I have created a custom UIButton class:
class MyButton: UIButton {
}
Then I added a UIButton to my storyboard and changed its class to MyButton.
Now when I right-click-drag the button to code, I am able to add Outlet but not Action. "Sent Events" section also disappears in property inspector. What could I be missing?
The only trick I've discovered until now is to change the button class back to UIButton, add the requested actions and then change back the class to MyButton :/
The bug is still there.
I was able to fix this by saving and restarting Xcode.
I know this problem is almost two years old, but I ran into it today. Restarting Xcode did not help. I noticed in some older .xib's, that there were some linked Sent Events, but all the rest of the touchDown etc. options were missing. However, after I hovered over the source on one of the remaining Sent Events, Xcode popped up a 'UIButton' is no longer a valid event source message. In this link, someone discovered that that problem is linked to an extension of UIButton. Sure enough, I refactored the UIButton extension we had to UIControl and all the Sent Event options returned.
Based on the OP's issue and what I read today, Apple is trying to tell us to leave their buttons alone. :)
you can use this code easy as pie
override func awakeFromNib() {
self.addTarget(self, action: "buttonClicked:", forControlEvents: UIControlEvents.TouchDown)
self.addTarget(self, action: "buttonUnClicked:", forControlEvents: UIControlEvents.TouchUpInside)
self.addTarget(self, action: "buttonUnClicked:", forControlEvents: UIControlEvents.TouchUpOutside)
}
func buttonClicked(sender: UIButton){
self.backgroundColor = UIColor.redColor()
}
func buttonUnClicked(sender: UIButton){
self.backgroundColor = UIColor.blackColor()
}
Related
My senior was reviewing my code and he found that I have used UIButton addTarget method like this
override func viewDidLoad() {
super.viewDidLoad()
self.btnAccount.addTarget(self, action: #selector(Accounts(_:)), for: .touchUpInside)
}
Now he is saying that you should not use addTarget in viewDidLoad it will take time(kind of memory management thing I didn't get it) to load view controller but I didn't find it relevant
that's why I am asking this question did I made some mistake by doing this should I always make actions
I didn't hear of that and even if it is true, you should never try to do premature optimization on your app. UIButton is a UIControl object, which follows an event-listener pattern, which is often implemented with a hashmap (NSDictionary in Objective-C) of targets ('aka' Listeners or Observers) and it is not very time-consuming operation.
I personally prefer to setup all UI component right at the beginning:
lazy var btnAccount: UIButton = {
let btn = UIButton
// setup button's appearance
btn.addTarget(self, action: #selector(Accounts(_:)), for: .touchUpInside)
return btn
}()
P.S. Please ask him about the source of the fact and let me know.
I am trying to make my button, when tapped, to push to a new View Controller. I've tried many different ways but it won't trigger the function that I have it linked to. I also checked the 3D stack view of my layers and the button is on top and clickable, even when I check the background color, it's not being covered by anything else.
Does anyone have any ideas to what I am doing wrong?
For now I am trying to make the button print out the sentence in the console, however whenever I press it, the string doesn't pop up, so I haven't bothered to connect it to the view controller yet.
Also, I am coding this app without storyboards.
Here is my code below.
It is under the MainPageCell class declared as a UICollectionViewCell
private let playButton: UIButton = {
let button = UIButton()
button.setTitle("", for: .normal)
button.backgroundColor = .clear
button.translatesAutoresizingMaskIntoConstraints = false
button.addTarget(self, action: #selector(MainPageCell.buttonTapped), for: .touchUpInside)
return button
}()
#objc func buttonTapped() {
print("I PRESSED THE BUTTON")
}
This line is wrong:
button.addTarget(self, action: #selector(MainPageCell.buttonTapped), for: .touchUpInside)
You cannot assign self as the action target in a property declaration initializer, because the instance designated by self does not exist yet. There is no error or warning (I regard that as a bug), but the action method is never called.
Move that assignment elsewhere and rewrite it, like this:
self.playButton.addTarget(self, action: #selector(MainPageCell.buttonTapped), for: .touchUpInside)
Maybe try defining your button action under the UIView Class, I've had a problem like that before, only worked when i linked it to the View Class, Good luck
and thanks in advance for taking the time to help.
Inside my CellForRowAtIndexPath, I have the following line:
cell.timeView.addTarget(self, action: "ButtonDidPress:", forControlEvents: UIControlEvents.TouchUpInside)
and my selector function is:
func ButtonDidPress (sender: DesignableView!){
let view:DesignableView = sender
cell.timeView.shadowColor = UIColor.yellowColor()
table.reloadData()
}
and the error i get is:
unrecognized selector sent to instance
I'm thinking that perhaps one can't send a View as a selector (am I using the correct terminology?), but how else can I target that particular view in that cell?
