问题
As the design of table views using the grouped style changed considerably with iOS 7, I would like to hide (or remove) the first section header. So far I haven't managed to achieve it.
Somewhat simplified, my code looks like this:
- (CGFloat) tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section
{
if (section == 0)
return 0.0f;
return 32.0f;
}
- (UIView*) tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section
{
if (section == 0) {
UIView* view = [[UIView alloc] initWithFrame: CGRectMake(0.0f, 0.0f, 640.0f, 0.0f)];
return view;
}
return nil;
}
- (NSString*) tableView:(UITableView *) tableView titleForHeaderInSection:(NSInteger)section
{
if (section == 0) {
return nil;
} else {
// return some string here ...
}
}
If I return a height of 0, the other two methods will never be called with the section index 0. Yet an empty section header is still drawn with the default height. (In iOS 6, the two methods are called. However, the visible result is the same.)
If I return a different value, the section header gets the specified height.
If I return 0.01, it's almost correct. However, when I turn on "Color Misaligned Images" in the simulator, it marks all table view cells (which seems to be a logical consequence).
The answers to the question UITableView: hide header from empty section seem to indicate that some people were successful in hiding the section header. But it might apply to the plain style (instead of the grouped one).
The best compromise so far is returning the height 0.5, resulting in a somewhat thicker line below the navigation bar. However, I'd appreciate if somebody knows how the first section header can be completely hidden.
Update
According to caglar's analysis (https://stackoverflow.com/a/19056823/413337), the problem only arises if the table view is contained in a navigation controller.
回答1:
I have a workaround that seems reasonably clean to me. So I'm answering my own question.
Since 0 as the first section header's height doesn't work, I return 1. Then I use the contentInset to hide that height underneath the navigation bar.
Objective-C:
- (CGFloat) tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section
{
if (section == 0)
return 1.0f;
return 32.0f;
}
- (NSString*) tableView:(UITableView *) tableView titleForHeaderInSection:(NSInteger)section
{
if (section == 0) {
return nil;
} else {
// return some string here ...
}
}
- (void) viewDidLoad
{
[super viewDidLoad];
self.tableView.contentInset = UIEdgeInsetsMake(-1.0f, 0.0f, 0.0f, 0.0);
}
Swift:
override func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
return section == 0 ? 1.0 : 32
}
override func viewDidLoad() {
super.viewDidLoad()
tableView.contentInset = UIEdgeInsets(top: -1, left: 0, bottom: 0, right: 0)
}
回答2:
This is how to hide the first section header in UITableView (grouped style).
Swift 3.0 & Xcode 8.0 Solution
The TableView's delegate should implement the heightForHeaderInSection method
Within the heightForHeaderInSection method, return the least positive number. (not zero!)
func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat { let headerHeight: CGFloat switch section { case 0: // hide the header headerHeight = CGFloat.leastNonzeroMagnitude default: headerHeight = 21 } return headerHeight }
回答3:
The answer was very funny for me and my team, and worked like a charm
- In the Interface Builder, Just move the tableview under another view in the view hierarchy.
REASON:
We observed that this happens only for the First View in the View Hierarchy, if this first view is a UITableView. So, all other similar UITableViews do not have this annoying section, except the first. We Tried moving the UITableView out of the first place in the view hierarchy, and everything was working as expected.
回答4:
Use this trick for grouped type tableView
Copy paste below code for your table view in viewDidLoad method:
tableView.tableHeaderView = [[UIView alloc] initWithFrame:CGRectMake(0.0f, 0.0f, tableView.bounds.size.width, 0.01f)];
回答5:
this way is OK.
override func tableView(tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
if section == 0 {
return CGFloat.min
}
return 25
}
override func tableView(tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
if section == 0 {
return nil
}else {
...
}
}
回答6:
I just copied your code and tried. It runs normally (tried in simulator). I attached result view. You want such view, right? Or I misunderstood your problem?
回答7:
Swift3 : heightForHeaderInSection works with 0, you just have to make sure header is set to clipsToBounds.
func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
return 0
}
if you don't set clipsToBounds hidden header will be visible when scrolling.
func tableView(_ tableView: UITableView, willDisplayHeaderView view: UIView, forSection section: Int) {
guard let header = view as? UITableViewHeaderFooterView else { return }
header.clipsToBounds = true
}
回答8:
Update[9/19/17]: Old answer doesn't work for me anymore in iOS 11. Thanks Apple. The following did:
self.tableView.sectionHeaderHeight = UITableViewAutomaticDimension;
self.tableView.estimatedSectionHeaderHeight = 20.0f;
self.tableView.contentInset = UIEdgeInsetsMake(-18.0, 0.0f, 0.0f, 0.0);
Previous Answer:
As posted in the comments by Chris Ostomo the following worked for me:
- (CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section
{
return CGFLOAT_MIN; // to get rid of empty section header
}
回答9:
Here is how to get rid of the top section header in a grouped UITableView, in Swift:
tableView.tableHeaderView = UIView(frame: CGRect(x: 0, y: 0, width: 0, height: CGFloat.leastNormalMagnitude))
回答10:
In Swift 4.2 and many earlier versions, instead of setting the first header's height to 0 like in the other answers, you can just set the other headers to nil. Say you have two sections and only want the second one (i.e., 1) to have a header. That header will have the text Foobar:
override func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
return section == 1 ? "Foobar" : nil
}
回答11:
Try this if you want to remove all section header completely
func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
return CGFloat.leastNormalMagnitude
}
func tableView(_ tableView: UITableView, heightForFooterInSection section: Int) -> CGFloat {
return CGFloat.leastNormalMagnitude
}
回答12:
I can't comment yet but thought I'd add that if you have a UISearchController on your controller with UISearchBar as your tableHeaderView, setting the height of the first section as 0 in heightForHeaderInSection does indeed work.
I use self.tableView.contentOffset = CGPointMake(0, self.searchController.searchBar.frame.size.height); so that the search bar is hidden by default.
Result is that there is no header for the first section, and scrolling down will show the search bar right above the first row.
回答13:
easiest by far is to return nil, or "" in func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? for a section where you do not wish to display header.
来源：https://stackoverflow.com/questions/19056428/how-to-hide-first-section-header-in-uitableview-grouped-style