问题
I was working on iOS application and I have several problem about using UICollectionView cell.
This time, I want to ask about how to display the section header of UICollectionView (UICollectionReusableView)
I already implement the function like below :
public func collectionView(collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, atIndexPath indexPath: NSIndexPath) -> UICollectionReusableView {
switch kind {
case UICollectionElementKindSectionHeader:
let headerView = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: "cellHeader", for: indexPath as IndexPath)
var labelHeader = headerView.viewWithTag(2) as! UILabel
if indexPath.section == 0 {
labelHeader.text = "Specialist Clinic"
}
else {
labelHeader.text = "Medical Support"
}
headerView.backgroundColor = UIColor.blue;
return headerView
default:
assert(false, "Unexpected element kind")
}
}
but, it always give a blank result. please look at the screen shot below
回答1:
You need to return size of header .
func collectionView(_ collectionView: UICollectionView,
layout collectionViewLayout: UICollectionViewLayout,
referenceSizeForHeaderInSection section: Int) -> CGSize{
return CGSize(width: CGFloat(collectionView.frame.size.width, height: CGFloat(135)) // you can change here
}
Delegate method
func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
var reusableview: UICollectionReusableView? = nil
if kind == UICollectionElementKindSectionHeader {
reusableview = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: "cellHeader", for: indexPath) // cellHea is your identifier
var labelHeader = reusableview.viewWithTag(2) as! UILabel
if indexPath.section == 0 {
labelHeader.text = "Specialist Clinic"
}
else {
labelHeader.text = "Medical Support"
}
headerView.backgroundColor = UIColor.blue;
}
return reusableview!
}
回答2:
I have created demo for you. Download and re-use into your code. Cheers!
Download Link : https://www.dropbox.com/sh/vzf2tpe0ccf41tv/AABjdPAoaP2sE7YRtUgersq4a?dl=0
回答3:
You need to add UILabel on headerView
public func collectionView(collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, atIndexPath indexPath: NSIndexPath) -> UICollectionReusableView {
switch kind {
case UICollectionElementKindSectionHeader:
let headerView = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: "cellHeader", for: indexPath as IndexPath)
var labelHeader = headerView.viewWithTag(2) as! UILabel
if indexPath.section == 0 {
labelHeader.text = "Specialist Clinic"
}
else {
labelHeader.text = "Medical Support"
}
headerView.backgroundColor = UIColor.blue;
headerView.addSubview(labelHeader) //Add UILabel on HeaderView
return headerView
default:
assert(false, "Unexpected element kind")
}
}
来源：https://stackoverflow.com/questions/44694923/display-section-header-uicollectionreusableview