UITableView reloadSections/reloadData: header view becomes blank

Question

I have a UITableView with some sections, each has its own header view. When user taps on the header view of a section, all rows of that section will collapse. What i do is, I set the number of row of that section to 0, and then call :

[self.tableView reloadSections:sections withRowAnimation:UITableViewRowAnimationBottom];

Everything works as expected, except one thing : the header view of the section becomes white blank. When i scroll the table, then the header becomes normal again.

So i guess there's some problem with the drawing of the table.

One funny thing is, if i use UITableViewRowAnimationFade instead, then even when i scroll the table, the header is still white blank.

When I update just ONE section there is also no problem - when I update more than one section the problem occurs.

If i use

[self.tableView reloadData]

instead, then everything works fine.

The reason i use

[self.tableView reloadSections:sections withRowAnimation:UITableViewRowAnimationBottom];

is because i want animation.

Wrapping with beginUpdates / endupdates does not work.

score 48 · Answer 1 · edited May 23 '17 at 12:26

48

I realize that it's a LONG time since this question was posed but I think all of the answers given below are incorrect.

I had the same problem (with someone else's code) and was about to be fooled by this post when I realized that the code was not doing it's reuse of the table header correctly. The header disappearing was because the code was only supplying a UIView, not a UITableViewHeaderFooterView, registered correctly and set up for reuse.

Have a look at the answer here: How to use UITableViewHeaderFooterView?

My blank headers went away when I set up a reusable header.

edited May 23 '17 at 12:26

Community

1
1

answered Jan 20 '15 at 22:16

Darren

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13
23

Nice catch - seems so obvious now... :) – NSTJ Nov 08 '16 at 23:56
@GeneCode the answer by Raz explains the re-use process fairly well. – Darren Jan 23 '17 at 22:00
1

@Darren Thanks for this answer. I added some Swift notes below – Zack Shapiro Apr 07 '17 at 21:00
This works for me in iOS 12! I had a custom `UITableViewCell` with Xib-File as Header. Funny thing is that I left the Xib as it was and just made the custom class subclass of `UITableViewHeaderFooterView` and changed the register and dequeuing functions for the table view and it was working :) – heyfrank Oct 10 '18 at 12:06
Good solution! You save my day. Thanks – Yano Feb 13 '20 at 14:29

score 3 · Answer 2 · answered Apr 07 '17 at 20:59

3

In Swift:

You need to create a class that's a subclass of UITableViewHeaderFooterView and register it to the table view. Then in viewForHeaderInSection, you do let header = tableView.dequeueReusableHeaderFooterView(withIdentifier: "HeaderView") as! YourHeaderView, similar to what you do for UITableViewCells. Then return that header.

The deceptive thing is the function calls for a return of UIView? when it really needs a dequeuedReusableHeaderFooterView or reloadData will cause it to disappear

answered Apr 07 '17 at 20:59

Zack Shapiro

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83
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Could you provide a snippet of code for this? I've been struggling with this issue for several days now and you're the only one suggesting this approach (which I think is the correct one) – Mauricio Chirino Mar 10 '18 at 19:55
I forgot to say please – Mauricio Chirino Mar 10 '18 at 19:55

score 1 · Accepted Answer · answered Dec 29 '11 at 10:51

I found a work-around - not very elegant, but it works. Instead of providing a NSIndexSet with more than one section, I call the reloadSections within a for-loop with only one section in each call.

looks like:

    for (Element *eleSection in self.gruppenKoepfe) {
        if ( eleSection.type.integerValue == qmObjectTypeFormularSpalte || eleSection.type.integerValue == qmObjectTypeFormularZeile ) {
            [self.tableView reloadSections:[NSIndexSet indexSetWithIndex:nCount] withRowAnimation:UITableViewRowAnimationFade];
        }
        nCount ++;
    }

https://stackoverflow.com/questions/30149551/tableview-section-headers-disappear-swift please check this. — Sagar Daundkar, Apr 24 '18 at 10:12

score 0 · Answer 4 · answered Jun 07 '13 at 16:15

I was having a similar problem, except I was trying to delete/insert sections, and I found that keeping a strong property pointing to the entire header view (i.e. not just a subview) stopped it disappearing during section updates.

e.g. Property and instantiation

@property (nonatomic, strong) UIView *headerView;

-(UIView *)headerView {
  if ( !_headerView ) {
    _headerView = [[UIView alloc] initWithFrame:CGRectMake(0,0,self.view.bounds.size.width, 300)];
    // add additional view setup, including subviews
  }
  return _headerView;
}

And in tableView:(UITableView *)viewForHeaderInSection:(NSInteger)section:

-(UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section {
    if ( section == theCorrectSection ) {
        return self.headerView;
    }
    return nil;
}

score 0 · Answer 5 · answered Aug 12 '16 at 08:15

0

I had the same issue and it was none of the above. My problem was that i was hidding the first header and for some reason after more then 10 reloads the header at index 2 was set hidden. When i set headerView.hidden = false it was ok.

answered Aug 12 '16 at 08:15

albalilium

1
1

UITableView reloadSections/reloadData: header view becomes blank

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