UITableView background colour for bottom 5 rows - ios

Question

I do know how to input background colours for my row, but I don't really know how I can filter it by only the bottom 5 rows are "cell.backgroundColor = UIColor.red;" whereas the rest stays the same. Appreciate those who can help me this thanks!
P.S: Sorry as my swift is quite rusty.
UITableView Controller
import UIKit
import FirebaseDatabase
var postData2 = [String]()
var postData3 = [String]()
var tableDataArray = [tableData]()
class ResultsController: UITableViewController {
override func viewDidLoad() {
super.viewDidLoad()
ref = Database.database().reference() //set the firebase reference
// Retrieve the post and listen for changes
databaseHandle = ref?.child("Posts3").observe(.value, with: { (snapshot) in
postData2.removeAll()
postData3.removeAll()
tableDataArray.removeAll()
for child in snapshot.children {
let snap = child as! DataSnapshot
let key = snap.key
let value = String(describing: snap.value!)
let rating = (value as NSString).integerValue
postData2.append(key)
postData3.append(value)
tableDataArray.append(tableData(boothName: key, boothRating: rating))
}
postData2.removeAll()
postData3.removeAll()
let sortedTableData = tableDataArray.sorted(by: { $0.boothRating > $1.boothRating })
for data in sortedTableData {
postData2.append(data.boothName)
let value = String(describing: data.boothRating)
postData3.append(value)
}
self.tableView.reloadData()
})
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return postData2.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
cell.textLabel?.font = UIFont.init(name: "Helvetica", size: 23)
cell.textLabel?.text = postData2[indexPath.row]
cell.detailTextLabel?.text = postData3[indexPath.row] + " ♥"
cell.detailTextLabel?.textColor = UIColor.red;
cell.detailTextLabel?.font = UIFont.init(name: "Helvetica", size: 23)
// cell.backgroundColor = UIColor.red;
return cell
}
override func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat
{
return 80
}
}
class tableData {
var boothName: String
var boothRating: Int
init(boothName: String, boothRating: Int) {
self.boothName = boothName
self.boothRating = boothRating
}
}

Answer 1

A simple way is to have an conditional check to see if the indexPath.row value is within the last five.
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
if(indexPath.row >= postData2.count-5){
cell.backgroundColor = UIColor.red
}else{
cell.backgroundColor = UIColor.white /* Remaining cells */
}
return cell
}

Answer 2

Some of the other answers will work - but it is nicer to use cells that have a known configuration when they are dequeued by cellForRowAt, not deal with a bunch of possible starting conditions each time you dequeue a cell. To do this subclass the UITableViewCell and override prepareForReuse(). This function will be called just before a cell is returned by dequeueReusableCell. Then cells can be set to a known starting point before you configure them. If cells could be received configured any possible way in cellForRowAt, you soon wind up with a very long function with a lot of if/else conditions.
The condition
if indexPath.row >= postData2.count - 5 {
cell.backgroundColor = UIColor.red
}
can be used as it is, and prepareForReuse takes care of the cells not keeping any settings when they are recycled. Here's an example:
override func prepareForReuse() {
super.prepareForReuse()
backgroundColor = UIColor.white
}
With this one simple setting it's a wash whether you do the if/else approach or use subclassing to make the most of prepareForReuse. But as soon as you have more than one thing to set in a cell you will find it is far less complex to use this function and results in far fewer mistakes with the appearance of cells - consider what would happen if there were more than one possible color a cell could be, or there were multiple elements in the cell to be configured with multiple possible values...

Answer 3

You can add simple logic
if indexPath.row >=(postData2.count-5) {
cell.backgroundColor = UIColor.red
}else {
cell.backgroundColor = UIColor.white
}

Answer 4

Just check a condition for setting the red colour for last five rows.
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
if(indexPath.row >= postData2.count-5){
cell.backgroundColor = UIColor.red;
}else {
cell.backgroundColor = UIColor.white; //white colour for other rows
}
return cell
}

Answer 5

This method is recommended by the system, this method is more circumventing reuse in some cases (like when you modify the contents of a control in the cell surface)
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
var cell: UITableViewCell? = tableView.dequeueReusableCell(withIdentifier: "cell")
// Not the type of cell, if the queue will return nil, at this time requires create ⼀ cell
if cell == nil {
cell = UITableViewCell(style: .default, reuseIdentifier: "cell")
}
}
If it involves data processing, you can create a new NSMutableSet(), Used to store your operations (ordinary data is lost, stored in the didSelecetRow inside indexPath like) save anyway, a unique tag.
These are just solve the problem of multiplexing, to deal with discoloration, refer to the above solution.
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
if(indexPath.row >= postData2.count-5){
cell.backgroundColor = UIColor.red
}else{
cell.backgroundColor = UIColor.white /* Remaining cells */
}
return cell
}