My Tableview is reusing previous cell image data and displaying images from previous cells. I did the following to prevent it from reusing. What am I missing?
#IBAction func cityBtn(_ sender: UIButton) {
for i in stride(from: 0, to: assignCities.count, by: 1)
{ cityName.append(bigCities[i])
cityImages.append(bigCityImages[i])
}}
public func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let myCell= tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! CityCell
myCell.myLabel.text = cityName[indexPath.row]
let cityImg = cityImages[indexPath.row]
myCell.myImage.image = nil
if (cityImg != "")
{
myCell.myImage.image = UIImage(named:cityImg)
}
else
{
myCell.myImage.image = nil
}
return myCell
}
import UIKit
class CityCell: UITableViewCell {
#IBOutlet weak var myImage: UIImageView!
#IBOutlet weak var myLabel: UILabel!
override func prepareForReuse() {
super.prepareForReuse()
myImage.image = nil
}
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
}
I did the above but still it is not getting the result
You can implement func prepareForReuse() method of UITableViewCell and reset your cell properties there.
This method is invoked just before the object is returned from the UITableView method dequeueReusableCell(withIdentifier:)
func prepareForReuse() {
super. prepareForReuse()
myImage.image = nil
}
This had to be implemented inside your custom table view cell class.
If there ara not so many cells in your tableView,maybe you can use unique CellIdentifier,such as: indexPath.section_indexPath.row
Related
I am trying to instantiate empty Buyer cells (custom cell) in my table view and then have the user populate the buyers' names. When the user presses the delete button for a row/cell, it should delete the corresponding row/cell regardless of whether or not the textfield for that row has been populated or not. Clearly, I am not getting the desired behavior. For example, when I press delete Row0 (whose textfield says "Buyer 0") and the tableview reloads, Buyer 0 is still there, but one of the empty Buyer cells at the end gets deleted instead.
import UIKit
class EntryAlertViewController: UIViewController {
//Fields/Table
#IBOutlet weak var itemField: UITextField!
#IBOutlet weak var priceField: UITextField!
#IBOutlet weak var tableView: UITableView!
//Visual Components
#IBOutlet weak var mainView: UIView!
#IBOutlet weak var titleView: UIView!
#IBOutlet weak var splitItemButton: UIButton!
#IBOutlet weak var cancelButton: UIButton!
#IBOutlet weak var addItemButton: UIButton!
//Commonly Used Objects/Variables
var potentialBuyers: [String] = []
override func viewDidLoad() {
super.viewDidLoad()
potentialBuyers.append("")
tableView.dataSource = self
tableView.register(UINib(nibName: "BuyerCell", bundle: nil), forCellReuseIdentifier: "ReusableCell")
}
override func viewWillAppear(_ animated: Bool) {
}
#IBAction func splitItemPressed(_ sender: UIButton) {
potentialBuyers.append("")
tableView.reloadData()
}
}
Here are the tableview datasource and the delete button delegate.
extension EntryAlertViewController: UITableViewDataSource, DeleteButtonDelegate {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return potentialBuyers.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "ReusableCell", for: indexPath) as! BuyerCell
cell.deleteButtonDelegate = self
cell.indexPath = indexPath
cell.nameField.text = cell.buyerName
if potentialBuyers.count == 1 {
cell.deleteButton.isHidden = true
} else {
cell.deleteButton.isHidden = false
}
return cell
}
func deletePressed(index: Int) {
potentialBuyers.remove(at: index)
tableView.reloadData()
}
}
And here is my BuyerCell class with the UITextFieldDelegate as an extension.
import UIKit
protocol DeleteButtonDelegate {
func deletePressed(index: Int)
}
class BuyerCell: UITableViewCell {
#IBOutlet weak var deleteButton: UIButton!
#IBOutlet weak var nameField: UITextField!
var deleteButtonDelegate: DeleteButtonDelegate!
var indexPath: IndexPath!
var buyerName: String?
override func awakeFromNib() {
super.awakeFromNib()
self.nameField.delegate = self
}
#IBAction func deletePressed(_ sender: UIButton) {
//print the indexPath.row that this was pressed for
print("delet pressed for \(indexPath.row)")
self.deleteButtonDelegate?.deletePressed(index: indexPath.row)
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
}
extension BuyerCell: UITextFieldDelegate {
func textFieldDidBeginEditing(_ textField: UITextField) {
print("textFieldDidBeginEditing")
buyerName = nameField.text
}
func textFieldDidEndEditing(_ textField: UITextField) {
print("textFieldDidEndEditing")
buyerName = nameField.text
}
}
Your problem is in this line
cell.nameField.text = cell.buyerName
Cells are reused from a reuse pool, so you can't rely on the cell holding any particular state or value.
Your buyer name needs to come from your data model array.
