There is table view in scroll view, for the perfect scrolling need height of table view. But there is dynamic height of cell and in cell multiple content with dynamic data like image(calculating height of image with kingfisher library) and content(with 0 number of lines). So unable to calculate height of each cell. So I am using this for getting height of cell:-
let totalCount = self.itemArray.data1.count + self.itemArray.data2.count
if totalCount != self.totalHeightOfTable.count {
//Appending height of cell
self.tableView.reloadData()
self.totalHeightOfTable.append(cell.frame.height)
self.heightOfPost = self.totalHeightOfTable
if totalCount == self.totalHeightOfTable.count {
// Call back to get height of tableView
self.getTotalHeightOfTableView?(self.totalHeightOfTable)
}
}
because the tableView is inside a scrollview , I am not able to calculate the height for each cell of the tableView dynamically or at run time. The height I get at runtime is greater and there is a blank white space at the end of the tableView. So the total height for table view is always greater than the sum of all the cells in the table view.
UI structure attached
I understood your problem that you want to calculate dynamic table height with flexible cells height inside tableview and according to this height you want to update your parent scrollview contentSize height .
I want to tell you that please remove your all your height calculation and just place this below simple function in side your view controller.
IMPORTANT:- Don't give any Height Constraint to your table view if you are using AutoLayout from your storyboard or programatically.
kindly take care of your variable names of tableview and scrollview and replace them respectively .
//MARK:- viewDidLayoutSubviews will call after dynamic height calculation automatically
override func viewDidLayoutSubviews() {
//isScrollEnabled of table view should be dissable because our table is inside scrollview.
tableView.isScrollEnabled = false
//if above tableView.contentSize.height not zero and giving acurate value then proceed further and update our parent scroll view contentsize height for height.
print(tableView.contentSize.height)
//place some bottom peeding as you want
let bottomPedding:CGFloat = 30
//Finally update your scrollview content size with newly created table height + bottom pedding.
scrollview.contentSize = CGSize.init(width: scrollview.contentSize.width, height:tableView.contentSize.height + bottomPedding)
}
if this will work then fantastic then great , rest you can contact me any time we will figure it out.
asrathoreforiphone#gmail.com
You can use the height of the contentSize by taleView.contentSize.height
Welcome to Stackoverflow!
You can definitely get the contentSize, and get the height from that, of your tableView. I've been using this method and works every time.
One way to do it is to add an observer, like so:
tableView.addObserver(self, forKeyPath: "contentSize", options: .new, context: nil)
and then override your controller's method, observeValue, like so:
override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
if let obj = object as? UITableView {
if obj == self.tableView && keyPath == "contentSize" {
if let newSize = change?[NSKeyValueChangeKey.newKey] as? CGSize {
let height = newSize.height // <----- your height!
}
}
}
}
To add, perhaps it would be best if in your viewWillDisappear or deinit method, remove that observer.
I've set up a UITableViewCell with UITableViewAutomaticDimension
The TableViewCell has a UICollectionView embedded in it which is not scrollable but can have a variable height based on the content of the collectionview.
Right now what I've tried is the render the cell and assign the height constraint of the collectionview to a variable collectionViewHeightConstraint and then update the height once the collectionview is rendered in the layoutSubviews method
override func layoutSubviews() {
super.layoutSubviews()
self.collectionViewHeightConstraint?.constant = self.collectionView!.contentSize.height
}
This is what the collectionview constraints look like (using cartography) :
self.contentView.addSubview(self.collectionview)
self.contentView.addSubview(self.holdingView)
constrain(self.holdingView!, self.contentView) {
holderView, container in
holderView.top == container.top
holderView.left == container.left
holderView.right == container.right
holderView.bottom == container.bottom
}
constrain(self.collectionView!, self.holdingView) {
collectionView, containerView in
collectionView.top == containerView.top
collectionView.left == containerView.left
collectionView.right == containerView.right
collectionViewHeightConstraint = collectionView.height == collectionViewHeight
containerView.bottom == collectionView.bottom
}
But that does not seem to update the cell height.
