gistfile1.txt

        protected override async void OnNavigatedTo(NavigationEventArgs e)
        {
            base.OnNavigatedTo(e);
            Debug.WriteLine("Debut");
            var file = await SaveAsync(new Uri("Ton ZIP"));

            Debug.WriteLine($"Downloaded : {file.Path}");
        }

        public static async Task<StorageFile> SaveAsync(
        Uri fileUri)
        {
            var fileSavePicker = new FileSavePicker();
            fileSavePicker.DefaultFileExtension = ".zip";
            fileSavePicker.FileTypeChoices.Add(".zip Archive", new List<string> { ".zip" });
            fileSavePicker.SuggestedFileName = "Archive.zip";
            var outputFile = await fileSavePicker.PickSaveFileAsync();
            
            var downloader = new BackgroundDownloader();
            var download = downloader.CreateDownload(
                fileUri,
                outputFile);

            var res = await download.StartAsync();

            return outputFile;
        }