Get number of column in a CollectionView IOS - ios

I use an UICollectionView in my first app. My problem is I can't get the number of column (or line) calculated in the UICollectionView.
The UICollectionView is inside an UIScrollView, and I want to set the height of the UICollectionView because I don't want to scroll in the UICollectionView but I want to see all the items.
Is this possible?
Thanks,
F.G

After many researches I found the solution:
I don't need to know the number of column or line in the collection view if I want to fix the height.
The height of the collection view can be updated automatically:
Add a height constrain to the collection view
Add the CollectionView and the constrain as outlets in the ViewController:
#IBOutlet weak var heightConstrainCollectionView: NSLayoutConstraint!
#IBOutlet weak var myCollectionView: UICollectionView!
After the view Load, update the height of the CollectionView:
override func viewDidAppear(animated: Bool) {
super.viewDidLoad()
heightConstrainCollectionView.constant = myCollectionView.contentSize.height
}
If the user rotate the device, update the CollectionView's height:
override func didRotateFromInterfaceOrientation(fromInterfaceOrientation: UIInterfaceOrientation) {
heightConstrainCollectionView.constant = myCollectionView.contentSize.height
// Add this if you want to see the height after rotation
println("New Width: \(newspaperCollectionView.contentSize.height)")
}
Now I can't scroll in my CollectionView and the CollectionView show all the items

Related

How to increase and decrease UIView height by codebase using Swift

In my case, I have to add UIView in top of the Tableview but it should be inside Tableview because of scrolling. Here, I drag and dropped UIView on topside tableview. Now, some scenario I need to increase and reduce height of the UIView. I tried to add constraints but its not available. How to achieve this by codebase?
Tableview with UIView Storyboard Hierarchy
Storyboard Design
Disabled Constraints For UIView
Constraints is not working with table header view. you can set table header using custom view and update its frame
Set a custom view
Set table header and update it's frame
class ViewController: UIViewController {
#IBOutlet var tableView: UITableView!
#IBOutlet var tableHeader: UIView!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
loadHeader()
}
func loadHeader() {
tableHeader.frame = CGRect(x: 0, y: 0, width: self.view.frame.size.width, height: 300)
tableView.tableHeaderView = tableHeader
}
}

ScrollView does not scroll in iOS

I want to allow users to scroll left or right but only one screen far.
//
// MainViewController.swift
// Calendar
//
// Created by Andy on 7/22/17.
// Copyright © 2017 Andy. All rights reserved.
//
import UIKit
class MainViewController: UIViewController, UIScrollViewDelegate {
#IBOutlet weak var ScrollView: UIScrollView!{
didSet{
ScrollView.delegate = self
ScrollView.contentSize = CGSize(width: ScrollView.frame.width * 3, height: ScrollView.frame.height)
}
}
#IBOutlet weak var center: UIView!
#IBOutlet weak var left: UIView!
#IBOutlet weak var right: UIView!
override func viewDidLoad() {
super.viewDidLoad()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if let destination = segue.destination as? ReusableViewController {
if let identifier = segue.identifier{
destination.currentYearOffSet = 0
destination.currentMonthOffSet = 0
switch identifier {
case "center":
destination.position = .center
case "left":
destination.position = .left
case "right":
destination.position = .right
default:
fatalError("Unexpected Segue Identifier")
}
}
}
}
}
This Controller does nothing more than getting the scroll work. And inside the scrollview there are three containerViews managed by other controllers. But that simply does not work.
I have done the following to solve the problem but in vain: 1. Check the content size of scrollView. 2. Hook up the controller and the three containerViews. 3. Set the scrollView delegate but I haven't implemented any method.(Maybe that's the cause but I don't know what to implement)
Plus, do I need to hook up those three containerViews when the controller does nothing about them?
EDIT: I removed: 1. contentSize 2. UIScrollViewDelegate 3. outlets of the three containerViews. This does make my code a lot more nicer, but scrollView still cannot scroll.
EDIT2: I add a view which is exactly the size I want scrollView.contentSize to be as the scrollView's immediate subview. And it seem that the content height is solved because it's only saying that the content width is ambiguous. It want to to add leading and trailing constraints to the view I added but I want it to just center horizontally in the scrollView. Now I need to set the leading and trailing constraints to let autoLayout know the contentWidth. How can I set the leading and trailing offSet based on the width of its superview or I'm supposed to do something else to solve this problem?
You do not need to set like this:-
#IBOutlet weak var ScrollView: UIScrollView!{
didSet{
ScrollView.delegate = self
ScrollView.contentSize = CGSize(width: ScrollView.frame.width * 3, height: ScrollView.frame.height)
}
}
Just having outlet #IBOutlet weak var ScrollView: UIScrollView! and pinning proper constraint(leading, trailing, top, bottom, equal Width(should be equal to or greater than to), equal height (should be equal to or greater than to).
For Horizontal scroll
If you wanted to scrolling horizontally then also pinned width constraint, this is required to avoid auto layout error but inside placeholder checked Remove at build time.
For Vertical scroll
If you wanted to scrolling vertically then also pinned height constraint, this is required to avoid auto layout error
but inside placeholder checked Remove at build time.
Note:- You can use either both or any one based on your requirement.