Is there any way to update the same?
Edit
This is not a duplicate question as suggested by some people and the explanation of why is in the comments below.
Since the comment was too small a space, I'll put everything here:
Note: You don't actually have to set the height constraint in viewDidLayoutSubviews just somewhere you can be sure that the UICollectionView has been set and your layout has been setup properly on your whole screen! For example, doing it in viewDidAppear and then calling layoutIfNeeded() will also work. Moving it into viewDidAppear will only work if you have your UICollectionView setup before viewDidAppear is called i.e you know your UICollectionView dataSource beforehand.
Fix 1:
Try reloading the UITableView after setting the height and checking if the heightConstant != contentSize. Use this to check if the height of the UICollectionView is updated properly i.e.:
override func layoutSubviews() {
super.layoutSubviews()
if self.collectionViewHeightConstraint?.constant != self.collectionView!.contentSize.height{
self.collectionViewHeightConstraint?.constant = self.collectionView!.contentSize.height
//to make sure height is recalculated
tableView.reloadData()
//or reload just the row depending on use case and if you know the index of the row to reload :)
}
}
I agree with your comment and that it is messy, I meant use that as a fix and/or to check if that is where the problem lies actually!
As for why it is 0, that happens probably because your UICollectionView hasn't been set yet (cellForItem hasn't been called yet) so contentSize isn't actually calculated!
Fix 2:
Once your dataSource for the UICollectionView has been set, that is you receive the data, you calculate the height the UICollectionView contentSize will have manually and set it once and reload the row. If the calculation is a tedious task, just set the dataSource and call reloadData on UICollectionView. This will ensure the UICollectionView is setup properly and then set the constraint of the cell to be the contentSize and call reloadData or reloadRow on the UITableView.
You basically can set the heightConstraint anytime after your UICollectionView has been setup and your view has been laid out. You just need to called tableView.reloadData() afterwards.
You can reload particular cell of tableview
let indexPath = IndexPath(item: rowNumber, section: 0)
tableView.reloadRows(at: [indexPath], with: .top)
Going by your requirement, I guess if we load the collectionview first and then load the tableview with the correct height of the collectionview, we can solve this.
collectionView.reloadData()
dispatch_async(dispatch_get_main_queue(), { () -> Void in
self.collectionViewHeightConstraint?.constant = self.collectionView!.contentSize.height
})
tableview.reloadData()
By this when tableview loads the cell has the desired height based on the collection view content size.
I have a UITableViewController embedded in a UIView container, which is at the bottom of a UIScrollView in a UIViewController. Here is a screenshot of the current configuration in the storyboard.
The UITableView will contain responses to the selected post. Because the height and number of responses in the UITableView will be variable, I want the UIView container's height to change based on the height of the table. The current (undesirable) behavior is the UIView container stays a constant height, and scrolls when the UITableView height is greater than the UIView containter's height.
The most viable method seems to be having the UITableViewController pass the height of the table to the UIViewController using prepareForSegue, and then set the UIView's height to that passed value. However, I can't seem to set a value with the height of the table until after prepareForSegue is run.
What Isn't Working
Set the identifier of the embed segue between the UIView and the UITableViewController to "embedSegue"
At the top of the the embedded UITableViewController class, create a variable to hold the height of the table:
var tableHeight: CGFloat!
Still in the embedded UITableViewController, override viewDidLoad like so, printing passedHeight to the console for checking:
override func viewDidLoad() {
super.viewDidLoad()
self.tableView.estimatedRowHeight = 68.0
self.tableView.rowHeight = UITableViewAutomaticDimension
self.tableHeight = self.tableView.contentSize.height
print(tableHeight)
}
In the UIViewController class that contains the UIView container, create a variable to hold the value passed from the UITableViewController:
var viewHeight: CGFloat!
