DocDetails docDet)
{
ReturnMsg objReturnMsg = new ReturnMsg ();
HttpResponseMessage response = new HttpResponseMessage();
var httpRequest = HttpContext.Current.Request;
Stream stream = null;
if (httpRequest.Files.Count > 0)
{
foreach (string file in httpRequest.Files)
{
var postedFile = httpRequest.Files[file];
var filePath = string.Empty;
stream = postedFile.InputStream;
}
objReturnMsg = Bll.UploadFiles(docDet.fileName, docDet.fileSize, docDet.DocId, docDet.DocSize,docDet.DependId,stream);
}
else
{
objReturnMsg.Status = "F";
objReturnMsg.ReturnMessage = "Please Upload a Valid Form";
}
return objReturnMsg;
}