为什么在 iOS7中 UITableView 风格组合的顶部会有额外的填充

Question

Starting in iOS7, there is additional space at the top of my UITableView's which have a style UITableViewStyleGrouped.

Here is an example:

The tableview starts at the first arrow, there is 35 pixels of unexplained padding, then the green header is a UIView returned by viewForHeaderInSection (where the section is 0).

Can anyone explain where this 35 pixel amount is coming from and how I can get rid of it without switching to UITableViewStylePlain?

转载于:https://stackoverflow.com/questions/18880341/why-is-there-extra-padding-at-the-top-of-my-uitableview-with-style-uitableviewst

Answer 1

I have found the cause of my original bug and created a sample project showcasing it. I believe there is an iOS7 bug.

As of iOS7, if you create a UITableView with the Grouped style, but do not have a delegate set on first layout, then you set a delegate and call reloadData, there will be a 35px space at the top that will never go away.

See this project I made showcasing the bug: https://github.com/esilverberg/TableViewDelayedDelegateBug

Specifically this file: https://github.com/esilverberg/TableViewDelayedDelegateBug/blob/master/TableViewDelayedDelegateBug/ViewController.m

If line 24 is active,

[self performSelector:@selector(updateDelegate) withObject:nil afterDelay:0.0];

there will be an extra 35 px space at the top. If line 27 is active and 24 is commented out,

self.tableView.delegate = self;

no space at the top. It's like the tableView is caching a result somewhere and not redrawing itself after the delegate is set and reloadData is called.