Still in the UIViewController, override prepareForSegue like so, setting viewHeight to the passed tableHeight value, and printing viewHeight to the console for checking:
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "embedSegue" {
let responseTableView = segue.destinationViewController as! ResponseViewController
self.viewHeight = responseTableView.tableHeight
if viewHeight == nil {
print("Nil")
} else {
print(viewHeight)
}
}
}
When I run the app, viewHeight prints as Nil first, then tableHeight prints, which means prepareForSegue has run prior to tableHeight being set.
I have also tried other methods besides prepareForSegue, including calling various functions on the UIView container in viewDidLayoutSubviews() like:
.sizeThatFits()
.needsUpdateConstraints()
.layoutIfNeeded()
However, the UIView container remains the same height as set in the storyboard.
As an epilogue, this is my first StackOverflow post, and I'm excited to be joining the community. Please do let me know if I can clarify my question. Thank you for taking the time.
Instead of using a UIViewController with a UIScrollView containing three UIViews, I created one UITableView with three custom cells. Each cell has their own custom UITableViewCell class for flexibility.
This meant I lost the ability to use constraints to dynamically change the height of each section. I wanted the Post Title and Post Text to be centered on a fullscreen image. To achieve this, I added the logic below:
override func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
if indexPath.row == 0 {
//Fullscreen image cell - the "20" is for the status bar
return tableView.frame.size.height - self.navigationController!.navigationBar.frame.size.height - 20
} else {
//Just use the current rowHeight
return self.tableView.rowHeight
}
}
References
How to embed a UITableView in a UIScrollview
A short answer to a similar question which sparked the idea
UITableview with more than One Custom Cells with Swift
Detailed explanation of how to create a UITableView with 3 custom UITableViewCells
One of our application screens requires us to place a UICollectionView inside of a UITableViewCell. This UICollectionView will have a dynamic number of items, resulting in a height which must be calculated dynamically as well. However, I am running into problems trying to calculate the height of the embedded UICollectionView.
Our overarching UIViewController was created in Storyboards and does make use of auto layout. But, I don't know how to dynamically increase the height of the UITableViewCell based on the height of the UICollectionView.
Can anyone give some tips or advice on how to accomplish this?
The right answer is YES, you CAN do this.
I came across this problem some weeks ago. It is actually easier than you may think. Put your cells into NIBs (or storyboards) and pin them to let auto layout do all the work
Given the following structure:
TableView
TableViewCell
CollectionView
CollectionViewCell
CollectionViewCell
CollectionViewCell
[...variable number of cells or different cell sizes]
The solution is to tell auto layout to compute first the collectionViewCell sizes, then the collection view contentSize, and use it as the size of your cell. This is the UIView method that "does the magic":
-(void)systemLayoutSizeFittingSize:(CGSize)targetSize
withHorizontalFittingPriority:(UILayoutPriority)horizontalFittingPriority
verticalFittingPriority:(UILayoutPriority)verticalFittingPriority
You have to set here the size of the TableViewCell, which in your case is the CollectionView's contentSize.
CollectionViewCell
At the CollectionViewCell you have to tell the cell to layout each time you change the model (e.g.: you set a UILabel with a text, then the cell has to be layout again).
- (void)bindWithModel:(id)model {
// Do whatever you may need to bind with your data and
// tell the collection view cell's contentView to resize
[self.contentView setNeedsLayout];
}
// Other stuff here...
TableViewCell
The TableViewCell does the magic. It has an outlet to your collectionView, enables the auto layout for collectionView cells using estimatedItemSize of the UICollectionViewFlowLayout.
Then, the trick is to set your tableView cell's size at the systemLayoutSizeFittingSize... method. (NOTE: iOS8 or later)
NOTE: I tried to use the delegate cell's height method of the tableView -(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath.but it's too late for the auto layout system to compute the CollectionView contentSize and sometimes you may find wrong resized cells.
