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I have been trying to troubleshoot glitchy table view scrolling performance. Running it through Instrument's Time Profiler shows that decent amount of time is spent setting NSAttributedString to UILabel. Is this a known problem? If so, is there a work around?

I see some reports that creation of NSAttributedString got really slow on iOS8 and improved a bit on iOS9, but is it also slow setting it to a containing UI element? NSAttributedString performance is worse under iOS 8

Below is the screen shot from my profiling. Note that view model doesn't dynamically create attributed strings, so the cost you see is purely from assignment. Of course, UILabel can be performing expensive operations, which I don't know how to get around.

enter image description here

I appreciate any help.

Community
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dfujiwara
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1 Answers1

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At the top of this method you can check cell is configured only once. The cell is reusing while scrolling so you can configure cell with the same view model more than once, that don't needed. Code will looks like this

guard self.viewModel !== viewModel else { return }

or compare viewModel.profileInformation.attributedText with value at the label.

Ivan Vavilov
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