如果适配器具有2000个以上的对象，则RecyclerView的性能

Question

I have created a list via RecyclerView with more than 2000 items. RecyclerView will recycle controls but the list assigned has more than 2000 objects in it. List might have even 4000 objects as well.

Is it a good idea to have all the objects in the list in memory or there is any other way to manage?

Now if I implement endless scrolling or show loader to load data, it will be added to the list and notifyDataSetChanged(); will be called. But the question remains same to maintain a list of more than 2000 objects.

Suggest better approach for this scenario.

Answer 1

If u initially have 2000 items then by any mean the RecyclerView will keep them in memory so that it can load them. But if ur getting these item from network then as u said u can implement infinite scroll, load the item from ur web service as needed and add them to ur list.

Answer 2

i am currently going through same scenario but my data set is way big it has currently 2600 items but i have prepared my list to add nearly 100k items in it, the way i am dealing with this is that:

I am using .json file in res/raw for my app with the items and loading all items in a List, Ok. Now instead of throwing this List with all items directly to the adapter what i opted to do is to have another List in which i will add items little by little and populate RecyclerView using load more mechanism. And when you have loaded whole items in RV simply clear the previously fetched list to clear memory.

Many people suggest to use Web Service or API and fetch data repeatedly which is, imo, a bogus approach, because if your app, suppose has 10,00,0000 users and at a time 450,000 user are online and they all doing fetch via load more what will it do to WebServer and above all all requests will eventually fetch data from DB (so many hits to DB.... is always considered as worst approach) so if going this way you also need to take care of API mechanism like implementing middleware data request look up to avoid taking users' request to DB every time and return them data from Web Server layer if the request of user is already made and is cached in this layer (definitely, difficult task but this is how it is being used these days).

If you(or anyone) finds better approach kindly discuss. Hope i helped somehow.

Answer 3

If the object is too heavy/ or you fetching it from server, then better to manage virtual paging. Let define your page size is 100, in onBind put a check that if it has reached 70%(showing 70th row) of your list then it will make a call to fetch another 100.

And don't worry about RecyclerView/ListView, they have no problem with the list size, because the maximum number of rows created by RecyclerView or ListView is the maximum rows you can view on the page whatever the size of your list is.

Hope it will help.. :)