I'm using a table view with custom cell. In this custom cell I got a like button.
when I tap this button I want this one to get colored. I figure how to color this button but I need to do reload data for displaying it with color. But when I call "table.reloadData()" there is a little scroll view stretch automatically.
There is a way to display changes without reloadData() or to disable scrollView stretching?
Have you tried reloading just the row that you have clicked on?
tableView.reloadRowsAtIndexPaths([indexPath], withRowAnimation: UITableViewRowAnimation.Top
For some things, though, you shouldn't have to reload at all. If all you want is to change the background colour of the cell, you can do it like this. I now notice that you're working in Objective-C and my example is Swift - hopefully it's still clear enough :-)
First define a custom cell - mine is a simple one with just a label and a button, you will already have something similar. I'm not sure if you need to change the colour of the cell, or the button, so I have done both
import UIKit
class myCell: UITableViewCell
{
#IBOutlet weak var labelTitle: UILabel!
#IBOutlet weak var cmdButton: UIButton!
#IBAction func cmdButtonClicked(sender: AnyObject)
{
self.backgroundColor = UIColor.redColor()
cmdButton.backgroundColor = UIColor.blueColor()
print("click \(sender.tag)")
}
}
If you do need to keep a track of which button has been clicked, you will need to set the tag in cellForRowAtIndexPath - but you may not even need this
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell
{
var cell:myCell = tableView.dequeueReusableCellWithIdentifier("Cell") as! myCell
cell.labelTitle.text = data[indexPath.row]
cell.cmdButton.tag = indexPath.row
return cell
}
Related
Problem I want to allow users to hit 'swap' in a table cell and then find a different Realm object to populate the 2 text labels (for exercise name and number of reps) in the cell with the values from the new object.
Research There's quite a bit (admittedly old) on 'moving rows' (e.g. here How to swap two custom cells with one another in tableview?) and also here (UITableView swap cells) and then there's obviously a lot on reloading data in itself but I can't find anything on this use case.
What have I tried my code below works fine for retrieving a new object. i.e. there's some data in the cell, then when you hit the 'swapButton' it goes grabs another one ready to put in the tableView. I know how to reload data generally but not within one particular cell in situ (the cell that the particular swap button belongs to... each cell has a 'swap button').
I'm guessing I need to somehow find the indexRow of the 'swapButton' and then access the cell properties of that particular cell but not sure where to start (I've played around with quite a few different variants but I'm just guessing so it's not working!)
class WorkoutCell : UITableViewCell {
#IBOutlet weak var exerciseName: UILabel!
#IBOutlet weak var repsNumber: UILabel!
#IBAction func swapButtonPressed(_ sender: Any) {
swapExercise()
}
func swapExercise() {
let realmExercisePool = realm.objects(ExerciseGeneratorObject.self)
func generateExercise() -> WorkoutExercise {
let index = Int(arc4random_uniform(UInt32(realmExercisePool.count)))
return realmExercisePool[index].generateExercise()
}
}
//do something here like cell.workoutName
//= swapExercise[indexRow].generateExercise().name???
}
Hold your objects somewhere in a VC that shows UITableView. Then add the VC as the target to swap button. Implement swapping objects on button press and reload data of table view after.
The whole idea is to move logic to view controller, not in separate cell.
There are 2 ways.
1. Adding VS as button action target.
public func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = ... // get cell and configure it
cell.swapBtn.addTarget(self, action: #selector(swapTapped(_:)), for: .touchUpInside)
return cell
}
func swapTapped(_ button: UIButton) {
let buttonPosition = button.convertPoint(CGPointZero, toView: self.tableView)
let indexPath = self.tableView.indexPathForRowAtPoint(buttonPosition)!
// find object at that index path
// swap it with another
self.tableView.reloadData()
}
Make VC to be delegate of cell. More code. Here you create protocol in cell and add delegate variable. Then when you create cell you assign to VC as delegate for cell:
public func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = ... // get cell and configure it
cell.delegate = self
return cell
}
func swapTappedForCell(_ cell: SwapCell) {
// the same logic for swapping
}
Solution from OP I adapted the code here How to access the content of a custom cell in swift using button tag?
Using delegates and protocols is the most sustainable way to achieve this I think.
I hope this helps others with the same problem!
