import 'package:query_string/query_string.dart';

void main() {
  var q = '?page=main&action=front&sid=h985jg9034gj498g859gh495&enc=+Hello%20&empty';
  
  var r = QueryString.parse(q);
  
  print(r['page']); // "main"
  print(r['asdasd']); // null
}