I used Xcode9 Beta6 to build the project, the action was called correctly on iOS10 device, however it is not work on iOS11 device.
In My project, there are some viewControllers have a UIToolBar on the top, and the toolBar contains some UIBarButtonItems.
There is one this kind of viewController, whose UIBarButtonItem action is not called when I tap the UIBarButtonItem. I can see the tapping animation (the icon become dim first and back to normal after finger released)
At the end of viewDidLoad, I print the info of toolbar.items to indicate that target action are set properly.
Debug Output
In my case I was setting up the button and instantiating it as a property of the vc
class myVC: UIViewController {
let closeBarButtonItem = UIBarButtonItem(image: image, style: .plain, target: self, action: #selector(close(_:)))
}
If I moved this to ViewDidLoad it resolved the problem
class myVC: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let closeBarButtonItem = UIBarButtonItem(image: image, style: .plain, target: self, action: #selector(close(_:)))
}
}
I solved this problem by removing a current gesture recognizer from my view and adding a new one. Than I opened the connections inspector of my view and add gestureRecognizer connection to my gesture recognizer.
Apple has confirmed this bug.
My temporary solution is changing the gesture recognizer area by removing the overlap area, so that the tap gesture won't block the tap event on UIBarButtonItem.
It is happening only for iOS 11 and when custom UIView used for rightBarButtonItem (or left also). If you are using UIBarButtonItem then it will work fine.
There is 0 width of this custom bar item, so we need to set it to something.
In viewDidLoad of this controller you can add code, you can replace 100 to something what will work for you:
if let view = self.navigationItem.rightBarButtonItem?.customView {
view.widthAnchor.constraint(equalToConstant: 100).isActive = true
}
At least as an easy temporary solution it is fine.
In my case the problem was a gestureRecognizer added to the whole main view (in order to close the keyboard) like this:
UITapGestureRecognizer *gesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(closeKeyboard)];
[self.view addGestureRecognizer:gesture];
That gesture recognizer overrides the tap on the UIBarButtonItem, thus I solved by creating a new subview placed immediately below the navigation bar and assigning the gesture recognizer to that view and not to the whole main view.
Mark the method you are targeting at with #objc.
Related
I've got buttons on my view that are draggable using touches began/moved/ended.
I want to add a tapped and doubletapped actions for my buttons. Once I switch my button's class to UIButton the action I've created works, but once I change it back to DraggableView the actions stop being called because I guess touchesBegan overrides any other touches on the view.
Is there a good way to do this?
First of all you have to implement UITapGestureRecogizer delegate in your class and add following line of code.
let tap = UITapGestureRecognizer(target: self, action: "handleTap:")
tap.delegate = self
tap.numberOfTapsRequired = 1
yourButton.addGestureRecognizer(tap)
Hope this helps.
I have custom UIView that is being displayed in controller's view. I need to display a view controller modally when something in that custom view is tapped. What is the most efficient way to notify the view controller (if it exists) about the touch from the custom view's touchesBegan()?
You can use UITapGestureRecognizer. Declare UITapGestureRecognizer like this and add gesture recognizer to your custom view
let tapGesture = UITapGestureRecognizer(target: self, action: #selector(ViewController.tapOnCustomView(_:)))
customView.addGestureRecognizer(tapGesture)
Now receive the tap
func tapOnCustomView(tap:UITapGestureRecognizer){
// present your targeted view controller modally
}
NB: UITapGestureRecognizer allocation syntax vary with Swift version. This one is for Swift 2.2
I have added a UITapGestureRecognizer to a view, but when I click it the method is not being called.
func addTapGestuere(uiview: UIView) {
let tapGestureRecognizer:UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: Selector("cardTapped:"))
uiview.addGestureRecognizer(tapGestureRecognizer)
}
I run this on the viewDidload
self.addTapGestuere(self.Card1View)
self.addTapGestuere(self.Card2View)
I put a break point on the method
cardTapped(recognizer: UITapGestureRecognizer) {
}
but when I click on the image the method isnt called. I have user interaction enabled for all the views.
Be careful about the following:
The UIView you are trying to add the UITapGestureRecognizer has userInteractionEnabled set to true:
self.view.userInteractionEnabled = true
The UIView you are trying to get the tap to has no other views covering it. Use the View Debugger to confirm this.
Most importantly, make sure you are adding the UITapGestureRecognizer to the correct UIView. Adding it to self.view will add it to the UIViewController's view.
As a side note: You can add the UITapGestureRecognizer using the Inetrface Builder itself, then connecting IBAction for the same. Will reduce the probability of simple mistakes.
I want one of my screens to be accessed only if the user taps three times on a button within a second. eg. if there's a button on View controller A, a user should tap 3 times within a second on that button to get to View Controller B.
Any help is appreciated!
Buttons are not set up to respond to multiple taps. You'll have to simulate that yourself.
As others have said, you can create a tap gesture recognizer and attach it to any view. For some views you'll need to set the userInteractionEnabled flag to true before it will respond though.
If you want a button to handle double-taps you'll need to have the button with no action installed but a 2 click gesture recognizer attached.
You need to add tap gesture recogniser to your custom View.
-(void)handleTapGesture:(UITapGestureRecognizer *)tapGestureRecognizer{
NSLog(#"3 tapped");
//add code to present another View Controller
}
-(void)buttonView{
UITapGestureRecognizer *tapGestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleTapGesture:)];
tapGestureRecognizer.numberOfTapsRequired=3;
[self.customButtonView addGestureRecognizer:tapGestureRecognizer];
}
Swift:
func handleTapGesture(tapGestureRecognizer: UITapGestureRecognizer) {
NSLog("3 tapped")
//add code to present another View Controller
}
func buttonView() {
var tapGestureRecognizer: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: "handleTapGesture:")
tapGestureRecognizer.numberOfTapsRequired = 3
self.customButtonView.addGestureRecognizer(tapGestureRecognizer)
}
You can call this method in viewDidAppear.
I have a UIView, in which I have one UILabel. I would like to change the UILabel.Font to a custom UIFont when the UIView is tapped (This enlarges the tappable area instead of using a UIButton).
To add the UITapGestureRecognizer, I use the following code:
var gestureRecognizer = new UITapGestureRecognizer ((item) => {
(item.View.Subviews[0] as UILabel).Font = Constants_iOS.FONT_OS_SMALL_LABEL_SEMIBOLD;
});
view.AddGestureRecognizer (gestureRecognizer);
The font change gets executed, and stepping through the code shows the font changing. But it does not update in the UI, and all subsequent executions of the function also start with the Font being the old one.
What is going wrong?
Add tap selector method.
let tap = UITapGestureRecognizer(target: self, action: Selector("handleTap:"))
tap.delegate = self
view.addGestureRecognizer(tap)
func handleTap(sender:UIGestureRecognizer){
//change your font here
}
Please note that a UITableview header gets redrawn each time it gets tapped. So your font change will not persist.