override func tableView (_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {let cell = tableView.dequeueReusableCell (withIdentifier: "cell", for: indexPath)
let customerNameLabel = UILabel()
customerNameLabel.frame = CGRect (x: 10, y: 5, width: 150, height: 40)
customerNameLabel.textColor = .black
customerNameLabel.text = "Customer Name\ (indexPath.row)"
cell.contentView.addSubview(customerNameLabel)
return cell
}
While trying to add label to cell it is adding number of times even while scrolling the tableView but I need to add label only once and reuse it
You need to create a custom UITableViewCell and add your label to it.
Because in the code you provided you will be adding a UILabel() to the cell every time the cell is reused.
You need create a subclass for UITableViewCell
If you load your cell from xib file, override awakeFromNib and add your label to cell inside awakeFromNib method.
If you create your cell programmatically, override init(style: UITableViewStyle) and add your label to cell inside init(style: UITableViewStyle) method.
Due to the reusable behavior of UITableViewCell, the label is added multiple time in a single cell because the cell is being reused if you want to add a single label on the cell you have to check first if it already added.
What we are frequently used:
1) We make the .xib of a cell and reuse it:
2) We make the cell in the storyboard and give the specific identifier to cell and reuse it:
3) You can check the label is already added:
var customerNameLabel:UILable? = nil
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) {
if customerNameLabel == nil {
customerNameLabel = UILabel()
customerNameLabel.frame = CGRect(x: 10, y: 5, width: 150, height: 40)
customerNameLabel.textColor = .black
cell.contentView.addSubview(customerNameLabel)
}
customerNameLabel.text = "Customer Name\(indexPath.row)"
return cell
}
Several simple steps:
Subclass UITableViewCell.
Add the label to contentView inside awakeFromNib (override this method) if you load from nib OR init(style:reuseIdentifier:) (override this method) if you generate the cell programmatically. Alternatively you can set cell's layout in Storyboard of nib itself.
In tableView:cellForRow set the label's text to whatever you want.
That is Because TableView will call the cellForRowAt everytime you scroll or reload the tableView.
Either you subclass UITableViewCell and add a label there or you have to remove the label every time before adding it.
Related
I am creating an app with UITableViewCells that expand when selected. However, when the cell expands, the title (and subtitle) are moving downwards to stay centered vertically in the cell. I'd like them to stay where they were originally but can't figure out how to do it.
I have tried setting the frame manually with cell.textLabel?.frame = myRect, but this does nothing. I am unable to find any constraints, as print(cell.textLabel?.constraints) returns optional([]).
Here are my normal cells and my expanded cells.
My code for creating the cells:
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
var cell = tableView.dequeueReusableCell(withIdentifier: "reuseIdentifier")
if cell == nil {
cell = UITableViewCell(style: .value1, reuseIdentifier: "reuseIdentifier")
}
cell!.textLabel?.text = content[indexPath.row]
cell!.clipsToBounds = true
cell!.selectionStyle = .none
cell!.detailTextLabel?.text = detailContent[indexPath.row]
return cell!
}
Any help would be greatly appreciated.
You are using a standardized cell, the title and detail are fixed, i think you need make a custom cell for your project
Look this project I make a simple test with customized cell
https://github.com/TexugoProgramador/Teste-Celula-Customizada
How can I embed a UISwitch programmatically in a tableView cell in Swift?
I'm doing it like that
let shareLocationSwitch = UISwitch()
cell.accessoryView = shareLocationSwitch
Here is way you can embed a UISwitch on a UITableView cell.
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
var cell = tableView.dequeueReusableCell(withIdentifier: "yourcellIdentifire", for: indexPath) as! YourCellClass
//here is programatically switch make to the table view
let switchView = UISwitch(frame: .zero)
switchView.setOn(false, animated: true)
switchView.tag = indexPath.row // for detect which row switch Changed
switchView.addTarget(self, action: #selector(self.switchChanged(_:)), for: .valueChanged)
cell.accessoryView = switchView
return cell
}
here is switch call beck method
func switchChanged(_ sender : UISwitch!){
print("table row switch Changed \(sender.tag)")
print("The switch is \(sender.isOn ? "ON" : "OFF")")
}
#LeoDabus Great! explanation.
Note: if your tableview may have more than one section then You should create a CustomCell subclassing UITableViewCell and configure your accessoryView inside UITableViewCell awakeFromNib method instead of table view cellForRowAt method. When dequeuing the reusable cell cast it to your CustomCell Here is sample from #LeoDabus
if you update the array with 3 elements and refreshing the table using self.tableView.reloadData() (for example after 2 second) you can see that with Xcode13 the switch values will be swapped and the example doesn't work. I have similar issue with my App when Xcode has been released to 13. try this: https://drive.google.com/file/d/1_1HuI_JFIYusNmsdyekGBWXsGznneiQ7/view?usp=sharing
I have gotten to the point where I have a selectable list of options, which are all loaded into the same .xib files. I am trying to make it so upon the click on a cell a different .xib file is populated below, and all of the other cells shift down. However, I am unsure of how to have 2 different xib's as TableViewCells in swift.
