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I have a long text coming from my JSON file but when I click the link from my UITableViewCell to go to my UIViewController page, the UITextView text loads the string content but it does not show the content from the beginning and I have to scroll up all the time.
What I need to do?
I had the same problem, and turns out I had to set the content offset in viewDidLayoutSubviews for it to take effect. I'm using this code to display attributed static text.
- (void)viewDidLayoutSubviews {
[self.yourTextView setContentOffset:CGPointZero animated:NO];
}
SWIFT 3:
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
self.textView.setContentOffset(CGPoint.zero, animated: false)
}
This is the only way that worked for me. I disable the scroll of the UITextView before the view is loaded and then i enable it again:
override func viewWillAppear(_ animated: Bool) {
yourTextView.isScrollEnabled = false
}
override func viewDidAppear(_ animated: Bool) {
yourTextView.isScrollEnabled = true
}
[self.textView scrollRangeToVisible:NSMakeRange(0, 1)];
in viewDidLoad
By Programmatically before loading the content disable the scrolling property of textview
textview.scrollenabled = NO;
And after loading enable the scrolling of textview textview.scrollenabled = YES;
As well check the XIB, always non-check the scrolling enabled of Textview.
The answers for the question Blank space at top of UITextView in iOS 10 provide a much cleaner end user experience.
In viewDidLoad of the view controller containing the text view:
self.automaticallyAdjustsScrollViewInsets = false
Setting textView.setContentOffset(CGPointMake(0,0), animated: false) and some of these other suggestions do work when called in the viewDidLayoutSubviews() but on older devices like iPad 2 and older you will actually see the text get scrolled when the screen is displayed. That is not something you want the end user to see.
I was still having problems after using these solutions. The problem definitely seems to relate to having transparent navigation bars and selecting to automatically adjust content insets on the view controller. If you don't care about your text scrolling underneath the navigation bar then it's best to leave these settings off and constrain the top of your textview to the bottom of the navigation bar, rather than to the top of the viewcontroller.
If like me you wanted it to appear underneath your navigation bar when you scroll down; then the solution that worked for me was to add this.
- (void)viewDidLayoutSubviews
{
[super viewDidLayoutSubviews];
CGFloat offset = self.navigationController.navigationBar.frame.size.height+[UIApplication sharedApplication].statusBarFrame.size.height;
[self.textView setContentOffset:CGPointMake(0, -offset) animated:NO];
}
This just looks for the height of the navigation bar and status bar and adjusts the content offset accordingly.
Note that one downside of this approach is that when the device rotates you'll end up scrolling back to the top.
For me fine works this code:
textView.attributedText = newText //or textView.text = ...
//this part of code scrolls to top
textView.contentOffset.y = -64 //or = 0 if no Navigation Bar
textView.scrollEnabled = false
textView.layoutIfNeeded()
textView.scrollEnabled = true
For scroll to exact position and show it on top of screen I use this code:
var scrollToLocation = 50 //<needed position>
textView.contentOffset.y = textView.contentSize.height
textView.scrollRangeToVisible(NSRange.init(location: scrollToLocation, length: 1))
Setting contentOffset.y scrolls to the end of text, and then scrollRangeToVisible scrolls up to value of scrollToLocation. Thereby, needed position appears in first line of scrollView.
Similar to some other answers, but with the added benefit that you won't cause a scroll to top on subsequent device rotations. Works well in Swift 2.2
/// Whether view has laid out subviews at least once before.
var viewDidLayoutSubviewsAtLeastOnce = false
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
if !viewDidLayoutSubviewsAtLeastOnce {
textView.setContentOffset(CGPoint(x: 0, y: -textView.contentInset.top), animated: false)
}
viewDidLayoutSubviewsAtLeastOnce = true
}
Swift Version
A combination of things will be needed:
1.) Set your outlet
#IBOutlet var textView: UITextView!