I have a button in a cell as a toggle to check in members in a club. When I check in a member, I need the button's state to stay ON after scrolling, but it turns back off. Here is the cellForRow method:
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = self.membersTableVw.dequeueReusableCell(withIdentifier: "CellMembersForCoach", for: indexPath) as! CellMembersForCoach
let member = members[indexPath.row]
cell.setMember(member)
cell.cellController = self
return cell
}
Here is the portion in the custom cell class where I toggle the button
#IBOutlet weak var checkBtn: UIButton!
#IBAction func setAttendance(_ sender: Any){
// toggle state
checkBtn.isSelected = !checkBtn.isSelected
}
The toggling works but after scrolling the table, the button state changes back to original. Any suggestion is appreciated.
This happens because you are reusing the cells.
You need to keep track of which cells have been selected. Perhaps in your member's class. Then when you are in your cellForRowAt you should check if this cell has been selected before and set the correct state for your button.
This is because of tableview is reusing your cell. so you have to maintain button as per tableView data source.
Shamas highlighted a correct way to do it, so I'll share my whole solution.
I created a singleton class to store an array of checked cells:
class Utility {
// Singleton
private static let _instance = Utility()
static var Instance: Utility{
return _instance
}
var checkedCells = [Int]()
In the custom cell class I have action method wired to the check button to add and remove checked cells:
#IBOutlet weak var checkBtn: UIButton!
#IBAction func setAttendance(_ sender: Any){
// Get cell index
let indexPath :NSIndexPath = (self.superview! as! UITableView).indexPath(for: self)! as NSIndexPath
if !checkBtn.isSelected{
Utility.Instance.checkedCells.append(indexPath.row)
}else{
// remove unchecked cell from list
if let index = Utility.Instance.checkedCells.index(of: indexPath.row){
Utility.Instance.checkedCells.remove(at: index)
}
}
// toggle state
checkBtn.isSelected = !checkBtn.isSelected
}
In the cellForRowAt method in the view controller I check if the cell row is in the array and decide if the toggle button should be checked:
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = self.membersTableVw.dequeueReusableCell(withIdentifier: "CellMembersForCoach", for: indexPath) as! CellMembersForCoach
if Utility.Instance.checkedCells.contains(indexPath.row){
cell.checkBtn.isSelected = true
}
return cell
}
The problem is here:
checkBtn.isSelected = !checkBtn.isSelected
This code will reflect the button selection state every time the cell is configured when the delegate cellForRowAt invokes. So if you selected it before, now it turns to not-selected.
Since the tableView is reusing cells you code is not going to work.
You have to keep track of each button when selected and set it again when tableview is reusing cells when you scroll.
Solution : You can take an array(contains bool) which is size of your tableview data.
So you have to set state of button using array and update array when selected or deselected.
I'm doing todolist app and I need action for button, which on tapped will do change image in a cell which I tapped on it. Cell retrieves data from Firebase to UITableView. I used button and image outlets and both reported this error:
The button from the TaskViewController to the UIButton is invalid. Outlets cannot be connected to repeating content.
I have this code for retrieves data to cell:
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "TasksCell", for: indexPath) as! TasksCell
let arrayTasks = tasks[indexPath.row]
cell.taskName.text = arrayTasks.content
return cell
}
and I have this in Storyboard
object left of the label is button.
The button picture is set in storyboard.
I don't know how to do it, because I don't have much experience. Please help me.
Try:
Open the Identity Inspector.
Click the prototype cell.
Set the Class to TasksCell (in my example, it is WorkTableViewCell).
Click in the Module field, empty it, and press enter. It should change to Current - project_name_here (for example, Current - Artistry.
Here's a screenshot of what it should look like. Check it to make sure you selected the right items in the right order:
Then, delete the old outlet(s) to the cell (button, label, everything) from the Connections Inspector. Do that step while selecting the cell, and then while selecting the view controller (but while selecting the view controller, only delete the outlet to the "completed" button).
And finally, re-add them by opening the code (in a new window) for your TasksCell class, not the TaskViewController class (probably in TasksCell.swift), and directly under the line:
class TasksCell: UITableViewCell {
(or similar), hold control and drag the button, label, etc. as shown:
And finally, finish creating the new outlets only from the label, button, etc. to the TasksCell class as mentioned earlier (see note below before pressing "connect"):
Change the Name as necessary. It could be something like taskName for the label, or completedButton for the button. Do not change the Type or any other fields. Press "connect", and the code from your question should work.