There's two ways I can think of to accomplish what you are trying to do:
Single xib file: You should use a single xib file that hides the lower section that contains the options until the cell is tapped. When tapped, a property on the UITableCell class could be set, e.g. isExpanded. When isExpanded is set, your cell could unhide the options (by changing constraints).
Multiple xibs: When tapped, you could insert a new item into your datasource. In your cellForRow, you could check for some identifier and load either the regular cell or the options cell using something like this:
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
if indexPath.row == optionsRow {
let cell = tableView.dequeueReusableCell(withIdentifier: OptionsCellIdentifier, for: indexPath) as! OptionsCell
//Configure cell here
return cell
} else {
let cell = tableView.dequeueReusableCell(withIdentifier: NormalCellIdentifier, for: indexPath) as! NormalCell
//Configure cell here
return cell
}
}
When i clicked the subview,it didn't trigger subview's action. But i have selected whole cell. How to fix it?
Here is my code.
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("idcell", forIndexPath: indexPath) as UITableViewCell
let lblTitle : UILabel = cell.contentView.viewWithTag(101) as! UILabel
lblTitle.text = (deptId[indexPath.row] as? String)! + " " + (deptDesc[indexPath.row] as? String)!
var height:CGFloat = 40
if(indexPath.row == departmentSelectedRow){
for i in 0...deptProfile.count-1{
let label = UILabel(frame: CGRectMake(0,height,400,30))
label.targetForAction("sadasdd", withSender: nil)
height = height+40
label.text = ("ewrewrewre")
label.backgroundColor = UIColor.redColor()
cell.addSubview(label)
}
}
return cell
}
If you want to interact with something inside a cell (rather than select the whole cell) then you should use a button or a gesture recogniser. These are properly interactive elements that you can add a target and action to.
You should also change how you're using cells, specifically:
Use custom cell classes, so you can directly reference the cell elements instead of using viewWithTag which is bad practice
Use multiple different cell classes (and thus identifiers) so you can use actually different cells for selected and unselected rows
Don't create and add subviews on the fly, this is what the different cell classes are for
I have some text which goes into UIlabels I have created inside a table view cell. When these table view cells become updated the text overlaps itself, almost like the previous text what was there has not been removed, like so:
code:
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Cell",forIndexPath: indexPath) as! UITableViewCell
var nameLabel = UILabel(frame: CGRectMake(cell.frame.size.width * 0.040, cell.frame.size.height * 0.22, cell.frame.size.width * 0.735, cell.frame.size.height * 0.312))
var userAtIndexPath = finalMatchesBlurUser[indexPath.row]
nameLabel.text = userAtIndexPath.username.uppercaseString
cell.addSubview(nameLabel)
}
The finalMatchesBlurUser is a PFUser fetched from Parses database that will be changing, when this change is what causes the names to overlap.
Can anyone point out why this is happening?
Everytime you update the tableview, it checks the queue to see if it can reuse a cell instead of initializing a new one. In this case, when it updates, it has cells in the queue so you're adding a new label subview everytime the table updates which is causing this effect. In this case, you should only add the label subview if it doesn't exist already. Otherwise, just update the text of that subview.
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Cell",forIndexPath: indexPath) as! UITableViewCell
if let nameLabel = cell.viewWithTag(100) as? UILabel{
var userAtIndexPath = finalMatchesBlurUser[indexPath.row]
nameLabel.text = userAtIndexPath.username.uppercaseString
}
else{
nameLabel = UILabel(frame: CGRectMake(cell.frame.size.width * 0.040, cell.frame.size.height * 0.22, cell.frame.size.width * 0.735, cell.frame.size.height * 0.312))
nameLabel.tag = 100;
var userAtIndexPath = finalMatchesBlurUser[indexPath.row]
nameLabel.text = userAtIndexPath.username.uppercaseString
cell.addSubview(nameLabel)
}
return cell;
}
the UILabel is created every time even when the cell is reused.
A solution is to create the UILabel in Interface Builder and assign a tag (e.g. 100).
Then use this code
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Cell",forIndexPath: indexPath) as! UITableViewCell
let nameLabel = cell.viewWithTag(100) as! UILabel
let userAtIndexPath = finalMatchesBlurUser[indexPath.row]
nameLabel.text = userAtIndexPath.username.uppercaseString
}