2.) In storyboard on View Controller turn off "Adjust Scroll View Insets"
3.) Set content to zero top by adding below to your view controller
override func viewWillLayoutSubviews() {
super.viewWillLayoutSubviews()
myUITextView.setContentOffset(CGPointZero, animated: false)
}
Instead of setting content offset from viewDidLayoutSubviews you can write layoutIfNeeded from viewDidLoad to set the proper position of textview as below:
self.textView.layoutIfNeeded()
self.textView.setContentOffset(CGPoint.zero, animated: false)
Cheers !!
In Swift 2, Xcode 7 solution, to leave scroll Enabled as well as have the text start at the top, this is all you need:
#IBOutlet weak var myUITextView: UITextView!
override func viewWillLayoutSubviews() {
super.viewWillLayoutSubviews()
//start scroll at top of text
myUITextView.scrollRangeToVisible(NSMakeRange(0, 0))
}
Swift 3.0
override func viewWillAppear(_ animated: Bool) {
privacyText.isScrollEnabled = false
}
override func viewDidAppear(_ animated: Bool) {
privacyText.isScrollEnabled = true
}
This worked the best for me! I placed this within viewDidLoad().
//TextView Scroll starts from the top
myTextView.contentOffset.y = 0
Here's another way to do it that always works for me. Objective-C:
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
[self.textView setContentOffset:CGPointZero animated:NO];
}
And in Swift:
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
textView.setContentOffset(CGPointZero, animated: false)
}
Swift version:
override func viewDidLayoutSubviews() {
yourTextView.setContentOffset(CGPointZero, animated: false)
}
add the following function to your view controller class...
Swift 3
override func viewDidLayoutSubviews() {
self.mainTextView.setContentOffset(.zero, animated: false)
}
Swift 2.1
override func viewDidLayoutSubviews() {
self.mainTextView.setContentOffset(CGPointZero, animated: false)
}
Objective C
- (void)viewDidLayoutSubviews {
[self.mainTextView setContentOffset:CGPointZero animated:NO];
}
或者 你在ViewDidAppear 里面加上滚动，这样用户会看到他往上滚动到第一行
in swift 4 with attributed text any of answer does not help me and i combine some answers in topic.
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
uiTextview.isScrollEnabled = false
}
override func viewDidAppear(_ animated: Bool) {
uiTextview.isScrollEnabled = true
uiTextview.setContentOffset(CGPoint.zero, animated: false)
}
Swift 3, 4, 5 solution:
Steps to solve the issue:
Disable the UITextView scroll
set scrollRectToVisible
enable UITextView scroll
Code:
yourTextView.isScrollEnabled = false
let rect:CGRect = CGRect(x: 0, y: 0, width: 1, height: 1)
yourTextView.scrollRectToVisible(rect, animated: false)
yourTextView.isScrollEnabled = true
This Worked for me. Hope that will help!
This is how i did it. I subclassed textview, and:
override func willMoveToSuperview(newSuperview: UIView?) {
self.scrollEnabled = false
}
override func layoutSubviews() {
super.layoutSubviews()
self.scrollEnabled = true
}
From storyboard, select the view controller on which you have you text view placed. In the attributes inspector, uncheck "Adjust Scroll View Insets". That's it.
Put this code on your class
override func viewDidLayoutSubviews() {
self.About_TV.setContentOffset(.zero, animated: false) // About_TV : your text view name)
}
Add code to the viewdidload
self.automaticallyAdjustsScrollViewInsets = NO;
So I want to hide the navbar when scrolling down and bring it back when scrolling up. Hiding it works perfectly with
self.navigationController?.hidesBarsOnSwipe = true
But I expect it to be shown again when scrolling up. I made a test project where the view controller just has a single UICollectionView that covers the whole screen. Then showing the navbar is shown again as expected until I add this line to the viewDidLoad (adding cells to the collection view):
self.collectionView.delegate = self
And this is what the whole view controller looks like
class ViewController: UIViewController,UICollectionViewDataSource, UICollectionViewDelegate {
#IBOutlet var collectionView: UICollectionView!
override func viewDidLoad() {
super.viewDidLoad()
self.collectionView.dataSource = self
self.collectionView.delegate = self
self.collectionView.registerClass(UICollectionViewCell.self, forCellWithReuseIdentifier: "Test")
self.navigationController?.hidesBarsOnSwipe = true
}
func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 3
}
func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
return 1
}
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
return collectionView.dequeueReusableCellWithReuseIdentifier("Test", forIndexPath: indexPath) as UICollectionViewCell
}
func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
return CGSizeMake(300, 300)
}
}
So why does showing the navbar stop working when I add cells to my collection view?