Scrollview just show my last array's element in view which i create with storyboard in swift 3?

I want to add a few view in scrollview. But I dont want to this view programmatically. I want to create with storyboard. This view include an image. I added scrollview and added to view. But in scrollview I just showing my last view. I want to 2 view and 2 image like my view. How can i fix this?
This is my code:
import UIKit
class ViewController: UIViewController {
#IBOutlet weak var mainScrollView: UIScrollView!
var imageArray = [UIImage]()
#IBOutlet weak var myView: UIView!
#IBOutlet weak var imgv: UIImageView!
override func viewDidLoad() {
super.viewDidLoad()
imageArray = ["image","image2"]
for i in 0..<imageArray.count{
mainScrollView.contentSize.width = mainScrollView.frame.width * CGFloat(i + 1)
myView.layer.frame.size.width = myView.frame.width * CGFloat(i + 1)
imgv.image = imageArray[i]
mainScrollView.addSubview(myView)
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
}
This is storyboard and controller looks like
You are having an issue with constraints from what I see and that is why you might not see every element that you put on your storyboard. You need to correct those errors for everything to show up correctly in your scrollview. Keep in mind, you need to tell the scrollview what its height and width should be in the storyboard. They need to be defined in some way. This is a common mistake when working with scrollviews.
You can put a view in your scrollview and define its height and width property. You can set its width to be equal to the screen's width and you can set a constant for your height.

Can UITableView scroll with UICollectionView inside it?