#implementation TableCell
- (void)awakeFromNib {
[super awakeFromNib];
UICollectionViewFlowLayout *flow = (UICollectionViewFlowLayout *)self.collectionView.collectionViewLayout;
// Configure the collectionView
flow.minimumInteritemSpacing = ...;
// This enables the magic of auto layout.
// Setting estimatedItemSize different to CGSizeZero
// on flow Layout enables auto layout for collectionView cells.
// https://developer.apple.com/videos/play/wwdc2014-226/
flow.estimatedItemSize = CGSizeMake(1, 1);
// Disable the scroll on your collection view
// to avoid running into multiple scroll issues.
[self.collectionView setScrollEnabled:NO];
}
- (void)bindWithModel:(id)model {
// Do your stuff here to configure the tableViewCell
// Tell the cell to redraw its contentView
[self.contentView layoutIfNeeded];
}
// THIS IS THE MOST IMPORTANT METHOD
//
// This method tells the auto layout
// You cannot calculate the collectionView content size in any other place,
// because you run into race condition issues.
// NOTE: Works for iOS 8 or later
- (CGSize)systemLayoutSizeFittingSize:(CGSize)targetSize withHorizontalFittingPriority:(UILayoutPriority)horizontalFittingPriority verticalFittingPriority:(UILayoutPriority)verticalFittingPriority {
// With autolayout enabled on collection view's cells we need to force a collection view relayout with the shown size (width)
self.collectionView.frame = CGRectMake(0, 0, targetSize.width, MAXFLOAT);
[self.collectionView layoutIfNeeded];
// If the cell's size has to be exactly the content
// Size of the collection View, just return the
// collectionViewLayout's collectionViewContentSize.
return [self.collectionView.collectionViewLayout collectionViewContentSize];
}
// Other stuff here...
#end
TableViewController
Remember to enable the auto layout system for the tableView cells at your TableViewController:
- (void)viewDidLoad {
[super viewDidLoad];
// Enable automatic row auto layout calculations
self.tableView.rowHeight = UITableViewAutomaticDimension;
// Set the estimatedRowHeight to a non-0 value to enable auto layout.
self.tableView.estimatedRowHeight = 10;
}
CREDIT: #rbarbera helped to sort this out
I think my solution is much simpler than the one proposed by #PabloRomeu.
Step 1. Create outlet from UICollectionView to UITableViewCell subclass, where UICollectionView is placed. Let, it's name will be collectionView
Step 2. Add in IB for UICollectionView height constraint and create outlet to UITableViewCell subclass too. Let, it's name will be collectionViewHeight.
Step 3. In tableView:cellForRowAtIndexPath: add code:
// deque a cell
cell.frame = tableView.bounds;
[cell layoutIfNeeded];
[cell.collectionView reloadData];
cell.collectionViewHeight.constant = cell.collectionView.collectionViewLayout.collectionViewContentSize.height;
Both table views and collection views are UIScrollView subclasses and thus don't like to be embedded inside another scroll view as they try to calculate content sizes, reuse cells, etc.
I recommend you to use only a collection view for all your purposes.
You can divide it in sections and "treat" some sections' layout as a table view and others as a collection view. After all there's nothing you can't achieve with a collection view that you can with a table view.
If you have a basic grid layout for your collection view "parts" you can also use regular table cells to handle them. Still if you don't need iOS 5 support you should better use collection views.
I read through all the answers. This seems to serve all cases.
override func systemLayoutSizeFitting(_ targetSize: CGSize, withHorizontalFittingPriority horizontalFittingPriority: UILayoutPriority, verticalFittingPriority: UILayoutPriority) -> CGSize {
collectionView.layoutIfNeeded()
collectionView.frame = CGRect(x: 0, y: 0, width: targetSize.width , height: 1)
return collectionView.collectionViewLayout.collectionViewContentSize
}
Pablo Romeu's answer above (https://stackoverflow.com/a/33364092/2704206) helped me immensely with my issue. I had to do a few things differently, however, to get this working for my problem. First off, I didn't have to call layoutIfNeeded() as often. I only had to call it on the collectionView in the systemLayoutSizeFitting function.