I had the same problem but with a web view.
The problem was that the top constraint of the web view was "Top Layout Guide.Top" , after changing the top constraint to "Superview.Top" the problem was solved.
To expand on Oleg's answer...
If you are using Interface Builder to set a constraint to a view controller's primary view, Xcode defaults to showing options to set the vertical constraint against the top layout guide. However, if you press 'Option', you will see an alternate set of constraints. The constraint for 'Top Space to Container' is what you're looking for.
I had same issue. When I added the code for hiding status bar along with navigation bar, it worked.
- (BOOL)prefersStatusBarHidden {
return self.navigationController.isNavigationBarHidden;
}
I tried setting hidesBarsOnSwipe property to true in my ViewController class in ViewDidLoad function as given below, but it didn't work in handling hiding the navigation bar on swipe-up and unhiding the navigation bar on swipe-down.
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
self.navigationController?.hidesBarsOnSwipe = true
}
}
Setting hidesBarsOnSwipe to true will have effect only if we are using the UITableViewController or UICollectionViewController as main screens, hidesBarsOnSwipe will not work if we have added a UITableView to the UIViewController for displaying the list of data.
Solution
class TestTableViewController: UITableViewController {
override func viewDidLoad() {
super.viewDidLoad()
self.navigationController?.hidesBarsOnSwipe = true
}
}
Hope this answer might help...!
I filed a bug report with Apple and ended up using AMScrollingNavbar instead which works really well and is easy to setup.
As per previous comments - this seems like a bug as of ios 10.3
as you are using a uicollectionview - I draw your attention to some code I re-wrote from APDynamicHeaderTableViewController
https://github.com/aaronpang/APDynamicHeaderTableViewController/issues/4
It's using snapkit https://github.com/SnapKit/SnapKit
(Apologies to all the IB + NSLayout Constraint lovers.)
class APDynamicHeaderTableViewController : UIViewController {
var largeWideSize = CGSize(width: UIScreen.main.bounds.width , height: 285 )
let headerView = APDynamicHeaderView () // Change your header view here
let cellLayout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
var feedCV:UICollectionView!
fileprivate var headerViewHeight:CGFloat = 80 // this will be updated by scrolling
fileprivate var headerBeganCollapsed = false
fileprivate var collapsedHeaderViewHeight : CGFloat = UIApplication.shared.statusBarFrame.height
fileprivate var expandedHeaderViewHeight : CGFloat = 100
fileprivate var headerExpandDelay : CGFloat = 100
fileprivate var tableViewScrollOffsetBeginDraggingY : CGFloat = 0.0
init(collapsedHeaderViewHeight : CGFloat, expandedHeaderViewHeight : CGFloat, headerExpandDelay :CGFloat) {
self.collapsedHeaderViewHeight = collapsedHeaderViewHeight
self.expandedHeaderViewHeight = expandedHeaderViewHeight
self.headerExpandDelay = headerExpandDelay
super.init(nibName: nil, bundle: nil)
}
init () {
super.init(nibName: nil, bundle: nil)
}
required init(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func loadView() {
super.loadView()
self.view.backgroundColor = .green
// Cell Layout Sizes
cellLayout.scrollDirection = .vertical
cellLayout.sectionInset = UIEdgeInsets(top: 0, left: 10, bottom: 0, right: 10)
cellLayout.itemSize = CGSize(width: UIScreen.main.bounds.width, height: 185 + 80)
// Header view
self.view.addSubview(headerView)
headerView.snp.remakeConstraints { (make) -> Void in
make.top.left.equalToSuperview()
make.width.equalToSuperview()
make.height.equalTo(headerViewHeight)
}
// CollectionView
feedCV = UICollectionView(frame: .zero, collectionViewLayout: cellLayout)
self.view.addSubview(feedCV)
self.feedCV.snp.remakeConstraints { (make) -> Void in
make.top.equalTo(headerView.snp.bottom) // this is pegged to the header view which is going to grow in height
make.left.equalToSuperview()
make.width.equalToSuperview()
make.bottom.equalToSuperview()
}
feedCV.backgroundColor = .red
feedCV.showsVerticalScrollIndicator = true
feedCV.isScrollEnabled = true
feedCV.bounces = true
feedCV.delegate = self
feedCV.dataSource = self
// YOUR COLLECTIONVIEW CELL HERE!!!!!
