你可能会写一个拉动的服务来自webapi的数据并放入本地SQLite DB。您可以安排该服务以特定间隔执行任务异步。此外，如果服务处于联机状态，您可以尝试同时更新两个数据库。您必须小心处理同步问题。

You probably can write a service that pulls data from webapi and puts into the local SQLite DB. You can schedule that service to do the task async at certain interval. In addition, you can try to update both db at the same time, if the service is online. You have to be careful with synchronizaiton issue.