Hi everybody,

I am wondering if someone has a routine to figure out file's type based on either its content or its filename. In my routine I have

 var streamProvider = new MultipartMemoryStreamProvider();
                    streamProvider = await Request.Content.ReadAsMultipartAsync(streamProvider);

                    foreach (
                        var item in
                        streamProvider.Contents.Where(c => !string.IsNullOrEmpty(c.Headers.ContentDisposition.FileName))
                    )
                    {
                        using (Stream stFileSource = new MemoryStream(await item.ReadAsByteArrayAsync()))                     {
                            byte[] fileBytes;
                            
                            fileBytes = new Byte[stFileSource.Length];
                            stFileSource.Read(fileBytes, 0, Convert.ToInt32(stFileSource.Length));
                            FileUploadResult file = new FileUploadResult()
                            {
                                FileName = item.Headers.ContentDisposition.FileName,
                                Content = fileBytes,
                                Key = Guid.NewGuid().ToString()
                            };

and in my FileUploadResult I added string property Type which I'd like to somehow discover from either content or extension (e.g. Image, PDF, Document, Excel - I think I limited my front-end to only those types).

The other question I have - is there a way to save information between different API calls? I'm trying right now a property of my API controller to hold list of files, but I'm not certain it will work - what is the normal way in MVC to persist information between API calls without a need to send information back to the page?

Thanks in advance.