feedCV.register(VideoCollectionViewCell.self, forCellWithReuseIdentifier: VideoCollectionViewCell.ID)
}
// Animate the header view to collapsed or expanded if it is dragged only partially
func animateHeaderViewHeight () -> Void {
Logger.verbose("animateHeaderViewHeight")
var headerViewHeightDestinationConstant : CGFloat = 0.0
if (headerViewHeight < ((expandedHeaderViewHeight - collapsedHeaderViewHeight) / 2.0 + collapsedHeaderViewHeight)) {
headerViewHeightDestinationConstant = collapsedHeaderViewHeight
} else {
headerViewHeightDestinationConstant = expandedHeaderViewHeight
}
if (headerViewHeight != expandedHeaderViewHeight && headerViewHeight != collapsedHeaderViewHeight) {
let animationDuration = 0.25
UIView.animate(withDuration: animationDuration, animations: { () -> Void in
self.headerViewHeight = headerViewHeightDestinationConstant
let progress = (self.headerViewHeight - self.collapsedHeaderViewHeight) / (self.expandedHeaderViewHeight - self.collapsedHeaderViewHeight)
self.headerView.expandToProgress(progress)
self.view.layoutIfNeeded()
})
}
}
}
extension APDynamicHeaderTableViewController : UICollectionViewDelegate {
}
extension APDynamicHeaderTableViewController : UIScrollViewDelegate {
func scrollViewWillBeginDragging(_ scrollView: UIScrollView) {
// Clamp the beginning point to 0 and the max content offset to prevent unintentional resizing when dragging during rubber banding
tableViewScrollOffsetBeginDraggingY = min(max(scrollView.contentOffset.y, 0), scrollView.contentSize.height - scrollView.frame.size.height)
// Keep track of whether or not the header was collapsed to determine if we can add the delay of expansion
headerBeganCollapsed = (headerViewHeight == collapsedHeaderViewHeight)
}
func scrollViewDidScroll(_ scrollView: UIScrollView) {
// Do nothing if the table view is not scrollable
if feedCV.contentSize.height < feedCV.bounds.height {
return
}
var contentOffsetY = feedCV.contentOffset.y - tableViewScrollOffsetBeginDraggingY
// Add a delay to expanding the header only if the user began scrolling below the allotted amount of space to actually expand the header with no delay (e.g. If it takes 30 pixels to scroll up the scrollview to expand the header then don't add the delay of the user started scrolling at 10 pixels)
if tableViewScrollOffsetBeginDraggingY > ((expandedHeaderViewHeight - collapsedHeaderViewHeight) + headerExpandDelay) && contentOffsetY < 0 && headerBeganCollapsed {
contentOffsetY = contentOffsetY + headerExpandDelay
}
// Calculate how much the header height will change so we can readjust the table view's content offset so it doesn't scroll while we change the height of the header
let changeInHeaderViewHeight = headerViewHeight - min(max(headerViewHeight - contentOffsetY, collapsedHeaderViewHeight), expandedHeaderViewHeight)
headerViewHeight = min(max(headerViewHeight - contentOffsetY, collapsedHeaderViewHeight), expandedHeaderViewHeight)
let progress = (headerViewHeight - collapsedHeaderViewHeight) / (expandedHeaderViewHeight - collapsedHeaderViewHeight)
// Logger.verbose("headerViewHeight:",headerViewHeight)
headerView.expandToProgress(progress)
headerView.snp.updateConstraints { (make) -> Void in
make.height.equalTo(headerViewHeight)
}
// When the header view height is changing, freeze the content in the table view
if headerViewHeight != collapsedHeaderViewHeight && headerViewHeight != expandedHeaderViewHeight {
feedCV.contentOffset = CGPoint(x: 0, y: feedCV.contentOffset.y - changeInHeaderViewHeight)
}
}
// Animate the header view when the user ends dragging or flicks the scroll view
func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
animateHeaderViewHeight()
}
func scrollViewDidEndDragging(_ scrollView: UIScrollView, willDecelerate decelerate: Bool) {
animateHeaderViewHeight()
}
}
extension APDynamicHeaderTableViewController : UICollectionViewDataSource {
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 100
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: VideoCollectionViewCell.ID, for: indexPath) as! VideoCollectionViewCell
return cell
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return largeWideSize
}
}
To make hidesBarsOnSwipe working properly, your view controller's view must contain only UITableView instance and nothing else.
