How to reuse cells in a UITableView? - ios

Question

I'm running into some problems today in my application. I'm using a UITableView to present different cells some contain a specific button, some display a game your currently in, some are just for spacing between cells.
However im running into some problems when I do tableView.reloadData().
When I click on 'new game' a new game cell should be added, but instead of that the last cells are moved down (like expected, because something comes in between), however the upper cells that should change, they don't. I expect this to be because of reusing (or "caching"). Maybe someone can help me out on how to fix this.
Here is an image of what is happening explanation
Now I have different cells, all with their own Identifiers for example: "Emptycell", "Gamecell", "startnewgameBtnCell". I do this because I create each cell in storybuilder.
here is my code for cellForRowAtIndexPath
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = UITableViewCell()
let identifier = cell_identifiers[indexPath.row][0] as! String
if ((cell_identifiers[indexPath.row][1] as! String) == "MYTURN" ) {
var cell = tableView.dequeueReusableCellWithIdentifier(identifier, forIndexPath: indexPath) as! GameViewCell
let match = self.myTurnMatches[indexPath.row - 4]
setupGameViewCellObject(match)
}
if ((cell_identifiers[indexPath.row][1] as! String) == "NOT" ) {
var cell = tableView.dequeueReusableCellWithIdentifier(identifier, forIndexPath: indexPath) as! FirstMenuTableViewCell
}
return cell
In this code I check if its a gamecell or not, emptycells or cells that contain a label or button are all FirstMenuTableViewCell. Only GameCell have their own class GameViewCell.
I have also double checked to see if my identifiers are build up correctly and they are.
Maybe someone can explain me exactly whats happening and what might be the correct approach to solve the situation I'm in, I think I may not fully understand how to use UITableViewCell with custom cells.
Thanks for reading

Answer 1

You create new variables called cell in the if statements. You are hiding the outer cell.
Use one cell variable.
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
var cell: UITableViewCell
let identifier = cell_identifiers[indexPath.row][0] as! String
if ((cell_identifiers[indexPath.row][1] as! String) == "MYTURN" ) {
cell = tableView.dequeueReusableCellWithIdentifier(identifier, forIndexPath: indexPath) as! GameViewCell
let match = self.myTurnMatches[indexPath.row - 4]
setupGameViewCellObject(match)
}
if ((cell_identifiers[indexPath.row][1] as! String) == "NOT" ) {
cell = tableView.dequeueReusableCellWithIdentifier(identifier, forIndexPath: indexPath) as! FirstMenuTableViewCell
}
return cell
}

Answer 2

Try update your code:
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = UITableViewCell()
let identifier = cell_identifiers[indexPath.row][0] as! String
if ((cell_identifiers[indexPath.row][1] as! String) == "MYTURN" ) {
var cell = tableView.dequeueReusableCellWithIdentifier(identifier, forIndexPath: indexPath) as! GameViewCell
let match = self.myTurnMatches[indexPath.row - 4]
setupGameViewCellObject(match)
return cell
}
if ((cell_identifiers[indexPath.row][1] as! String) == "NOT" ) {
var cell = tableView.dequeueReusableCellWithIdentifier(identifier, forIndexPath: indexPath) as! FirstMenuTableViewCell
return cell
}
return cell
if me, i coded:
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let identifier = cell_identifiers[indexPath.row][0] as! String
if ((cell_identifiers[indexPath.row][1] as! String) == "MYTURN" ) {
let cell = tableView.dequeueReusableCellWithIdentifier(identifier, forIndexPath: indexPath) as! GameViewCell
let match = self.myTurnMatches[indexPath.row - 4]
setupGameViewCellObject(match)
return cell
}else { // if you sure just have 2 cell type
let cell = tableView.dequeueReusableCellWithIdentifier(identifier, forIndexPath: indexPath) as! FirstMenuTableViewCell
return cell
}
}
But i think you should use section in tableview,it is better. So, you have 3 section, and 2 headerofsection in there. the first section have 1 row, the second have self.myTurnMatches.count row.... :
override func tableView(tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
if section == 0 || section == 1{
return 44
}else{
return 0
}
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
if indexPath.section == 1{
let cell = tableView.dequeueReusableCellWithIdentifier("GameViewCell 's identifier", forIndexPath: indexPath) as! GameViewCell
let match = self.myTurnMatches[indexPath.row - 4]
setupGameViewCellObject(match)
return cell
}else{
let cell = tableView.dequeueReusableCellWithIdentifier("FirstMenuTableViewCell 's identifier", forIndexPath: indexPath) as! FirstMenuTableViewCell
return cell
}
}