Data has been replaced or missing while scrolling collectionview - ios

Question

i am implementing collection view as my ChatMessagViewController and i am populating message in collectionview all things works perfect for me but issue is that when i scrolled collection view message was . issing or replaced on scroll let me show you my code for populating collectionview
here i am adding screen shot for what output i get before scrolling and after scrolling please have a look
func loadMessageData(){
self.message.removeAll()
guard let uid = Auth.auth().currentUser?.uid else{
return
}
let userref = Database.database().reference().child("Message").child(uid)
userref.child(self.senderID!).observe(.childAdded, with: { (snapshot) in
print(snapshot)
if let dictonary = snapshot.value as? [String:AnyObject]{
let key = snapshot.key
let mainDict = NSMutableDictionary()
mainDict.setObject(key, forKey: "userid" as NSCopying)
self.namesArray.add(mainDict)
let message = Message(dictionary: dictonary)
self.message.append(message)
self.timer?.invalidate()
self.timer = Timer.scheduledTimer(timeInterval: 0.1, target: self, selector: #selector(self.handleReload), userInfo: nil, repeats: false)
}
}, withCancel: nil)
}
extension ChatViewController: UICollectionViewDelegate,UICollectionViewDataSource,UICollectionViewDelegateFlowLayout{
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return message.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellID, for: indexPath) as! ChatMessageCell
let message1 = message[indexPath.item]
cell.tetxtView.text = message1.msg
cell.bubbleWidthAnchor?.constant = estimatedFrameForText(text: message1.msg!).width + 32
let ketID = message1.key_id
if ketID == Auth.auth().currentUser?.uid{
cell.bubbleView.backgroundColor = UIColor(red: 255, green: 255, blue: 255, alpha: 1)
cell.bubbleViewRightAnchor?.isActive = false
cell.bubbleViewLeftAnchor?.isActive = true
}else{
cell.bubbleView.backgroundColor = UIColor(red: 0/255, green: 158/255, blue: 214/255, alpha: 1)
cell.tetxtView.textColor = UIColor.white
cell.bubbleViewRightAnchor?.isActive = true
cell.bubbleViewLeftAnchor?.isActive = false
}
return cell
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
var height: CGFloat = 80
if let mesg = message[indexPath.item].msg{
height = estimatedFrameForText(text: mesg).height + 20
}
return CGSize(width: view.frame.width, height: height)
}
}
and here is the collectionview methods for populating
issue is that when i scroll the message was replaced or missing
please check screen shot first i am getting messages and after scrolling i came back to top message is missing

Answer 1

cell.tetxtView.textColor is dequeued make sure to add it inside the if also
if ketID == Auth.auth().currentUser?.uid{
cell.bubbleView.backgroundColor = UIColor(red: 255, green: 255, blue: 255, alpha: 1)
cell.tetxtView.textColor = UIColor.black /////// here
cell.bubbleViewRightAnchor?.isActive = false
cell.bubbleViewLeftAnchor?.isActive = true
}else{
cell.bubbleView.backgroundColor = UIColor(red: 0/255, green: 158/255, blue: 214/255, alpha: 1)
cell.tetxtView.textColor = UIColor.white
cell.bubbleViewRightAnchor?.isActive = true
cell.bubbleViewLeftAnchor?.isActive = false
}
The text color is white so it same as the background of it's superview , hence doesn't appear