The natural direction for a UICollectionView to scroll when set horizontally is from left to right. Is there any way to reverse this? The simpler the better.
I'm not sure exactly what you mean -- if you set the scrolling to horizontal, it scrolls equally well, left and right. If you want it to start it from the right side, you can use this method:
[self.collectionView scrollToItemAtIndexPath:[NSIndexPath indexPathForItem:self.theData.count - 1 inSection:0] atScrollPosition:UICollectionViewScrollPositionRight animated:NO];
This assumes that you have 1 section, and the array populating the collection view is called theData.
Swift4 solution
in cellForItemAt collectionView function
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = categoryBook.dequeueReusableCell(withReuseIdentifier: "HomeCategoryCell", for: indexPath) as! HomeCategoryCell
collectionView.transform = CGAffineTransform(scaleX:-1,y: 1);
cell.transform = CGAffineTransform(scaleX:-1,y: 1);
}
but this solution in some cases did not work properly if it dose not you can use ColletctionView scrollToItem method and you can implement it after you reload the data .
self.YourCollectionView.reloadData()
self.YourCollectionView.scrollToItem(at: NSIndexPath(item: self.YourObjectListData.count - 1, section: 0) as IndexPath, at: .right, animated: false)
Same thing for swift:
collectionView?.scrollToItemAtIndexPath(NSIndexPath(forItem: theData.count - 1, inSection: 0), atScrollPosition: .Right, animated: false)
Use This Extention
extension UICollectionViewFlowLayout {
open override var flipsHorizontallyInOppositeLayoutDirection: Bool {
return true //RETURN true if collection view needs to enable RTL
}
}
I have found using xCode 12.4 with an app that targets iOS 12 that this there seems to be no need to load the items in a different order or do any transforms. The only issue has to do with the initial scroll position. So all I need to do to get things working in both RTL and LTR is the following:
collectionView.reloadData {
if self.collectionView.effectiveUserInterfaceLayoutDirection == .rightToLeft {
self.collectionView?.scrollToItem(at: IndexPath(row:0, section:0), at: .right, animated: false)
}
}
When you create a UITableView with the UITableViewStyleGrouped style, it adds quite a lot of space in between the actual tableviewcells and the borders of the table's frame. This space is above, below, to the left, and to the right of the tableviewcells.
You can change the space between tableviewcells themselves by:
[myTableView setSectionHeaderHeight:0];
[myTableView setSectionFooterHeight:25];
However, even by doing that, there's still this annoying space between the top of the frame and the first tableviewcell. Furthermore, there's a ton of space still in between the left of the frame and the tableviewcell, as well as the right side of the frame and the tableviewcell.
-=-=-=-=-=-=-
Is there a way to manipulate that space (resize it)? My only solution thus far is to make the size of the frame larger than the screen to fake out the program into having that "blank space" outside of the screen, thus removing it. However, this is obviously not optimal and a clear hack.
The space is there because of the UITableView's tableHeaderView property. When the the tableHeaderView property is nil Apple defaults a view. So the way around this is to create an empty view with a height greater than 0. Setting this overrides the default view thereby removing the unwanted space.