Secondly, I had auto layout constraints on my collection view in the table view cell to give it some padding. So I had to subtract the leading and trailing margins from the targetSize.width when setting the collectionView.frame's width. I also had to add the top and bottom margins to the return value CGSize height.
To get these constraint constants, I had the option of either creating outlets to the constraints, hard-coding their constants, or looking them up by an identifier. I decided to go with the third option to make my custom table view cell class easily reusable. In the end, this was everything I needed to get it working:
class CollectionTableViewCell: UITableViewCell {
// MARK: -
// MARK: Properties
#IBOutlet weak var collectionView: UICollectionView! {
didSet {
collectionViewLayout?.estimatedItemSize = CGSize(width: 1, height: 1)
selectionStyle = .none
}
}
var collectionViewLayout: UICollectionViewFlowLayout? {
return collectionView.collectionViewLayout as? UICollectionViewFlowLayout
}
// MARK: -
// MARK: UIView functions
override func systemLayoutSizeFitting(_ targetSize: CGSize, withHorizontalFittingPriority horizontalFittingPriority: UILayoutPriority, verticalFittingPriority: UILayoutPriority) -> CGSize {
collectionView.layoutIfNeeded()
let topConstraintConstant = contentView.constraint(byIdentifier: "topAnchor")?.constant ?? 0
let bottomConstraintConstant = contentView.constraint(byIdentifier: "bottomAnchor")?.constant ?? 0
let trailingConstraintConstant = contentView.constraint(byIdentifier: "trailingAnchor")?.constant ?? 0
let leadingConstraintConstant = contentView.constraint(byIdentifier: "leadingAnchor")?.constant ?? 0
collectionView.frame = CGRect(x: 0, y: 0, width: targetSize.width - trailingConstraintConstant - leadingConstraintConstant, height: 1)
let size = collectionView.collectionViewLayout.collectionViewContentSize
let newSize = CGSize(width: size.width, height: size.height + topConstraintConstant + bottomConstraintConstant)
return newSize
}
}
As a helper function to retrieve a constraint by identifier, I add the following extension:
extension UIView {
func constraint(byIdentifier identifier: String) -> NSLayoutConstraint? {
return constraints.first(where: { $0.identifier == identifier })
}
}
NOTE: You will need to set the identifier on these constraints in your storyboard, or wherever they are being created. Unless they have a 0 constant, then it doesn't matter. Also, as in Pablo's response, you will need to use UICollectionViewFlowLayout as the layout for your collection view. Finally, make sure you link the collectionView IBOutlet to your storyboard.
With the custom table view cell above, I can now subclass it in any other table view cell that needs a collection view and have it implement the UICollectionViewDelegateFlowLayout and UICollectionViewDataSource protocols. Hope this is helpful to someone else!
An alternative to Pablo Romeu's solution is to customise UICollectionView itself, rather than doing the work in table view cell.
The underlying problem is that by default a collection view has no intrinsic size and so cannot inform auto layout of the dimensions to use. You can remedy that by creating a custom subclass which does return a useful intrinsic size.
Create a subclass of UICollectionView and override the following methods
override func intrinsicContentSize() -> CGSize {
self.layoutIfNeeded()
var size = super.contentSize
if size.width == 0 || size.height == 0 {
// return a default size
size = CGSize(width: 600, height:44)
}
return size
}
override func reloadData() {
super.reloadData()
self.layoutIfNeeded()
self.invalidateIntrinsicContentSize()
}
(You should also override the related methods: reloadSections, reloadItemsAtIndexPaths in a similar way to reloadData())
Calling layoutIfNeeded forces the collection view to recalculate the content size which can then be used as the new intrinsic size.