UPDATE:
I also tried using gestureRecognizer instead:
var tap = UIGestureRecognizer(target: self, action: Selector( "viewDidTap:"))
cell.timeView.addGestureRecognizer(tap)
and
func viewDidTap (sender: DesignableView!){
but I got the same error here.
Thanks!
There's a couple of strange things happening in your code. It seems you want to change the shadowColor property of timeView when a user touch it, right?
Two possible solutions are:
(This one is IMO the better one) Change DesignableView to inherit from UIButton. Then you can set:
timeView.addTarget(self, action: "ButtonDidPress:", forControlEvents: .TouchUpInside). Make sure you set it just once for each cell. Otherwise you will get multiple calls on one tap.
Use UITapGestureRecognizer, but you should put it in your UITableViewCell subclass, not to the view controller. Also, the sender in viewDidTap is not the view itself, but the recognizer. So the method will go like this:
func viewDidTap(sender: UITapGestureRecognizer) {
let location = sender.locationInView(sender.view)
if timeView.hitTest(location, withEvent: nil) == timeView {
timeView.shadowColor = UIColor.yellowColor()
// table.reloadData() - you don't need to reload the table
}
}
I have two classes UIVIewController and UITableviewcell. In UITableviewcell, i have a button and the button action should be in UIViewController. How can i pass a class and set delegate in button action.
i tried this code,
//UIVIewController
cell.createButton(self)
func buttonClick(object:AnyObject){
println("Button Clicked")
}
//UITableViewCell
func createButton(delegate:AnyObject){
//button created.
button.addTarget(delegate, action: "buttonClick:", forControlEvents: UIControlEvents.TouchUpInside)
}
But the above code is not working. 'buttonClick' function is not calling
I had the same problem a while ago, trying to put self in place of "delegated".
otherwise try to take a look at this question:
link
I hope to be helped.
I'm writing some unit tests and, because of the nature of this particular app, it's important that I get as high up the UI chain as possible. So, what I'd like to do is programmatically trigger a button-press, as if the user had pressed the button in the GUI.
(Yes, yes -- I could just call the IBAction selector but, again, the nature of this particular app makes it important that I fake the actual button press, such that the IBAction be called from the button, itself.)
What's the preferred method of doing this?
It turns out that
[buttonObj sendActionsForControlEvents:UIControlEventTouchUpInside];
got me exactly what I needed, in this case.
EDIT: Don't forget to do this in the main thread, to get results similar to a user-press.
For Swift 3:
buttonObj.sendActions(for: .touchUpInside)
An update to this answer for Swift
buttonObj.sendActionsForControlEvents(.TouchUpInside)
EDIT: Updated for Swift 3
buttonObj.sendActions(for: .touchUpInside)
Swift 3:
self.btn.sendActions(for: .touchUpInside)
If you want to do this kind of testing, you’ll love the UI Automation support in iOS 4. You can write JavaScript to simulate button presses, etc. fairly easily, though the documentation (especially the getting-started part) is a bit sparse.
In this case, UIButton is derived from UIControl. This works for object derived from UIControl.
I wanted to reuse "UIBarButtonItem" action on specific use case. Here, UIBarButtonItem doesn't offer method sendActionsForControlEvents:
But luckily, UIBarButtonItem has properties for target & action.
if(notHappy){
SEL exit = self.navigationItem.rightBarButtonItem.action;
id world = self.navigationItem.rightBarButtonItem.target;
[world performSelector:exit];
}
Here, rightBarButtonItem is of type UIBarButtonItem.
For Xamarin iOS
btnObj.SendActionForControlEvents(UIControlEvent.TouchUpInside);
Reference
Swift 5:
class ViewController: UIViewController {
#IBOutlet weak var theTextfield: UITextField!
#IBOutlet weak var someButton: UIButton!
override func viewDidLoad() {
super.viewDidLoad()
theTextfield.text = "Pwd"
someButton.sendActions(for: .touchUpInside)
}
#IBAction func someButtonTap(_ sender: UIButton) {
print("button tapped")
}
}
It's handy for people who write Unit Tests without UI Tests ;-)
Swift 5 way to solve it for UIBarButtonItem, which does not have sendAction method like UIButton etc.
extension UIBarButtonItem {
func sendAction() {
guard let myTarget = target else { return }
guard let myAction = action else { return }
let control: UIControl = UIControl()
control.sendAction(myAction, to: myTarget, for: nil)
}
}
And now you can simply:
let action = UIBarButtonItem(title: "title", style: .done, target: self, action: #selector(doSomething))
action.sendAction()
Swift 4:
self .yourButton(self)