I need a label above every section in my Collection View. I\'ve tried simply dragging a label into my header space above my prototype cell, but every time I run the app, the
Implement collectionView:viewForSupplementaryElementOfKind:atIndexPath:
and supply a dequeued UICollectionElementKindSectionHeader containing your label. If this is a flow layout, be sure also to set the headerReferenceSize
or you still won't see anything.
If you want a programmatic solution in Swift 4.2, you can do the following:
Setup the UICollectionViewDelegate and UICollectionViewDelegateFlowLayout
Make custom UICollectionReusableView subclasses with whatever views you want defined. Here's one for a header, you can create another for a footer with different characteristics:
class SectionHeader: UICollectionReusableView {
var label: UILabel = {
let label: UILabel = UILabel()
label.textColor = .white
label.font = UIFont.systemFont(ofSize: 16, weight: .semibold)
label.sizeToFit()
return label
}()
override init(frame: CGRect) {
super.init(frame: frame)
addSubview(label)
label.translatesAutoresizingMaskIntoConstraints = false
label.topAnchor.constraint(equalTo: self.topAnchor).isActive = true
label.leftAnchor.constraint(equalTo: self.leftAnchor, constant: 20).isActive = true
label.rightAnchor.constraint(equalTo: self.rightAnchor).isActive = true
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
Implement the viewForSupplementaryElementOfKind method with the custom views:
func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
if kind == UICollectionView.elementKindSectionHeader {
let sectionHeader = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: "header", for: indexPath) as! SectionHeader
sectionHeader.label.text = "TRENDING"
return sectionHeader
} else { //No footer in this case but can add option for that
return UICollectionReusableView()
}
}
Implement the referenceSizeForHeaderInSection and referenceSizeForFooterInSection methods. Header method shown below for example:
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize {
return CGSize(width: collectionView.frame.width, height: 40)
}
To add the custom label above every section in UICollectionView, please follow below steps
Connect the label in the section header to the UICollectionReusableView file
class SectionHeader: UICollectionReusableView {
@IBOutlet weak var sectionHeaderlabel: UILabel!
}
In the ViewController add the below code
func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
if let sectionHeader = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: "SectionHeader", for: indexPath) as? SectionHeader{
sectionHeader.sectionHeaderlabel.text = "Section \(indexPath.section)"
return sectionHeader
}
return UICollectionReusableView()
}
Here "SectionHeader" is name of the file added to type UICollectionReusableView
From @david72's answer
You need to perform following things:
collectionView:viewForSupplementaryElementOfKind
method.For more details see here