Slow loading of UITableView. How know why?


Slow loading of UITableView. How know why?



I have a UITableView that show a long list of data. Use sections and follow the sugestion of http://stackoverflow.com/questions/695814/how-solve-slow-scrolling-in-uitableview .

The flow is load a main UITableView & push a second selecting a row from there.

However, with 3000 items take 11 seconds to show. I suspect first from the load of the records from sqlite (I preload the first 200). So I cut it to only 50.

However, no matter if I preload only 1 or 500, the time is the same.

The view is made from IB and all is opaque.

I run out of ideas in how detect the problem. I run the Instruments tool but not know what to look.

Also, when the user select a cell from the previous UITable, no visual feedback is show (ie: the cell not turn selected) for a while so he thinks he not select it and try several times. Is related to this problem.

What to do?

NOTE: The problem is only in the actual device:

  • iPod Touch 2d generation
  • Using fmdb as sqlite api
  • Doing the caching in viewDidLoad
  • Using NSDictionary for the caching
  • Using a NSAutoreleasePool for the caching part.
  • Only caching the row ID & mac 4 fields necesary to show the cell data
  • UIView made with interface builder, SDK 2.2.1
  • Instruments say I use 2.5 MB in the device

UITableView Animation Headache

1:

iPhone OpenGL ES incorrect alpha blending
The -[FMResultSet next] call must be a very expensive call to make, depending on the data that's receive ting loaded. Does a NSURLConnection retain its delegate? It'd during this call this sqlite is actually going to the database, finding the next row to return, and giving you back the appropriate fields. Which button was tapped… iPhone and Obj-C question It's not just an enumerator.. Connection You might want to consider pre-caching all of the data before actually displaying the table. Can UILabel's drawTextInRect method be overridden to change the size of UILabel's text? This means this you would did all of your FMDB calls before the table receive s shown on the screen.. Attaching another modem to an iPhone or gPhone If this takes too long, you might want to show the tableview with its initial rows, and then use NSOperations or just a second thread to load the data in the background and cache it this way.. Making a UITableView scroll when text field is selected

2:

Without seeing any code, I think I would be inclined to think this you need to index you tables. . You should see an enormous speed up by adding an index on the attrialthough es you query on. You must did this by using the CREATE INDEX SQL command..


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