Something like
cell.nameField.text = self.potentialBuyers[indexPath.row]
Reloading the whole tableview is a bit excessive when you have only deleted a single row; Just delete the relevant row.
You can also clean up your delegation protocol so that there is no need for the cell to track its indexPath -
protocol DeleteButtonDelegate {
func deletePressed(in cell: UITableViewCell)
}
In your cell:
#IBAction func deletePressed(_ sender: UIButton) {
self.deleteButtonDelegate?.deletePressed(in: self)
}
In your view controller:
func deletePressed(in cell: UITableViewCell) {
guard let indexPath = tableView.indexPath(for: cell) else {
return
}
potentialBuyers.remove(at: indexPath.row)
tableView.deleteRows(at:[indexPath], with: .automatic)
}
There is a major issue in your code. You are not updating the data model so the changes in the cells are lost when the user scrolls.
Rather then quite objective-c-ish protocol/delegate in Swift callback closures are much more convenient and efficient. You can use one callback for both updating the model and deleting the cell.
Replace the BuyerCell cell with
class BuyerCell: UITableViewCell {
#IBOutlet weak var deleteButton: UIButton!
#IBOutlet weak var nameField: UITextField!
var callback : ((UITableViewCell, String?) -> Void)?
override func awakeFromNib() {
super.awakeFromNib()
self.nameField.delegate = self
}
#IBAction func deletePressed(_ sender: UIButton) {
callback?(self, nil)
}
}
extension BuyerCell: UITextFieldDelegate {
func textFieldDidBeginEditing(_ textField: UITextField) {
print("textFieldDidBeginEditing")
callback?(self, nameField.text)
}
func textFieldDidEndEditing(_ textField: UITextField) {
print("textFieldDidEndEditing")
callback?(self, nameField.text)
}
}
In the controller in cellForRow assign the callback and handle the actions. The actions work also reliably if cells are reordered, inserted or deleted.
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "ReusableCell", for: indexPath) as! BuyerCell
let buyerName = potentialBuyers[indexPath.row]
cell.nameField.text = buyerName
cell.callback = { [unowned self] cCell, cName in
let currentIndexPath = tableView.indexPath(for: cCell)!
if let name = cName {
self.potentialBuyers[currentIndexPath.row] = name
} else {
self.potentialBuyers.remove(at: currentIndexPath.row)
tableView.deleteRows(at: [currentIndexPath], with: .fade)
}
}
cell.deleteButton.isHidden = potentialBuyers.count == 1
return cell
}
I have a TableViewCell class like this:
class CampaignsTableViewCell: UITableViewCell {
#IBOutlet weak var activateButton: UIButton!
#IBOutlet weak var titleCampaignPlaceholder: UILabel!
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
setUpButton()
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
private func setUpButton(){
activateButton.backgroundColor = .clear
activateButton.layer.cornerRadius = 5
activateButton.layer.borderWidth = 1
activateButton.layer.borderColor = UIColor.blue.cgColor
}
}
And, in another class which is a ViewController I have my UITableView methods:
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let rowNumber = indexPath.row
let cellIdentifier = "CampaignTableViewCell"
guard let cell = tableView.dequeueReusableCell(withIdentifier: cellIdentifier, for: indexPath) as? CampaignsTableViewCell else {
fatalError("The dequeued cell is not an instance of TableViewCellController.")
}
cell.titleCampaignPlaceholder.text = campaignsArray[rowNumber].campaignName
return cell
}
I need to use my activateButton in my UITableView method in order to access to campaignsArray. I have another method which requieres values from that array, so I need that method is called every time activateButton is pressed from my UITableView.
Any idea ?
Thank you very much
What I like doing in those cases where you have a button inside your UITableViewCell is the following:
Give the cell a closure that is called when tapping on the button like so
class CampaignsTableViewCell: UITableViewCell {
... all your code....
// give your cell a closure that is called when the button is pressed
var onButtonPressed: ((_ sender: UIButton) -> ())?
#IBAction func buttonPressed(sender: UIButton) { // wire that one up in IB
onButtonPressed?(sender)
}
}
and then inside your TableViewController
let cell = tableView.dequeueReusableCell(withIdentifier: cellIdentifier, for: indexPath) as! CampaignsTableViewCell
cell.titleCampaignPlaceholder.text = campaignsArray[rowNumber].campaignName
cell.onButtonPressed = { [weak self] sender in
// Do your magic stuff here
}
return cell
Hope that helps
Your cell will get that event, not tableView. What you need to do is:
Create protocol inside your cell:
protocol CampaignsTableViewProtocol{
func actionButtonPressed(row: Int)
}
class CampaignsTableViewCell: UITableViewCell {
#IBOutlet weak var activateButton: UIButton!
#IBOutlet weak var titleCampaignPlaceholder: UILabel!