This can be done in a Storyboard by dragging a view to the top of a tableView and then setting the height of the view to a value of 1 or greater.
Or it can be done programmatically with the following code:
Objective-C:
CGRect frame = CGRectZero;
frame.size.height = CGFLOAT_MIN;
[self.tableView setTableHeaderView:[[UIView alloc] initWithFrame:frame]];
Swift:
var frame = CGRect.zero
frame.size.height = .leastNormalMagnitude
tableView.tableHeaderView = UIView(frame: frame)
Comments
As others have noted you can use this same solution for footers.
Sources and Acknowledgements
See the Documentation for more details on the tableHeaderView property.
Thanks to #liushuaikobe for verifying using the least positive normal number works.
Answer in Swift 4
If the table view is selected in interface builder and in the attributes inspector the style "Grouped" is selected, enter the following code in your view controller to fix the extra header space issue.
func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
return CGFloat.leastNonzeroMagnitude
}
Use it in the viewDidLoad() method.
tableView.tableHeaderView = UIView(frame: CGRect(x: 0.0, y: 0.0, width: 0.0, height: Double.leastNormalMagnitude))
Single line solution:
Objective-C
self.tableView.tableHeaderView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 0, CGFLOAT_MIN)];
Swift
self.tableView.tableHeaderView = UIView(frame: CGRect(x: 0.0, y: 0.0, width: 0.0, height: Double(FLT_MIN)))
Follow these steps to save your day.
Select grouped attributes from the storyboard.
func tableView(_ tableView: UITableView, heightForFooterInSection section: Int) -> CGFloat {
return CGFloat.leastNonzeroMagnitude
}
func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
return CGFloat.leastNonzeroMagnitude
}
If you are using ios 15 do this also —
if #available(iOS 15.0, *){
self.tableViewSavedRecent.sectionHeaderTopPadding = 0.0
}
For iOS 11.0+
tableView.contentInsetAdjustmentBehavior = .never
If the style of your tableView is UITableViewStyleGrouped, then you have to pay attention to the delegate of the height of SectionHeader or SectionFooter, cause this needs to be implemented right under this case.
The return value should not be 0, even if the SectionHeader or the height of SectionFooter is 0, it needs to be a very small value; try CGFLOAT_MIN.
For my example:
- (CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section{
if (section == [self.dataArray indexOfObject:self.bannerList]) {
return 46;
}
return CGFLOAT_MIN;
}
- (CGFloat)tableView:(UITableView *)tableView heightForFooterInSection:(NSInteger)section {
return CGFLOAT_MIN;
}
Make sure you implemented these two methods, and the value is right, and the top margin will be fixed.
You need to set footer too
-(CGFloat)tableView:(UITableView *)tableView heightForFooterInSection:(NSInteger)section{
return 0;
}
-(UIView *)tableView:(UITableView *)tableView viewForFooterInSection:(NSInteger)section{
return [[UIView alloc] initWithFrame:CGRectZero];
}
func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
return CGFloat.leastNonzeroMagnitude
}
Below location icon is table with top spacing zero.
I had to combine both delegate functions for it to work:
func tableView(_ tableView: UITableView, heightForFooterInSection section: Int) -> CGFloat {
return .leastNonzeroMagnitude
}
func tableView(_ tableView: UITableView, viewForFooterInSection section: Int) -> UIView? {
return UIView(frame: CGRect(x: 0.0, y: 0.0, width: 0.0, height: .leastNonzeroMagnitude))
}
None of above solution worked for me
In my case these setting was set to manual i just changed to Automatic
If you are using a TableHeaderView with an insetGroup styled UITableView you can do the following:
class CustomTableHeaderView: UIView {
init() {
super.init(frame: CGRect(x: 0, y: 0, width: 0, height: CGFloat.leastNormalMagnitude))
--- do your header view setup here. ---
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
How can I modify the height of a header section accordantly to the view I'm adding it?
heightForHeaderInSection is called before viewForHeaderInSection and I don't know the view size until I create it.
You can follow this:
Create a property for headerView (NSArray if multiple header views).
Create the view in "heightForHeaderInSection" itself.
