Future requestPermission() async {

    // 申请权限

    Map<PermissionGroup, PermissionStatus> permissions =

        await PermissionHandler().requestPermissions([PermissionGroup.storage]);

    // 申请结果

    PermissionStatus permission = await PermissionHandler()

        .checkPermissionStatus(PermissionGroup.storage);

    if (permission == PermissionStatus.granted) {

      print("权限申请通过");

    } else {

      print("权限申请通过");

    }

  }

}