// keep info about row
var rowIndex: Int = -1
// create delegate that will let your tableView about action button in particular row
var delegate : CampaignsTableViewProtocol?
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
setUpButton()
self. activateButton.addTarget(self, action: #selector(self.activatePressed), for: UIControlEvents.touchDown)
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
func activatePressed(){
self.delegate?.actionButtonPressed(row :rowIndex)
}
private func setUpButton(){
activateButton.backgroundColor = .clear
activateButton.layer.cornerRadius = 5
activateButton.layer.borderWidth = 1
activateButton.layer.borderColor = UIColor.blue.cgColor
}
}
Your tableViewController needs to adopt this protocol:
class MyTableViewController: UITableViewDelegate, UITableViewDataSource, CampaignsTableViewProtocol {
// rest of the code
}
Also, you will need to implement delegate function in your tableViewController:
func actionButtonPressed(row: Int) {
// get campaign you need
let campaign = campaignsArray[row]
// rest of the code
}
That's weird: I just set up a new Single-View iOS Project and put a TableView into the Main.storyboard. In this TableView I put a TableViewCell and into this Cell, I put an UILabel and an UISwitch.
For this TableViewCell I created a CocoaTouchClass MyTableViewCell and set this for the TableViewCell's Class in Interfacebuilder.
I connected Outlets for the UILabel and UISwitch to MyTableViewCell, as well as an action for the switch.
Also I connected the TableView's dataSource and delegate to the ViewController.
So, as I think, basic stuff for setting up a table.
My ViewController looks like this:
class ViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
var tableData = [[String: Bool]]()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
for index in 1...40 {
self.tableData.append([String(index): index%2 == 0])
}
}
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return self.tableData.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "mycell", for: indexPath) as! MyTableViewCell
let object = tableData[indexPath.row].first!
cell.myLabel.text = object.key
cell.mySwitch.setOn(object.value, animated: false)
return cell
}
}
So, I populate the Table with some Rows of Data and switch every second UISwitch to on.
The MyTableViewCell-Class is nothing special as well:
class MyTableViewCell: UITableViewCell {
#IBOutlet weak var myLabel: UILabel!
#IBOutlet weak var mySwitch: UISwitch!
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
#IBAction func switched(_ sender: UISwitch) {
print("Switched: \(sender.isOn)")
}
}
Ok, fire up the iOS-Simulator and I see the Table as expected. 40 Table-Lines don't fit on one screen, so the TableView makes itself scrollable.
Now: when I change the state of one UISwitch, and drag the TableView so the changed UISwitch gets out of view and then drag the TableView so the changed UISwitch gets visible again, it is changed back to its initial state.
The Switch-event gets fired like it should.
So, what am I doing wrong? Am I missing something?
I recorded a 4-seconds-Screencast to demonstrate, what's going on:
http://b-bereich.de/download/swiftSwitch.mov
TableViewCells are reused.
That means you need to keep track of the data you are using to fill the content of the cells. If the cell content changes - such as when you tap a Switch in the cell - you need to update your datasource. When you scroll, and that row is displayed again, your data will know how to set the state of the Switch.
Here is a simple example:
//
// TableWithSwitchTableViewController.swift
// SWTemp2
//
// Created by Don Mag on 6/5/17.
// Copyright © 2017 DonMag. All rights reserved.
//
import UIKit
class MyTableViewCell: UITableViewCell {
#IBOutlet weak var myLabel: UILabel!
#IBOutlet weak var mySwitch: UISwitch!
var switchTapAction : ((Bool)->Void)?
#IBAction func switched(_ sender: UISwitch) {
print("Switched: \(sender.isOn)")
// send the Switch state in a "call back" to the view controller
switchTapAction?(sender.isOn)
}
}
// simple data object
class MyObject: NSObject {
var theTitle = ""
var theSwitchState = false
init(_ title: String) {
theTitle = title
}
}
class TableWithSwitchTableViewController: UITableViewController {
// array of MyObjects
var myData = [MyObject]()
override func viewDidLoad() {
super.viewDidLoad()
// just to make it a little easier to see the rows scroll
tableView.rowHeight = 60
// create 40 data objects for the table
for i in 1...40 {
let d = MyObject("Data Item: \(i)")
myData.append(d)
}
tableView.reloadData()
}
// MARK: - Table view data source
override func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return myData.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "SwitchCell", for: indexPath) as! MyTableViewCell
// Configure the cell...
let d = myData[indexPath.row]
cell.myLabel.text = d.theTitle
cell.mySwitch.isOn = d.theSwitchState
// set a "Callback Closure" in the cell
cell.switchTapAction = {
(isOn) in
// update our Data Array to the new state of the switch in the cell
self.myData[indexPath.row].theSwitchState = isOn
}
return cell
}
}
I think you need to have your IBAction change the Bool each time you flip the switch. Currently the switch changes the UI but not the underlying Bool so the cellForRowAt method uses the currently saved value when the cell scrolls back on screen.
