UICollectionView - add bottom inset for entire collectionView - ios

I have a UICollectionView with multiple sections.
I would like to add bottom inset to the entire collectionView.
All the Q&As suggest to use the following function:
func collectionView(_ collectionView: UICollectionView,
layout collectionViewLayout: UICollectionViewLayout,
insetForSectionAt section: Int) -> UIEdgeInsets
But this adds insets to all the sections. Where I need space only it the bottom of the collectionView

You can try
collectionView.contentInset = UIEdgeInsets(top: 0, left: 0, bottom:<#someValue#>, right: 0)

Related

CollectionViewCell's container view doesn't fill cell

I have a collectionView who's height and width I set with constraints using autolayout.
In my
func collectionView(_ collectionView: ...., sizeForItemAt indexPath: IndexPath) I return CGSize(width: self.collectionView.frame.width-20, height: self.collectionView.frame.height) and as seen on the image linked below it lines up perfectly fine.
The problem is that the container view (white space) of that cell doesn't fill up the green space (that is the cell's background) at all even though I have set constraints of the containerView to hug left/right/bottom/up with 0 margin.
What I have tried so far:
Make a height constraint for the container view that I assign the collection view's height
updateConstraints() in cellForItemAt and inside the cell's class in ```layoutSubview()````
Set the container view's frame to the collectionView's frame
cell.layoutIfNeeded()in cellForItemAt
None of these have solved my problem.
https://i.stack.imgur.com/mD2iC.jpg
Here issue related to inset I think. Please use collection delegate method
- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section{
return UIEdgeInsetsMake(top, left, bottom, right);
}
or
UICollectionViewFlowLayout *aFlowLayout = [[UICollectionViewFlowLayout alloc] init];
[aFlowLayout setSectionInset:UIEdgeInsetsMake(top, left, bottom, right)];
Swift 5.1
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
return 15.0
}

Displaying two cells per row in CollectionView Swift

I am trying to set my collection view cell sizes so that I get two cells per row.
I have looked at plenty of solution for sizing cells for collection views. I actually have used some solutions before for sizing three cells per row that have worked for me.
What I have so far:
extension BusinessViewController: UICollectionViewDelegateFlowLayout {
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
let width = (view.frame.width - 20) / 2.0
return CGSize(width: width, height: width)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
return UIEdgeInsets(top: 5, left: 5, bottom: 5, right: 5)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
return 10
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
return 10
}
}
Right now I just get one big cell per row and I don't know why. Usually when I have to have 3 cells per row, simply subtracting the insets from the views width and dividing by the number of desired cells is enough. Not sure why this is causing me an issue.
You can try checking the "estimatesSize" property of UICollectionView.
It could have been set to "Automatic" instead of "None".
I solved the same problem with this solution

How to remove space between section in UICollectionView swift

I have a UICollectionView with two section. In first, it has UIPageControl and in second simple UICollectionView.
Between first and second element it has spacing, can you suggest me how to remove that?
Platform iOS 9.*, Swift 3
You can specify the UIEdgeInsets of the collection view to solve this problem
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
return UIEdgeInsetsMake(0, 0, 0, 0)
}

Setting minimumLineSpacing for UICollectionViewFlowLayout has no effect, must use insetForSectionAtIndex function?

The goal is to define the spacing between sections for a UICollectionView.
However, setting the UICollectionViewFlowLayout as follows with the minimumLineSpacing property has no effect:
// Init <collectionView>
collectionView.alwaysBounceVertical = true
collectionView.contentInset = UIEdgeInsets(top: CollectionViewTopPadding, left: 0, bottom: CollectionViewBottomPadding, right: 0)
let flowLayout = collectionView.collectionViewLayout as! UICollectionViewFlowLayout
flowLayout.minimumLineSpacing = 5
The only approach that's working is to use the insetForSectionAtIndex as follows:
func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAtIndex section: Int) -> UIEdgeInsets {
return UIEdgeInsets(top: 5, left: 0, bottom: 0, right: 0)
}
Other examples on SO set minimumLineSpacing so can anyone explain why this code isn't working?
According to Apple documentation
The flow layout uses the value in minimumLineSpacing property to set the spacing between lines in a section.
Thus it will not set spacing between the sections, it is for setting space between the rows/columns within the section. If at all you want to achieve spacing between sections without implementing delegate method, you could use sectionInset property of UICollectionViewFlowLayout.
Incase someone is wondering how to only do it for one section:
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
if section == 0{
return UIEdgeInsetsMake(0, 0, 10, 0)
}
return UIEdgeInsetsMake(0, 0, 0, 0)
}

Placing the cells in a collection view in the centre rather than the outsides in swift

By default, a collection view will attempt to space out the cells in the collection by spacing them evenly so that there will be one cell touching either side of the collection view. Example:
But, when the cell is too wide to fit multiple cells in one row on the collection view, it will centre the cell in the collection view.
Is there a way to make the behaviour of centring cells, like in the 3rd picture, the default for the collection view so that there is 0 space between the individual cells and space on either side to the edges of the collection view?
Not that I'm aware of. You should implement something like this:
func collectionView(_ collectionView: UICollectionView,
layout collectionViewLayout: UICollectionViewLayout,
sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
CGFloat width = UIScreen.mainScreen().bounds.size.width
return CGSize(width, anyHeight)
}
and then implement the delegate method below as well:
func collectionView(collectionView: UICollectionView,
layout collectionViewLayout: UICollectionViewLayout,
insetForSectionAtIndex section: Int) -> UIEdgeInsets {
return UIEdgeInsetsZero
}
Make sure to implement rotation handling too if it's applicable.
My answer would be to use a carefully set up something like
let insets = UIEdgeInsets(top: yourvalues, left: yourvalues, bottom: yourvalues, right: yourvalues),
and feed it to either YourCollectionView.contentInset, or
func collectionView(collectionView: UICollectionView,
layout collectionViewLayout: UICollectionViewLayout,
insetForSectionAtIndex section: Int) -> UIEdgeInsets {
return sectionInsets
}
This should work! Lemme know if you have any troubles with it!

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