Hey guys I’d love some help on an issue I am facing with uicollection view. It’s a uicollectionview inside a .xib with custom cells that I’m loading through UINibs. I almost get the result I’m looking for but there’s some awkward spacing. Also as a note I’m using the layout delegate to calculate the size of the text and then setting the cell but it’s still awkward every time I generate it. Thanks guys.
Example 1
Example 2
Here is the code I am using:
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
// dataArary is the managing array for your UICollectionView.
let item = self.visibleSuggestion[indexPath.item]
var itemSize = item.size(withAttributes: [
NSAttributedString.Key.font : UIFont.boldSystemFont(ofSize: 13)
])
itemSize.width += 20
itemSize.height += 15
return itemSize
}
Related
I have implemented UICollectionView with the vertical scrolling and paging, first image showing properly but after scrolling layout get changed.
Code -
// MARK: - UICollectionViewDelegateFlowLayout
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: self.collectionView.frame.width, height: self.collectionView.frame.height)
}
I enable the paging from UICollectionView
Also attached images below.
Thanks in advance.
pls check below screen sort setting of collectionview into storyboard.
Estimate size none
others min spacing for cells & for lines are zero or not
I am currently trying to resize my cell within my CollectionView. I have already implemented the dataSource, CollectionViewDelegate and CollectionViewDelegateFlowLayout.
This is the code I have for the latter:
extension ViewController: UICollectionViewDelegateFlowLayout {
func collectionView(_ collectionView: UICollectionView, layout
collectionViewLayout: UICollectionViewLayout, sizeForItemAt
indexPath: IndexPath) -> CGSize
{
return CGSize(width: 100.0, height: 100.0)
}
}
The problem is that when I head over to my storyboard and select my CollectionView and then go to the Attributes Inspector to switch "Estimate Size" from "Automatic" to "None," I would get three columns after running my app [Image #1].
The result I am looking for is to be able to have one middle column with a bigger cell as I show on Image #2.
Has anybody dealt with this problem before?
In order to show a collection view cells as a list, you can change your cell width equals to the width of the collection view. Giving constant width will not work for different device size.
func collectionView(_ collectionView: UICollectionView, layout
collectionViewLayout: UICollectionViewLayout, sizeForItemAt
indexPath: IndexPath) -> CGSize
{
let width = collectionView.frame.width
return CGSize(width: width, height: 100.0)
}
}
And give your desired constraint values for the inner rectangular view to achieve the desired look. Make collectionView cell background to clear.
I don't know why but the cells of my collectionView are automatically wrongly resized after a reloadData.
After first init, then after reloadData :
I'm using UICollectionViewDelegateFlowLayout to define the size of the cell but it don't take care of it :
func collectionView(_ collectionView: UICollectionView,
layout collectionViewLayout: UICollectionViewLayout,
sizeForItemAt indexPath: IndexPath) -> CGSize {
let paddingSpace = sectionInsets.left * (2 + 1)
let availableWidth = view.frame.width - paddingSpace
let widthPerItem = availableWidth / 2
return CGSize(width: widthPerItem, height: widthPerItem)
}
func collectionView(_ collectionView: UICollectionView,
layout collectionViewLayout: UICollectionViewLayout,
insetForSectionAt section: Int) -> UIEdgeInsets {
return sectionInsets
}
func collectionView(_ collectionView: UICollectionView,
layout collectionViewLayout: UICollectionViewLayout,
minimumLineSpacingForSectionAt section: Int) -> CGFloat {
return sectionInsets.left
}
When execution come in the cellForItemAt, the cell have the right size, the shadow is created in this function and it have the right width.
One last thing is that only the width is resized, the height stay as I want.
Does any one have an idea why the width is resized wrongly after the reloadData ?
I was having a similar issue when making an extension of the UICollectionViewDelegateFlowLayout and it turns out that setting the collectionView's Estimated Size to "None" in the storyboard (Size Inspector) solved it.
As stated in the Xcode 11 Release Notes:
Cells in a UICollectionView can now self size with Auto Layout
constrained views in the canvas. To opt into the behavior for existing
collection views, enable “Automatic” for the collection view’s
estimated size, and “Automatic” for cell’s size from the Size
inspector.
If deploying before iOS 13, you can activate self sizing collection
view cells by calling performBatchUpdates(_:completion:) during
viewDidLoad(). (45617083)
So, newly created collectionViews have the attribute "Estimated Size" set as "Automatic" and the cell's size is computed considering its subview dimensions, thus ignoring the UICollectionViewDelegateFlowLayout extension methods, even though they are called.
I am trying to do some horizontal collection view with dynamic height of each cell. Like citymapper does when you have aready choosen a trip. ¿Has anyone got any idea of how to do this? Even though if it's not with a collection view.
Video of the behaviour
One way of doing this is implementing the UICollectionViewDelegateFlowLayout of the collectionView.
One of the methods of this delegate is final public func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize. Here you can return the size of the collectionCell depending on the content or whatever you use to determinate the height.
Hope it helps.
The horizontal scrolling in UICollectionView only returns one row and I need to make a horizontal scrolling collection view with 2 rows just like the image below
[1]: https://i.stack.imgur.com/Vs1kt.png :[1]
You need to set fix height of the CollectionView and then use sizeForItemAt() under UICollectionViewDelegateFlowLayout which returns CGSize. You have to manage the cell height something like this.
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: 50.0, height: collectionViewHeight / 2) //<-- Manage height and width accordingly.
}