UITableView delete section - header stays visible - ios

Question

After using [UITableView deleteSections:withRowAnimation:] on a section which is out of view - the section header remains visible.
On this image, we see the visible part of the tableview
On the next image, we see the whole tableview - AISLE 2 is hidden until the user scrolls down, it contains only one row:
When I scroll down and delete the last row, AISLE 2 section header remains visible, even though I used deleteSections. if I delete a row from AISLE 1, the section header remains on the same place, and by scrolling down I can still see it.
Furthermore, when trying to scroll down so that AISLE 2 header is in the view, the UI acts as AISLE2 is NOT part of the tableview, and immediately scrolls me back up. Which means - this is a garbage view that is obviously not part of the table, since I removed it. for some reason, iOS doesn't remove this view, but de-associates it from the table.
Any ideas?

Answer 1

Try [tableview reload] with making numberofsections as 1.

Answer 2

Where is your data coming from and how do you know how many sections there are at the start? I think your problem can easily be resolved by explaining this.
It looks like you may have a multidimentional nsmutablearray where each index is an aisle and each object contains the products for that isle? Or you may have a different array for each aisle?
When you delete a cell, simply check how many cells are left, and call [self.tableView reloadData];
For (hypothetical) example;
if you have arrays of your Aisles:
NSMutableArray *aisleOne = [[NSMutableArray alloc] initWithObjects:#"Product1", #"Product2", nil];
NSMutableArray *aisleTwo = [[NSMutableArray alloc] initWithObjects:#"Product1", #"Product2", nil];
NSMutableArray *aisleThree = [[NSMutableArray alloc] initWithObjects:#"Product1", #"Product2", nil];
NSMutableArray *aisleFour = [[NSMutableArray alloc] initWithObjects:#"Product1", #"Product2", nil];
and you add them to one array:
NSMutableArray *aisleArray = [[NSMutableArray alloc] initWithObjects:aisleOne, aisleTwo, aisleThree, aisleFour, nil];
then, call this code when you delete a cell. It will remove all empty Aisles from the aisleArray (which needs to be globally defined):
NSMutableArray *tempArray = [[NSMutableArray alloc] initWithArray:aisleArray];
for (int i=0; i<[tempArray count]; i++) {
if ([[tempArray objectAtIndex:i] count] == 0) {
[aisleArray removeObjectAtIndex:i];
}
}
[self.tableView reloadData];
For this to work, these two methods should be:
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return [aisleArray count];
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return [[aisleArray objectAtIndex:section] count];
}
(untested)

Answer 3

Just get the table haderview for that section and remove it from it's superview and tableView is not managing it.
UIView *mysteriousView = [tableView headerViewForSection:indexPath.section];
[tableView deleteSections:[NSIndexSet indexSetWithIndex:indexPath.section] withRowAnimation:UITableViewRowAnimationAutomatic];
[mysteriousView removeFromSuperview];
Hope this helps!

Answer 4

Few yers later I'm facing same issue... Deleting last section doesn't remove last section header from table view.
I noticed however that the remaining header has frame exactly just below normal table view content.
So the workaround (in swift but you can easily translate it to Objective C) that worked for me is something like this:
DispatchQueue.main.async {
let unwantedViews = self.tableView.subviews.filter{ $0.frame.minY >= self.tableView.contentSize.height}
unwantedViews.forEach{ $0.isHidden = true }
}