private void btnFolder_Click(object sender, RoutedEventArgs e)
        {
            IFileChooser fileChooser = new WpfFileChooser();

            var result = fileChooser.OpenFolder();

            if (result.Result.Value)
            {
                MessageBox.Show("1 folder selected." + System.Environment.NewLine + result.SelectedPath);
            }
            else
            {
                MessageBox.Show("Operation canceled");
            }
        }
        private void btnFiles_Click(object sender, RoutedEventArgs e)
        {
            IFileChooser fileChooser = new WpfFileChooser();

            var result = fileChooser.OpenFiles(chkMultipleFileSelection.IsChecked.Value);

            if (result.Result.Value)
            {
                var files = string.Join(System.Environment.NewLine, result.SelectedFiles.Select(f => f.FilePath + " (" + f.FileSize + ")"));
                MessageBox.Show(result.SelectedFiles.Count + " file(s) selected." + System.Environment.NewLine + files);
            }
            else
            {
                MessageBox.Show("Operation canceled");
            }
        }