UITableView Not Respecting heightForHeaderInSection/heightForFooterInSection?

In a "grouped" UITableView on the iPhone it will still render a minimum height for header and footer, effectively ignoring your code to set it to zero. It is not linked to the XIB default.

This is because a zero height section header or footer would look very odd. Therefore Apple has decreed that a header height cannot be set to 0. And therefore multiple "empty" sections will render oddly as per your screenshot.

I'm afraid it's all because you're going the wrong way about clearing the header size when there are no data rows; instead you should not be calling any methods for empty sections. It is a bad technique because essentially the iPhone is having to call more methods than it ought to, and also you render more headers than you want to (usually - sometimes people want to leave the blank headers there, for example for drag and drop).

So, for example, let's imagine that you have a number of sections, but only some of them have more than one row in (perhaps based on user settings/filters).

The wrong way of implementing it is:

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
  return totalNumberOfPossibleSections;
}

and then for each section you have no result for:

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
  if (![section hasRow]) return 0;
}

and

- (CGFloat)tableView:(UITableView *)tableView heightForFooterInSection:(NSInteger)section {
  if (![section hasRow]) return 0.0f;
}

The correct way of implementing it is:

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
  return numberOfSectionsWhichHaveAtLeastOneRowInThem;
}

and then each section will have at least one result. That way, sections with no data aren't even rendered, methods aren't even called for them. Note: my two variable names are made up to convey what they'll contain! They're not special Apple variables...

Hope that helps!

It appears that the table respects tableView:heightForHeaderInSection: only if tableView:viewForHeaderInSection: is not nil, or if tableView:titleForHeaderInSection: is not nil or @"". The same is true respectively for footer heights.

So assuming you don't have any section header views or titles, just add this to your table delegate:

- (UIView*)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section {
  return [[[UIView alloc] initWithFrame:CGRectZero] autorelease];
}

This is a bit tricky, as 0.0f value is not accepted. but anything close enough to zero will do the trick. If You decide not to be pixel perfect and want the round numbers, then 1.0f will do almost the same, as 1px difference in height will be fairly noticable.

-(CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section{
    if(section == 1 )
        return 0.000001f;
    else return 44.0f; // put 22 in case of plain one..
}

-(CGFloat)tableView:(UITableView *)tableView heightForFooterInSection:(NSInteger)section{
    return 0.000001f; //removing section footers
}