在其他活动中将项目添加到RecyclerView

Question

I'm working on a simple application, but I got stuck with the Android design architecture. In my main Activity, I have a RecyclerView which shows a list of items. When I click the floating action button in the main Activity, a new Activity (input Activity) is started where a new item to the RecyclerView must be added.

What is the best way to do this?

• I could share the ViewModel of the main Activity with the input Activity. But when I add an item to this shared ViewModel, the RecyclerView is not automatically updated.
• I could create a result Intent in the input Activity. But there is no possibility to include a new Item() object in this Intent.

Since I'm new to Android application development, I'm not sure how to do this.

Answer 1

1. Save data of Input activity in sqlite.
2. Save a boolean flag on shared preference indicating data has changed. You might use another integer(or string, depending on you implementation) for saving sqlite primary key of the newly added input.
3. Exit Input Activity
4. Inside onResume() of Main activity, check if data is added, if added, grab its id and values.