Why is there extra padding at the top of my UITabl

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?

Answer 1

I'm assuming that is just part of the new UITableViewStyleGrouped styling. It is in all grouped table views and there doesn't seem to be any direct way to control that space.

If that space is being represented by a UIView, it would be possible to search through all the subviews of the UITableView to find that specific view and edit it directly. However, there is also the possibility that that space is just a hardcoded offset before headers and cells start and there won't be any way to edit it.

To search through all subviews (I would run this code when the table has no cells, to make it a little easier to read the output):

- (void)listSubviewsOfView:(UIView *)view {

    // Get the subviews of the view
    NSArray *subviews = [view subviews];

    // Return if there are no subviews
    if ([subviews count] == 0) return;

    for (UIView *subview in subviews) {

        NSLog(@"%@", subview);

        // List the subviews of subview
        [self listSubviewsOfView:subview];
    }
}

Answer 2

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.

Answer 3

I played around with it a bit more and it seems like this is a side-effect of setting the tableView's tableHeaderView = nil.

Because my tableView has a dynamically appearing tableHeaderView, when I need to hide the tableHeaderView, instead of doing self.tableView.tableHeaderView = nil;, I do:

self.tableView.tableHeaderView = [[UIView alloc] initWithFrame:CGRectMake(0.0f, 0.0f, self.tableView.bounds.size.width, 0.01f)];

I like this solution better than setting a somewhat arbitrary contentInset.top because I use the contentInset.top dynamically as well. Having to remember to remove an extra 35px whenever I recalculate contentInset.top is tedious.

Answer 4

Swift: iOS I had tableview on scroll view .. when I was click "Back" on the same screen. Scroll view take more space on top.. to solve this I have used :

 self.automaticallyAdjustsScrollViewInsets = false

A Boolean value that indicates whether the view controller should automatically adjust its scroll view insets. Default value is true, which allows the view controller to adjust its scroll view insets in response to the screen areas consumed by the status bar, navigation bar, and toolbar or tab bar. Set to false if you want to manage scroll view inset adjustments yourself, such as when there is more than one scroll view in the view hierarchy.

Answer 5

override func viewWillAppear(animated: Bool) {
        self.edgesForExtendedLayout = UIRectEdge.None

 //  OR

self.sampleTableView.contentInset = UIEdgeInsetsMake(-64, 0, 0, 0);

   //OR

 self.automaticallyAdjustsScrollViewInsets = false
        }

Answer 6

Uncheck "Adjust Scroll View insets"