View reappears in UITableViewCell after scrolling off and on - ios

Question

I have a UITableView with 2 sections. In the first section I do not want the UIView I have created to appear on the left. It works fine when it initially loads but when it goes off screen and back on again it reappears.
func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath)
{
let cell = tableView.dequeueReusableCell(withIdentifier: "reuseIdentifier") as! ATableCell;
cell.delegate = self;
if (indexPath.section == 1)
{
// let height = cell.bounds.size.height;
let height = 100;
let turnsView = UIView(frame: CGRect(x: 0, y: 0, width: 10, height: height));
turnsView.backgroundColor = UIColor.purple;
cell.addSubview(turnsView);
}
else
{
let height = 100;
let turnsView = UIView(frame: CGRect(x: 0, y: 0, width: 10, height: height));
turnsView.backgroundColor = UIColor.clear;
cell.addSubview(turnsView);
}
// Configure the cell...
cell.backgroundColor = UIColor.clear;
cell.textLabel?.text = "texting";
cell.detailTextLabel?.text = "testing";
}
I don't want the purple view appearing in the first section at any point.

Answer 1

When using
tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
You should use Every "if" condition with its "else" clause as when you scroll on off it reuses the cell that cause it to reappear. So if you not write else condition and if condition become false it will use old cell data.

Answer 2

Always avoid adding subviews to cell in cellForRow. You need to understand that the cells are reused and when you add the subView in cellForRow, the subView is not removed each time. So if the cell appears for 10 times due to scrolling on and off, 10 subViews would be added to the reused cell.
In your case same thing is happening. I would suggest you to add the view in XIB/Prototype cell. Give it a reference and change its backgroundColor property in cellForRow.
Or if you are not using XIB or prototype cell, add subview in init method in your cell class.
var turnsView = UIView()
override init(style: UITableViewCellStyle, reuseIdentifier: String!) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
turnsView = UIView(frame: CGRect(x: 0, y: 0, width: 10, height: 100))
self.contentView.addSubview(turnsView)
}

Answer 3

This should work for you:
func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath)
{
let cell = tableView.dequeueReusableCell(withIdentifier: "reuseIdentifier") as! ATableCell;
cell.delegate = self;
//Remove subviews before adding again
if let purpleV = cell.viewWithTag(1) {
purpleV.removeFromSuperview()
}
if let purpleV = cell.viewWithTag(2) {
purpleV.removeFromSuperview()
}
if (indexPath.section == 1)
{
// let height = cell.bounds.size.height;
let height = 100;
let turnsView = UIView(frame: CGRect(x: 0, y: 0, width: 10, height: height));
turnsView.tag = 1
turnsView.backgroundColor = UIColor.purple;
cell.addSubview(turnsView);
}
else
{
let height = 100;
let turnsView = UIView(frame: CGRect(x: 0, y: 0, width: 10, height: height));
turnsView.tag = 2
turnsView.backgroundColor = UIColor.clear;
cell.addSubview(turnsView);
}
// Configure the cell...
cell.backgroundColor = UIColor.clear;
cell.textLabel?.text = "texting";
cell.detailTextLabel?.text = "testing";
}
Read the documentation for dequeuereusablecell method to clarify.

Answer 4

This will be good to do as:
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "reuseIdentifier", for: indexPath)
// Config the cell...
if let turnsCell as? ATableCell {
turnsCell.turnsColor = (indexPath.section == 1 ? UIColor.purple : UIColor.clear)
}
cell.textLabel?.text = "texting"
cell.detailTextLabel?.text = "testing"
return cell
}
class ATableCell: UITableViewCell {
var turnsView = UIView()
var turnsColor: UIColor {
get {
return self.turnsView.backgroundColor
}
set {
self.turnsView.backgroundColor = newValue
}
}
override func awakeFromNib() {
super.awakeFromNib()
// let height = self.bounds.size.height;
let height = 100;
turnsView.frame = CGRect(x: 0, y: 0, width: 10, height: height)
self.contentView.addSubview(turnsView)
self.backgroundColor = UIColor.clear
}
}