I have the structures below...
I wrap two of collection views into tableview
One is in tableview header(Collection1), another is in tableview 1st row(Collection2).
All the functions are good (Both collection view).
just...
When I scroll up in Collection2, Collection1 will Not scroll up together, because I'm only scrolling the collectionViews not the tableview.
It only scroll together when I scroll in Collection1.
Is it possible to make the header view scroll with user just like app store's index carousel header?
Or I just went to the wrong place, I should use other ways to approach.
Solution
When you keep CollectionView1 as a TableViewHeader, CollectionView1 will always on the top of TableView after it reaches top. If you want Collection1 and Collection2 scroll up together, you need to keep CollectionView1 in a cell, not a header.
Make sure CollectionView2 content height smaller or equal to TableViewCell's height. As I checked on App Store, they always make SubCollectionView content height equal to TableViewCell's height (If they use TableView).
Result
For more detail, you can take a look at my sample project
https://github.com/trungducc/stackoverflow/tree/app-store-header
Problem
1) Your tableview cell Collectionview (let's say collection2) , Collection 2 is scrollable. So when you scroll up tableview won't scroll up
Solution
1) Just simple and working solution would be height constant , You have to give height constant to the collection2 with >= relationship and 0 Constant value and 750 priority !!
Now the question is how to use this
You need to take IBOutlet of Height constant to your custom tableview cell and need to manage the collectionview height from there.
Here is example
class FooTableViewCell: UITableViewCell {
static let singleCellHeight = 88;
#IBOutlet weak var titleLabel: UILabel!
#IBOutlet weak var descriptionLabel: UILabel!
#IBOutlet weak var iconsCollectionView: IconsCollectionView!
#IBOutlet weak var const_Height_CollectionView: NSLayoutConstraint!
var delegateCollection : TableViewDelegate?
var bars:[Bar] = [] {
didSet {
self.iconsCollectionView.reloadData()
iconsCollectionView.setNeedsLayout()
self.layoutIfNeeded()
let items:CGFloat = CGFloat(bars.count + 1)
let value = (items / 3.0).rounded(.awayFromZero)
const_Height_CollectionView.constant = CGFloat((iconsCollectionView.collectionViewLayout as! UICollectionViewFlowLayout).itemSize.height * value)
self.layoutIfNeeded()
}
}
override func awakeFromNib() {
iconsCollectionView.translatesAutoresizingMaskIntoConstraints = false
iconsCollectionView.initFlowLayout(superviewWidth: self.frame.width)
iconsCollectionView.setNeedsLayout()
iconsCollectionView.dataSource = self
iconsCollectionView.delegate = self
const_Height_CollectionView.constant = iconsCollectionView.contentSize.height
self.layoutIfNeeded()
self.setNeedsLayout()
}
}
You can check my answer Making UITableView with embedded UICollectionView using UITableViewAutomaticDimension Very similar and 100% working
Another solution You can also take UICollectionView with sections which contain another horizontal collectionview , with this solution you don't need to manage contentsize for every cell
Hope it is helpful

Swift ScrollView In UITableViewCell not scrolling

I am new to swift and am trying to add a UIScrollview to a custom UITableViewCell. I can't seem to get the scrollview to scroll in the simulator though. I have tested both vertical and horizontal scrolling.
Here is the code for my custom UITableViewCell
import UIKit
class CustomTableViewCell: UITableViewCell, UIScrollViewDelegate {
#IBOutlet weak var winLoseValueLabel: UILabel!
#IBOutlet weak var dateLabel: UILabel!
#IBOutlet weak var newTotalLabel: UILabel!
#IBOutlet weak var locationLabel: UILabel!
#IBOutlet weak var playersLabel: UILabel!
#IBOutlet weak var playersScrollView: UIScrollView!
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
self.playersLabel.text = nil
//self.playersScrollView.contentSize.height = 1000
self.playersScrollView.contentSize.width = 1000
}
override func setSelected(selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
func addLabelToScrollView(str : String) {
if self.playersLabel.text == nil{
self.playersLabel.text = str
}
else{
self.playersLabel?.text = self.playersLabel.text! + "\n\(str)"
}
}
}
My playersScrollView outlet has been properly connected to the scrollview in my storyboard. As far as I can see from all of the tutorials and sources online, I should just have to set the contentSize width or height (larger than the view area) to get it to scroll, which I have done in the awakeFromNib function.
Any ideas why this is not working in the simulator? Secondly, ideally I would like to have a vertical scrolling scrollview in the table cell, but I thought that the table view's vertical scrolling might have been interfering with the scrollview, so I changed it for horizontal scrolling for testing, which also didn't work.
Can you have a vertical scrollview in a vertically scrolling UITableView, or will the table view scrolling interfere too much with the scrollview?
Ok, it turns out that the constraints on my playersLabel, which is a subview of playersScrollView, was the culprit, although I am not sure why. I adjusted the constraints on the label and that allowed the horizontal scrolling to work.
The vertical scrolling still did not work, so I had to override the touchesBegan and touchesEnded methods in the scroll view so I could disable/re-enable the scrolling of the table view.

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