Assign your view to property.
return the height of your view in "heightForHeaderInSection".
In "viewForHeaderInSection" return this property.
Yeah, it seems strange/redundant that you have to create both the view and then also determine the size of that view as a completely separate event, but you can minimize the silliness by moving some of that shared logic into some shared method. E.g., you probably have to figure out the size of the view at some point during it's creation, so move that logic to some shared method.
For example, I have logic that I use for determining the size of the UILabel I'm putting in my header based upon the size of the text. So I pulled that out of my viewForHeaderInSection and moved it into my own method, sizeForHeaderLabelInSection, which I use to determine the size of my label control):
- (CGSize)tableView:(UITableView *)tableView sizeForHeaderLabelInSection:(NSInteger)section
{
NSString *text = [self tableView:tableView titleForHeaderInSection:section];
CGSize constraint = CGSizeMake(self.view.frame.size.width - kSectionTitleLeftMargin - kSectionTitleRightMargin, kMaxSectionTitleHeight);
return [text sizeWithFont:[self fontForSectionHeader] constrainedToSize:constraint lineBreakMode:UILineBreakModeWordWrap];
}
Then, I modified the standard heightForHeaderInSection to use that method, adding, of course, my top and bottom margin around my UILabel:
- (CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section
{
return [self tableView:tableView sizeForHeaderLabelInSection:section].height + kSectionTitleTopMargin + kSectionTitleBottomMargin;
}
And then I modified the standard viewForHeaderInSection to also use this sizeForHeaderLabelInSection, too:
- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section
{
CGSize size = [self tableView:tableView sizeForHeaderLabelInSection:section];
UIView* headerView = [[UIView alloc] initWithFrame:CGRectMake(0.0, 0.0, size.width + kSectionTitleLeftMargin + kSectionTitleRightMargin, size.height + kSectionTitleTopMargin + kSectionTitleBottomMargin)];
//headerView.contentMode = UIViewContentModeScaleToFill;
// Add the label
UILabel *headerLabel = [[UILabel alloc] initWithFrame:CGRectMake(kSectionTitleLeftMargin,
kSectionTitleTopMargin,
size.width,
size.height)];
// put stuff to set up my headerLabel here...
[headerView addSubview:headerLabel];
// Return the headerView
return headerView;
}
Clearly, how you do this is completely up to you and what you're trying to achieve. But I think you'll have success if you shift your mindset from "how do I figure out the size of that view I created in viewForHeaderInSection" to "how can I move the the code that I used for determining the size in viewForHeaderInSection into some common method that my heightForSectionInHeader can use, too.
This also works:
Override estimatedHeightForHeaderInSection, return a CGFloat, whatever, but not 0.
Create a CGFloat property to save the height for header view.
var sectionHeaderViewHeight:CGFloat = 10.0
(The value is not important, but never set to 0.0, if you do this, viewForHeaderInSection will never be invoked, you will never have a section header view!)
Override heightForHeaderInSection and return that property.
override func tableView(tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
return sectionHeaderViewHeight
}
Create the header view in viewForHeaderInSection
override func tableView(tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
let headerView = UIView()
//configuration your view
//.....
return headerView
}
This is the key step: Add these code before return headerView.
self.tableView.beginUpdates()
sectionHeaderViewHeight = //The value you would like to set
self.tableView.endUpdates()
It looks like this:
override func tableView(tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
let headerView = UIView()
//configuration your view
//.....
//----Key Steps:----
self.tableView.beginUpdates()
sectionHeaderViewHeight = //The value you would like to set
self.tableView.endUpdates()
//----Key Steps----
return headerView
}
var sectionHeaderViewHeight:CGFloat = 10.0
override func tableView(tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
return sectionHeaderViewHeight
}
To force calling heightForHeaderInSection method, you just need to call both methods beginUpdates/endUpdates of the UITableView.
First create and init a variable height and return it
var height: CGFloat = 160.0
func tableView(tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
return height
}
Then add a method that will update the section height with a new value
func updateHeaderHeight(newHeight: CGFloat) {
tableView.beginUpdates()
height = newHeight
tableView.endUpdates()
}