I have a collectionview covering the whole screen. I want to use the collectionview so that all cells are visible at the same time which means that the height gets set dynamically. And as a plus: It should work in portrait and landscape.
In the past I solved it like this:
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize
{
let heightOffset = (UIDevice.current.orientation.isPortrait) ? CGFloat(30) : CGFloat(0)
let width = UIScreen.main.bounds.width
let height = UIScreen.main.bounds.height - heightOffset
return CGSize(width: width, height: height / CGFloat(mainScreenItems.count))
}
But on iPhoneX I get problems, because the offset is not correct. Even if I take the height of the collectionview frame it doesn't work correctly.
Related
I have a UICollectionView with a custom cell, however, I am trying to impose constraints on the UICollectionView, so it is always half the width of the screen and half the height of the screen. The one issue I continually encounter is that while the UICollectionView changes according to what device the app is deployed on, the UICollectionViewCells hold the exact same pixel width and height dimensions. This is the code I have tried to implement to make each cell the same height and width as the CollectionView.
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
let height = collectionView.frame.height
let width = collectionView.frame.width
return CGSize(width: width, height: height)
}
This code, however, doesn't work as the size of the cells are simply the values that are specified in the size inspector for the UICollectionView.
I'm unable to figure out what I am doing wrong here with my code. Thank you very much in advance for your help.
The issue is your collection view cell size is fixed always. So the cell size is not adjust according to screen size.Use view frame size.(remove values from size inspector)
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: view.frame.width, height: view.frame.height)
}
I have a UICollectionView and I have implemented the delegate to calculate the width of my cells for 0 spacing between cells.
It works great on its own, but when I have it inside a container view less than the size of the device, iOS incorrectly works out the spacing between the cells adding a horizontal space I don't want.
I have verified the width I am using to calculate the cell size is correct, so I'm not sure what is causing the problem.
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
let widthPerItem = view.frame.width / itemsPerRow
return CGSize(width: widthPerItem, height: 60)
}
You are calculating your cell size based upon the size of the view. Since the collectionView doesn't take up the full width of the screen, you are getting the incorrect value. Instead, you should base your calculation on the width of the collectionView itself.
Use the bounds of the collectionView instead of the frame of the view:
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
let widthPerItem = collectionView.bounds.width / itemsPerRow
return CGSize(width: widthPerItem, height: 60)
}
Ok, the problem was actually related to my uicollectionviewcontroller not correctly sizing to it's parent container view. Changing to a uiviewcontroller with an embedded uicollectionview plus constraints fixed the problem.
I want to use collection view for show user's instagram photos like Tinder. I placed a collectionview and enabled paging. But i don't know how to show 6 photos for each page. How can i do this?
This is what i want:
First page:
Second Page:
I used all spacing settings zero because setting spacing from storyboard problem for different screen sizes.
My collection view's settings and result:
Result:
So i want to show 6 photos per page. How to achive this?
To show the specific number of cells you want, you have to calculate the size of the cells. Something like this:
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
let numberOfRows = 2
let numberOfColumns = 3
let height = collectionView.frame.size.height / numberOfRows
let width = collectionView.frame.size.width / numberOfColumns
let cellSize = CGSize(width: width, height: height)
return cellSize
}
Since your layout configuration is static you can calculate it just once to make it faster:
class MyVC: UIViewController {
private let cellSize: CGSize = CGSize(width: collectionView.frame.width/numberOfColumns, height: collectionView.frame.height/numberOfRows) // or create a computed property
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return cellSize
}
}
This code is untested, maybe you have to add some padding but you get the idea. Another option would be to implement your own UICollectionViewLayout subclass
This might be a simple question -- I'm new to iOS Development.
I have a homepage with a Collection View with four cells that take up the whole screen (top left, top right, bottom left, bottom right) in portrait mode. In landscape mode, I want all four cells to be side by side in a row.
Is Collection View the right layout to use? Should I use Autoresizing to do this, or do I have to use some other layout constraints?
Thank you!
UICollectionView is the right layout to use.
you can use the following for making layout
func collectionView(collectionView: UICollectionView,
layout collectionViewLayout: UICollectionViewLayout,
sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
let flowLayout = collectionViewLayout as! UICollectionViewFlowLayout
let totalSpace = flowLayout.sectionInset.left
+ flowLayout.sectionInset.right
+ (flowLayout.minimumInteritemSpacing * CGFloat(4 - 1))
let size = Int((collectionView.bounds.width - totalSpace) / CGFloat(4))
return CGSize(width: size, height: size)
}
Following way you can use it inside your view controller
class ViewController: UIViewController, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout {
#objc(collectionView:layout:sizeForItemAtIndexPath:)
func collectionView(_ collectionView: UICollectionView,
layout collectionViewLayout: UICollectionViewLayout,
sizeForItemAt indexPath: IndexPath) -> CGSize {
let flowLayout = collectionViewLayout as! UICollectionViewFlowLayout
let totalSpace = flowLayout.sectionInset.left
+ flowLayout.sectionInset.right
+ (flowLayout.minimumInteritemSpacing * CGFloat(4 - 1))
let size = Int((collectionView.bounds.width - totalSpace) / CGFloat(4))
return CGSize(width: size, height: size)
}
}
it should be a merge beetween UIStackView and Sizeclasses
the stackviews have to have fill equaly distribution.
the selected stackview has to have axis vertical by default, but you should add horizontal axis sizeclass width regular | height any
I have a collectionView with horizontal UICollectionViewFlowLayout.
I am trying to achieve:
If a device orientation is portrait, UIImageView width will be qual to view.width and let the height be calculated automatically (like it usually happens with Auto Layout). And the same for the landscape mode. Example - standard photo app on the Iphone.
Unfortunately i don't see how to achieve it with autoLayout. I set constraints on UIImageView for it to be equal in size to the cell. But looks like the sell itself cannot be pinned to the Parent View.
After reading similar questions looks like cells must be resized programmatically using
func collectionView(collectionView: UICollectionView,
layout collectionViewLayout: UICollectionViewLayout,
sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
return CGSize(width: width, height: height)
}
And here i am stuck because i know the width of the screen but don't know how to calculate the height dynamically.
About image height:
I have my image declared like this:
var pageImages = [UIImage]()
override func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell: ImageDetailViewCell = collectionView.dequeueReusableCellWithReuseIdentifier(reuseIdentifier, forIndexPath: indexPath) as! ImageDetailViewCell
let curr = indexPath.row
let imgName = data[albumNumber][curr]["image"]
cell.DetailImageView.image = UIImage(named: imgName!)
return cell
}
If you use the proper UIImageView resize setting (say, aspect fit/fill), then you just need to set the cell's height to your collectionView's (you get a pointer to it as one of the ...sizeForItemAtIndexPath... method parameters) height. You also should call the - layoutIfNeeded method on your cell afterwards.
You can use sizeForItemAtIndexPath: to change the size of collection view cell.
func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
var numberOfCellInRow : Int = 3
var padding : Int = 5
var collectionCellWidth : CGFloat = (self.view.frame.size.width/CGFloat(numberOfCellInRow)) - CGFloat(padding)
return CGSize(width: collectionCellWidth , height: collectionCellWidth)
}
You can get the size of cell via :
((UICollectionViewFlowLayout) self.collectionViewName).itemSize.height)
You can get the image size via :
let sizeOfImage = image.size
let height = image.height
If you want to change the height then change it manually by return CGSize(width: collectionCellWidth , height: cellheight)