In your TasksCell class, connect the button to the cell, and you can access it easier (yeah agree to #ingraham, you can't connect it to your view controller):
class TasksCell: UITableViewCell {
#IBOutlet weak var buttonCheckbox: UIButton!
#IBOutlet weak var taskName: UILabel!
#IBOutlet weak var updatedDate: UILabel!
}
You can use image view for button. Also you can use this method for changing image
override func tableView(_ tableView: UITableView, didSelec tRowAt indexPath: IndexPath) {}
Edit:
I made a table view cell class:
class TableViewCell: UITableViewCell {
#IBAction func bAction(_ sender: Any) {
button.titleLabel?.text = "asdaf"
}
#IBOutlet weak var button: UIButton!
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
}
}
then I edit tableView function:
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell: TableViewCell! = tableView.dequeueReusableCell(withIdentifier: "reuseIdentifier", for: indexPath) as? TableViewCell
cell.textLabel?.text = "abc"
// Configure the cell...
cell.bAction(Any.self)
return cell
}
Currently I have a few of custom cell's prototypes created in Storyboard with text fields embedded in them. To access these text fields, I use nameTextField = cell.viewWithTag:(1) in cellForRowAtIndexPath:. But viewDidLoad: and viewWillAppear: methods get called before cellForRowAtIndexPath, so at that time nameTextField is nil. To populate text fields when table view shows on screen, I use viewDidAppear:, but it results in a noticeable delay. Also, when I scroll table view up and down, cellForRowAtIndexPath: gets called again and again, resetting already entered data in text fields.
Are there more efficient ways to populate text fields embedded in custom cells' prototypes with data just before the view shows up, and to prevent resetting of entered data in each cellForRowAtIndexPath: call?
I guess you're creating profile screen (or something with many textField to get input data from user). Am I right?
If I'm right, you can use a static tableView (when you have a few textFields)
Hope this can help.
I'm not sure I understand completely what you're trying to do, but cells are normally configured in the cellForRowAtIndexPath: method, not in viewDidLoad. You can also try connecting the textfield to an outlet on your custom cell class. Then you can do:
// in view controller
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath)
as! CustomCell
let object = myDataSource[indexPath.row]
cell.textField.text = object.description
cell.shouldBecomeFirstResponder = indexPath.row == 0
return cell
}
// then in the cell
class CustomCell: UITableViewCell {
#IBOutlet weak var textField: UITextField!
var shouldBecomeFirstResponder: Bool = false
override func awakeFromNib() {
if shouldBecomeFirstResponder {
textField.becomeFirstResponder()
}
}
}
Then when users input text into the textfield, it would make sense to update your data source.
In viewDidLoad try to run something like self.tableView.reloadData before you do this line "nameTextField = cell.viewWithTag:(1)".
I have an uitableview with a custom cell which gets data from the array.
Custom cell has an uilabel and an uibutton (which is not visible until the uilabel text or the array object which loads for the text - is nil).
On launch everything is fine. When i press the uibutton the array is being appended, the new cells are being inserted below the cell.
But when i scroll - all of a sudden the uibutton appears on other cells where this conditional uilabel text isEmpty is not implied.
Here is how the whole process looks like
Here is my code for cellForRowAtIndexPath
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
var cell:TblCell = self.tableView.dequeueReusableCellWithIdentifier("cell") as! TblCell
cell.lblCarName.text = someTagsArray[indexPath.row]
if let text = cell.lblCarName.text where text.isEmpty {
cell.act1.hidden = false
} else {
println("Failed")
}
cell.act1.setTitle(answersdict[answersdict.endIndex - 2], forState:UIControlState.Normal)
cell.act2.setTitle(answersdict.last, forState:UIControlState.Normal)
return cell
}
So my general question is how do i stop the reuse of those custom cells?
As far as i'm aware there is no direct way of doing this on reusablecellswithidentifier in swift, but maybe there are some workarounds on that issue?
When a cell is reused, it still has the old values from its previous use.
You have to prepare it for reuse by resetting that flag which showed your hidden control.
You can do this either in tableView:cellForRowAtIndexPath: or the cell's prepareForReuse method.
Update:
Here's an example you can add for TblCell:
override func prepareForReuse()
{
super.prepareForReuse()
// Reset the cell for new row's data
self.act1.hidden = true
}