Google Drive API v3 file upload using C# for UWP

googledrive.cs

public static async Task<File> UploadAsync(DriveService driveService, IList<string> parents, StorageFile file)
        {
            // Prepare the JSON metadata
            string json = "{\"name\":\"" + file.Name + "\"";
            if (parents.Count > 0)
            {
                json += ", \"parents\": [";
                foreach (string parent in parents)
                {
                    json += "\"" + parent + "\", ";
                }
                json = json.Remove(json.Length - 2) + "]";
            }
            json += "}";
            Debug.WriteLine(json);

            File uploadedFile = null;
            try
            {
                BasicProperties prop = await file.GetBasicPropertiesAsync();
                ulong fileSize = prop.Size;
                
                // Step 1: Start a resumable session
                HttpWebRequest httpRequest = (HttpWebRequest)WebRequest.Create("https://www.googleapis.com/upload/drive/v3/files?uploadType=resumable");
                httpRequest.Headers["Content-Type"] = "application /json; charset=UTF-8";
                httpRequest.Headers["Content-Length"] = json.Length.ToString();
                httpRequest.Headers["X-Upload-Content-Type"] = file.ContentType;
                httpRequest.Headers["X-Upload-Content-Length"] = fileSize.ToString();
                httpRequest.Headers["Authorization"] = "Bearer " + ((UserCredential)driveService.HttpClientInitializer).Token.AccessToken;
                httpRequest.Method = "POST";

                using (System.IO.Stream requestStream = await httpRequest.GetRequestStreamAsync())
                using (System.IO.StreamWriter streamWriter = new System.IO.StreamWriter(requestStream))
                {
                    streamWriter.Write(json);
                }

                // Step 2: Save the resumable session URI
                HttpWebResponse httpResponse = (HttpWebResponse)(await httpRequest.GetResponseAsync());
                if (httpResponse.StatusCode != HttpStatusCode.OK)
                    return null;

                // Step 3: Upload the file
                httpRequest = (HttpWebRequest)WebRequest.Create("https://www.googleapis.com/upload/drive/v3/files?uploadType=resumable&upload_id=" + httpResponse.Headers["x-guploader-uploadid"]);
                httpRequest.Headers["Content-Type"] = file.ContentType;
                httpRequest.Headers["Content-Length"] = fileSize.ToString();
                httpRequest.Method = "PUT";

                using (System.IO.Stream requestStream = await httpRequest.GetRequestStreamAsync())
                using (System.IO.FileStream fileStream = new System.IO.FileStream(file.Path, System.IO.FileMode.Open))
                {
                    await fileStream.CopyToAsync(requestStream);
                }

                httpResponse = (HttpWebResponse)(await httpRequest.GetResponseAsync());
                if (httpResponse.StatusCode != HttpStatusCode.OK)
                    return null;

                // Try to retrieve the file from Google
                FilesResource.ListRequest request = driveService.Files.List();
                if (parents.Count > 0)
                    request.Q += "'" + parents[0] + "' in parents and ";
                request.Q += "name = '" + file.Name + "'";
                FileList result = request.Execute();
                if (result.Files.Count > 0)
                    uploadedFile = result.Files[0];
            }
            catch (Exception ex)
            {
                Debug.WriteLine(ex.Message);
            }

            return uploadedFile;
        }

Thank you very much for your help :)

I was able to use the Google Drive API successfully to upload files but I noticed something strange,

I tried to upload a file in the same way to a folder in Share Drive and received an error that the ID of the folder was not successfully found. (The service account was shared in the folder)

Do you have any idea why it would work on a personal Drive account and not on a Share Drive??

In terms of the Google Drive API, is there any difference between a personal Drive account and a Share Drive account??