Add function prepareForReuse() in your custom cell class and set switch state to off by default. -:
class MyTableViewCell: UITableViewCell {
#IBOutlet weak var myLabel: UILabel!
#IBOutlet weak var mySwitch: UISwitch!
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
#IBAction func switched(_ sender: UISwitch) {
print("Switched: \(sender.isOn)")
}
override func prepareForReuse(){
// SET SWITCH STATE OFF HERE
}
i have UITableView , with custom UITableViewCell have two uitextfiled
i want to get text of each uitextfiled as array
there is also button to add new cell in UITableView
show how can i deal with this
Edit
this is custom uitabelcell class
#IBOutlet weak var treatmentCount: UITextField!
#IBOutlet weak var treatmentText: UITextField!
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
}
override func setSelected(selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
and this UITabelView Controller
var tretments = [(name:String,count:String)](count: 15 , repeatedValue: (name: "" , count: ""))
var tretmentNames = ""
var tretmnetCounts = NSMutableDictionary()
var count = 5
#IBOutlet weak var orderTableView: UITableView!
#IBAction func addItem(sender: AnyObject) {
count += 1
save()
orderTableView.reloadData()
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = orderTableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as! OrderItemTableViewCell
cell.treatmentText.text = tretments[indexPath.row].name
cell.treatmentCount.text = tretments[indexPath.row].count
return cell
}
func save() {
for rowIndex in 0...self.orderTableView.numberOfRowsInSection(0) {
let indexPath : NSIndexPath = NSIndexPath(forItem: rowIndex, inSection: 0);
if (self.orderTableView.cellForRowAtIndexPath(indexPath) != nil) {
let cell = self.orderTableView.cellForRowAtIndexPath(indexPath) as! OrderItemTableViewCell
print(indexPath.row)
tretments.insert((name: cell.treatmentText.text!, count: cell.treatmentCount.text!),atIndex:indexPath.row)
print("Name:\(cell.treatmentText.text), Count: \(cell.treatmentCount.text)")
}
}
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return count
}
i need to get all user input in textfield and also skip other that user didn't input any text in textfield
the problem here in my code when user try to scroll on uitabelview
You could make an outlet collection and iterate over it to get each text field value. If you want to preserve order use the tag property.
I have a UITableView (with a Custom class called CellModelAllNames for each row). Each Row has a Label and a button.
My question is: When btn_addRecording (i.e. the '+' button is clicked on any/each of the rows, how do I get the lbl_name.text, the label name shown, and show a pop up in the ViewController itself. I want to get additional information in the pop up and then save all the info (including the lbl_name to a database).
CellModelAllNames for each row layout:
import UIKit
class CellModelAllNames: UITableViewCell {
#IBOutlet weak var lbl_name: UILabel!
#IBOutlet weak var btn_addRecording: UIButton!
#IBAction func btnAction_addRecording(sender: AnyObject) {
println("clicked on button in UITableViewCell")
}
override func awakeFromNib() {
super.awakeFromNib()
}
override func setSelected(selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
}
func setCell(setBabyName: String) {
self.lbl_name.text = setBabyName
}
}
Here's the code of my ViewController:
import UIKit
class SecondViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
#IBOutlet weak var tbl_allNames: UITableView!
var arrayOfNames: [Name] = [Name]()
override func viewDidLoad() {
super.viewDidLoad()
self.tbl_allNames.delegate = self
self.tbl_allNames.dataSource = self
self.tbl_allNames.scrollEnabled = true
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
var cell:CellModelAllNames = self.tbl_allNames.dequeueReusableCellWithIdentifier("CellModelAllNames") as! CellModelAllNames
let name = arrayOfNames[indexPath.row]
cell.setCell(name.name)
println("in tableView, cellforRowatIndex, returning new cells")
return cell
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return arrayOfNames.count
}
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
}
}
You can use standard UIKit methods to get the cell and its data:
func tappedButton(sender : UIButton) {
let point = sender.convertPoint(CGPointZero, toView: self.tableView)
let indexPath = self.tableView.indexPathForRowAtPoint(point)!
let name = arrayOfNames[indexPath.row]
// do something with name
}
You can add button action in your ViewController
1) In your function cellForRowAtIndexPath assign button's tag as index (ie. indexPath.row)
cell.btn_addRecording.tag = indexPath.row
2) Add target and action for your button :
cell.btn_addRecording.addTarget(self, action: "buttonPressed:", forControlEvents: .TouchUpInside)
3) Add action in ViewControler (ie. save info in database)
func buttonPressed(button: UIButton!)
{
// Add your code here
let name = arrayOfNames[button.tag]
}