How can I speed up a UITableView?

Question

I have a UITableView with about 400 cells in 200 sections and it\'s a little sluggish in responding to user interaction (scrolling, selecting cells.) I\'ve made sure the met

Answer 1

The best thing you can do if you're looking to speed up your code is to profile it. There are two reasons for this:

1. You can read about some things that'll improve table performance in general, like using fixed-height cells and re-using cells, and it'll probably help to implement those things (looks like you've already done that). But when it comes to speeding up your code, you really need to know where you app is spending most of its time. It might be that there are a few methods that take a very long time, or a method that's relatively quick but gets called a lot more often than you'd expect.

2. It's impossible to know whether the changes you make in an effort to speed things up truly make a difference unless you have some numbers to measure against. If you can show that your code was spending 80% of its time in one routine and you cut that down to 35%, you know you're making progress.

So, break out Instruments and start measuring. If you can, it's a good idea to measure while you're doing each of the different activities that you want to speed up... do one profiling session while scrolling, one while selecting as many different cells as you can in a fixed period, etc. Don't forget to save the results so you can compare later.