Also, you need to explicitly handle changes to the view size (e.g. on device rotation) in the table view controller
override func viewWillTransitionToSize(size: CGSize, withTransitionCoordinator coordinator: UIViewControllerTransitionCoordinator)
{
super.viewWillTransitionToSize(size, withTransitionCoordinator: coordinator)
dispatch_async(dispatch_get_main_queue()) {
self.tableView.reloadData()
}
}
Easiest approach I've came up with, so far, Credits to #igor answer above,
In your tableviewcell class just insert this
override func layoutSubviews() {
self.collectionViewOutlet.constant = self.postPoll.collectionViewLayout.collectionViewContentSize.height
}
and of course, change the collectionviewoutlet with your outlet in the cell's class
I was facing the same issue recently and I almost tried every solution in the answers, some of them worked and others didn't my main concern about #PabloRomeu approach is that if you have other contents in the cell (other than the collection view) you will have to calculate their heights and the heights of their constraints and return the result to get the auto layout right and I don't like to calculate things manually in my code. So here is the solution that worked fine for me without doing any manual calculations in my code.
in the cellForRow:atIndexPath of the table view I do the following:
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
//do dequeue stuff
//initialize the the collection view data source with the data
cell.frame = CGRect.zero
cell.layoutIfNeeded()
return cell
}
I think what happens here is that I force the tableview cell to adjust its height after the collection view height has been calculated. (after providing the collectionView date to the data source)
I would put a static method on the collection view class that will return a size based on the content it will have. Then use that method in the heightForRowAtIndexPath to return the proper size.
Also note that you can get some weird behavior when you embed these kinds of viewControllers. I did it once and had some weird memory issues I never worked out.
Maybe my variant will be useful; i've been deciding this task during last two hours. I don't pretend it's 100% correct or optimal, but my skill's very small yet and i'd like to hear comments from experts. Thank you.
One important note: this works for static table - it's specified by my current work.
So, all I use is viewWillLayoutSubviews of tableView. And a little bit more.
private var iconsCellHeight: CGFloat = 500
func updateTable(table: UITableView, withDuration duration: NSTimeInterval) {
UIView.animateWithDuration(duration, animations: { () -> Void in
table.beginUpdates()
table.endUpdates()
})
}
override func viewWillLayoutSubviews() {
if let iconsCell = tableView.cellForRowAtIndexPath(NSIndexPath(forRow: 0, inSection: 1)) as? CategoryCardIconsCell {
let collectionViewContentHeight = iconsCell.iconsCollectionView.contentSize.height
if collectionViewContentHeight + 17 != iconsCellHeight {
iconsCellHeight = collectionViewContentHeight + 17
updateTable(tableView, withDuration: 0.2)
}
}
}
override func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
switch (indexPath.section, indexPath.row) {
case ...
case (1,0):
return iconsCellHeight
default:
return tableView.rowHeight
}
}
I know, that the collectionView is located in the first row of the second section;
Let the height of the row is 17 p. bigger, than its content height;
iconsCellHeight is a random number as the program starts (i know, that in the portrait form it has to be exactly 392, but it's not important). If the content of collectionView + 17 is not equal this number, so change its value. Next time in this situation the condition gives FALSE;
After all update the tableView. In my case its the combination of two operations (for nice updating of extending rows);
And of course, in the heightForRowAtIndexPath add one row to code.
I get idea from #Igor post and invest my time to this for my project with swift
Just past this in your
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
//do dequeue stuff
cell.frame = tableView.bounds
cell.layoutIfNeeded()
cell.collectionView.reloadData()
cell.collectionView.heightAnchor.constraint(equalToConstant: cell.collectionView.collectionViewLayout.collectionViewContentSize.height)
cell.layoutIfNeeded()
return cell
}
Addition:
If you see your UICollectionView choppy when loading cells.
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
//do dequeue stuff
cell.layer.shouldRasterize = true
cell.layer.rasterizationScale = UIScreen.main.scale
return cell
}
Pablo's solution did not work very well for me, I had strange visual effects (the collectionView not adjusting correctly).
What worked was to adjust the height constraint of the collectionView (as a NSLayoutConstraint) to the collectionView contentSize during layoutSubviews(). This is the method called when autolayout is applied to the cell.
