Upload a list of images of type UIImage (Xamarin)

Question

My app will retrieve a list of all images from a specific folder and attempt to upload them to a server via an API endpoint

Due to the above requirements, an image picker is not suited

Below is the method in the shared code that is passed a list of UIImages (I am trying to get it to work with just ios for now but the same scenario will eventually be applied to Android also)

The below does not work, as when I view the image on the server(AWS), it is in code format. It also says the content type is application/json on the server which I don't understand as I'm setting it to image/png

private async Task UploadImages(List<UIImage> images)
{            
    HttpClient client = new HttpClient();
    var contentType = new MediaTypeWithQualityHeaderValue("image/png");
    client.DefaultRequestHeaders.Accept.Add(contentType);
    client.DefaultRequestHeaders.Add("Id-Token", Application.Current.Properties["id_token"].ToString());

    foreach (var image in images)
    {
        try
        {                                        
            string baseUrl = $"https://********/dev/ferret-test/media/team1/user1/device1/test1.png";             
            client.BaseAddress = new Uri(baseUrl);

            //UploadModel uploadModel = new UploadModel
            //{
            //    image_file = image.AsPNG()
            //};

            byte[] bArray = null;
            Stream pst = image.AsPNG().AsStream();
            using (MemoryStream ms = new MemoryStream())
            {
                ms.Position = 0;
                pst.CopyTo(ms);
                bArray = ms.ToArray();
            }

            //string stringData = JsonConvert.SerializeObject(bArray);
            //var contentData = new StringContent(stringData,
            //System.Text.Encoding.UTF8, "image/png");

            //Byte[] myByteArray = new Byte[imageData.Length];
            //System.Runtime.InteropServices.Marshal.Copy(imageData.Bytes, myByteArray, 0, Convert.ToInt32(imageData.Length));                        

            var postRequest = new HttpRequestMessage(HttpMethod.Put, baseUrl)
            {
                Content = new ByteArrayContent(bArray)
            };

            var response = await client.SendAsync(postRequest);
            response.EnsureSuccessStatusCode();
            string stringJWT = response.Content.ReadAsStringAsync().Result;   
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex);
        }
    }
}       

Answer 1

I archived uploading multiple files to the server by using the following snippet, you can give it a try...

foreach (SQLiteAccess.Tables.Image image in images.OrderByDescending(x => x.Id)) //Here is the collection of all the file at once (Documents + Images)
{
      int documentId = UploadImageToServerAndroid(image).Result;
      // My other code implementation
      .
      .
      .
}

private async Task<int> UploadImageToServerAndroid(SQLiteAccess.Tables.Image image)
       {
           int documentId = 0;

           if (!Admins.ConnectedToNetwork()) return documentId;

           MyFile = FileSystem.Current.GetFileFromPathAsync(image.Path).Result;

           if (MyFile == null) return documentId;
         
           Stream stream = MyFile.OpenAsync(FileAccess.Read).Result;

           byte[] byteArray;
           byteArray = new byte[stream.Length];
           stream.Read(byteArray, 0, (int)stream.Length);
           
           if( !image.IsDocument )
           {
               try
               {
                   byteArray = DependencyService.Get<IImageUtilities>().CompressImage(byteArray); //Its custom code to compress the Image.
               }
               catch (Exception ex)
               {
                   UoW.Logs.LogMessage(new LogDTO { Message = ex.Message, Ex = ex });
               }
           }
           string url = "Your URL";
           using (HttpClient client = new HttpClient(new RetryMessageHandler(new HttpClientHandler())))
           {
               try
               {
                   client.DefaultRequestHeaders.Add(Properties.Resources.Authorization, Sessions.BearerToken);
                   client.DefaultRequestHeaders.Add("DocumentSummary", image.Comment);
                   client.DefaultRequestHeaders.Add("DocumentName", Path.GetFileName(image.Path));
                   MultipartFormDataContent multiPartContent = new MultipartFormDataContent();
                   ByteArrayContent byteContent = new ByteArrayContent(byteArray);
                   byteContent.Headers.ContentType = MediaTypeHeaderValue.Parse("image/jpeg");
                   multiPartContent.Add(byteContent, "image", Path.GetFileName(image.Path));
                   HttpResponseMessage response = await client.PostAsync(url, multiPartContent);
                   if (response.IsSuccessStatusCode && response.Content != null)
                   {
                       string jsonString = response.Content.ReadAsStringAsync().Result;
                       DocumentDTO result = JsonConvert.DeserializeObject<DocumentDTO>(jsonString);
                       documentId = result.DocumentId;
                   }
               }
               catch(Exception ex)
               {
                   UoW.Logs.LogMessage( new LogDTO { Message = ex.Message, Ex = ex });
                   return documentId;
               }
           }
           return documentId;
       }

If documentid is 0(if something went wrong, for any of reason), it's marked as not uploaded & will try to upload it again when the internet is available.

If you need some more help, you can ask...:)