CODEWITHSUNDEEP
iosswiftuitableview
Neo Z
Neo Z

Reputation: 47

iOS: performance when there are thousands of sections in UITableView

I have thousands of sections in TableView,and I use titleForHeaderInsection to give each of them a title.But I find that when the TableView is initialized, this method will be called thousands times to give every sections a title. Is that means I should set several sections each time?

Upvotes: 2

Views: 496

Answers (3)

pedrouan
pedrouan

Reputation: 12910

No, you don't have to.

A memory is optimised for such occasions, so if your data source is properly set and contains data regardless its size, UI should handle it safely.

UITableView in iOS app, for example, is rendering just those cells, that are displayed at current time. So for example the common tableview on the iPhone 6 is displaying about 15 rows at a time.

And as a user, when you are scrolling down (or up) the table view, each time before the certain cell is displayed, the method cellForRow is called and takes data from your data source.

This also works for sections.

But, if your data don't have to be stored in the App bundle, the best way would be to get source data asynchronously, so for example you get 30 rows from data from server, after launching the app. Then if you reach (by scrolling) 30th row, your app will request more data from server and updates the table. So user, that won't scroll your tableView, will not download all data and will not use big data transfer.

As a conclusion I would mention, that for all situations, the smaller data source, the better for performance of your app.

Upvotes: 2

jiten
jiten

Reputation: 137

Go through life cycle of Uitableview datasource methods as each and every method will get called for each section and row. So it is completely fine if section method is called thousand times. If you have any issue for it then add a paging like load first 10 sections and then other 10 sections and go on.

Upvotes: 0

Shobhakar Tiwari
Shobhakar Tiwari

Reputation: 7892

Tableview works on concept of reusability so only few which are visible are created and after that rest all are reused so no need to bother about it .

Rest refer to this link : Apple official link : https://developer.apple.com/library/ios/documentation/UserExperience/Conceptual/TableView_iPhone/TableViewCells/TableViewCells.html

Upvotes: 1

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