// Constraint on the collectionView height in the storyboard. Priority set to 999.
#IBOutlet weak var collectionViewHeightConstraint: NSLayoutConstraint!
// Method called by autolayout to layout the subviews (including the collectionView).
// This is triggered with 'layoutIfNeeded()', or by the viewController
// (happens between 'viewWillLayoutSubviews()' and 'viewDidLayoutSubviews()'.
override func layoutSubviews() {
collectionViewHeightConstraint.constant = collectionView.contentSize.height
super.layoutSubviews()
}
// Call `layoutIfNeeded()` when you update your UI from the model to trigger 'layoutSubviews()'
private func updateUI() {
layoutIfNeeded()
}
func configure(data: [Strings]) {
names = data
contentView.layoutIfNeeded()
collectionviewNames.reloadData()
}
Short and sweet. Consider the above method in your tableViewCell class. You would probably call it from func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell after dequeing your cell. Before calling reloadData on your collection view, in your tableCell, you need to tell the collection view to lay out its subviews, if layout updates are pending.
In your UITableViewDelegate:
-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
return ceil(itemCount/4.0f)*collectionViewCellHeight;
}
Substitute itemCount and CollectionViewCellHeight with the real values. If you have an array of arrays itemCount might be:
self.items[indexPath.row].count
Or whatever.
1.Create dummy cell.
2.Use collectionViewContentSize method on UICollectionViewLayout of UICollectionView using current data.
You can calculate the height of the collection based on its properties like itemSize, sectionInset, minimumLineSpacing, minimumInteritemSpacing, if your collectionViewCell has the border of a rule.
I have embedded a collection view in another view and disabled the collection view's scrolling ability, what i want to achieve is similar to Instagram's profile tab. However, I cannot figure out how should I set the height of the collection view in this case since the number of cells are dynamic.
I tried searching different solutions but most results are on changing the cells dynamically but not the collection view height itself. Is there any default/standard solutions for that?
Set the width you want the collection view to have (hopefully that is static), and request a layout:
collectionView.frame = CGRectMake(0., 0., width, 0.);
[collectionView layoutIfNeeded];
The calculated height of the collectionView will then be available at:
collectionView.contentSize.height
For Swift please follow below steps:
Declare a CGFloat variable in declaration section:
var height : CGFloat!
At viewDidAppear you can get it by:
height = self.myCollectionView.collectionViewLayout.collectionViewContentSize().height
Maybe when you reload data then need to calculate a new height with new data then you can get it by: addObserver to listen when your CollectionView finished reload data at viewWillAppear:
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(true)
....
....
self.shapeCollectionView.addObserver(self, forKeyPath: "contentSize", options: NSKeyValueObservingOptions.Old, context: nil)
}
Then add bellow function to get new height or do anything after collectionview finished reload:
override func observeValueForKeyPath(keyPath: String?, ofObject object: AnyObject?, change: [String : AnyObject]?, context: UnsafeMutablePointer<Void>) {
let newHeight : CGFloat = self.myCollectionView.collectionViewLayout.collectionViewContentSize().height
var frame : CGRect! = self.myCollectionView.frame
frame.size.height = newHeight
self.myCollectionView.frame = frame
}
And don't forget to remove observer:
self.myCollectionView.removeObserver(self, forKeyPath: "contentSize")
I hope this will help you to solve your issue in swift.
1) you need to set height constraint to collectionview in storyboard or xibs
2) make outlet of heightConstraint
3) and use this code while relaod collectionview
collectionViewHeightConstaint.constant = collectionView.contentSize.height
In your ViewController, set the frame of the collectionView. For example:
self.collectionView.frame = CGRectMake(0, 0, 100, 200);
Based on the fact you know the height of the cells and you know the number of cells on the screen. I would...
self.collectionView.frame = CGRectMake(0, 0, DEFINED_WIDTH, DEFINED_CELL_HEIGHT*Number of Cells);
or have I miss understood the question?