I am trying to learn Swift. I currently have a button that plays an animation but I want to have the animation start immediately after the app loads. How would I go about doing that?
You need to put your animation on the viewDidApear method, while will be called after your viewDidLoad method.
For example
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
UIView.animateWithDuration(2, animations: {
//do what ever here
})
}
Your question is not very specific so I'm not sure if this answers your question.
When your iOS application starts, there is usually a View Controller that gets rendered on the screen as your main entry point. This can be changed in in your AppDelegate.swift
Now, let's assume that in your application, a view controller named WelcomeViewController is the first page and you have your button along with the rest of your logic in it. Every view controller has certain functions that you can override and use. For example:
viewDidLoad
viewDidAppear
viewWillAppear
viewWillDisappear
the names are self-explanatory so I'm sure you can guess what they do. In your case, just override viewDidAppear and start your animation in there.
override func viewDidAppear(animated: Bool) {
...
}
Related
I am going to detect the swiping or selecting tab event in XLPagerTabStrip library in Swift 4.
I only need to get the tab index whenever selected tab is changed.
So I have checked library in Github but not found any good solutions.
thanks.
So I didn't find a solution from the library itself but, I used viewWillDisappear and for every time you swipe away of the view this function will be called.
Should be written as follows in your child view controller:
override func viewWillDisappear(_ animated: Bool) {
//Do your thing here
}
You can read more about this callback function here.
You can simply override updateContent
override func updateContent() {
super.updateContent()
// your code ....
}
I currently facing an issue trying to delegate SWRevealViewController panGestureRecognizer method in one of my view.
When i slide my UISlider, the panGesture interfer and open the sidemenu instead to move my slider.
i tried to delegate the panGesture and it works well, but if i quit my view and go to an other, the pangesture is not functionnal anymore, and i can't reveal my sidemenu from my second view.
My code :
class Search : UIViewController, UIGestureRecognizerDelegate{
#IBOutlet weak var sliderprice: UISlider!
override func viewDidLoad() {
super.viewDidLoad()
self.revealViewController().panGestureRecognizer().delegate = self
}
override func viewDidAppear(animated: Bool) {
self.view.addGestureRecognizer(self.revealViewController().panGestureRecognizer())
}
func gestureRecognizer(gestureRecognizer: UIGestureRecognizer, shouldReceiveTouch touch: UITouch) -> Bool {
if (touch.view == self.sliderprice){
return false
}
else{
return true
}
}
}
While this is an old question, I'll answer it anyways, maybe for someone coming from Google search it will be helpful.
After many hours of research and thinking, finally I was able to come up with multiple solutions to this problem.
The Lazy
This solution is not recommended, but working, so I decided to list it.
Before setting self as self.revealViewController().panGestureRecognizer()'s delegate, store the original self.revealViewController().panGestureRecognizer().delegate to a property, and when you leave the screen at viewWillDisappear(), set self.revealViewController().panGestureRecognizer().delegate back to the one you stored in viewDidLoad(). So in the end it gets back its original delegate. Tampering with delegates like this is never really recommended, but I said, it works.
The Nicer One
I consider this still not the best solution, but we are getting there. Find a class, a controller that you use in the whole application and gets called when you start the app. Here set the SWRevealViewController's panGestureDelegate to this class, and overwrite the gestureRecognizerShouldBeginmethod appropriately (see below).
The Best One - (in my opinion)
Now this is the best and most clear solution.
For the time being (May, 2018) the last commit to SWRevealViewController was in 2015.
Fork the original project ( https://github.com/John-Lluch/SWRevealViewController ) or simply copy the two necessary files (SWRevealViewController.m and SWRevealViewController.h) and place them into a separate folder to handle 3rd party libraries. Then you can remove SWRevealViewController from your Podfile. Don't forget to fix your imports for SWRevealViewController where you have it.
Now you are free to modify the files. What I suggest is the following.
Go to SWRevealViewController.m and implement the following method:
-(BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer
shouldReceiveTouch:(UITouch *)touch
{
return ![touch.view isKindOfClass:UISlider.class];
}
If the touched view is a UISlider (or a custom class that inherits from UISlider) the gesture won't begin, meaning the pan gesture will no longer be conflicted with the UISlider's pan gesture.
I seriously hope I could help anyone out there as this problem was a pain in my back for quite some time now.
My app allows users to view another users info by tapping their avatar, at which they can block that user so that their message content is not visible.
What is the best way when returning to the chat view to clear the messages and reload them?
This would allow my blocking code to work on the fly. Currently it works when I dismiss the chat view and return but not when jump to another view and then back to the chat view.
Ive tried self.collectionView!.reloadData() but that does not do anything.
All you need is to implement
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
self.collectionView?.reloadData()
}
that is called when you come back from an already instantiated view.
Call the reloadData method after a delay.
self.performSelector(#selector(self.delayReload), withObject: nil, afterDelay: 0.1)
func delayReload() {
self.collectionView.reloadData()
}
Hope this will help you.
Sincerely,
Harri.
I am making an app for OS X with Cocoa with Xcode and I want to change the Windows background color with alpha in swift. I don't know how to call the window from the code and how to set its background color with alpha value. How can I do that?
Here is my app delegate class, with hierarchy:
Perhaps the AppDelegate is not the right place to add it if you are using storyboards. There is an easy way by modifying the view's layer:
In Interface Builder, select the child view that is held by the view controller of the Window.
Go to the the view's Effects Inspector and enable Core Animation Layer.
Add this line of code in your viewDidLoad() method (viewcontroller.swift):
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
self.view.wantsLayer = true;
self.view.layer?.backgroundColor = NSColor.whiteColor().CGColor
}
Thanks for the code and pictures to the Core Animation. That solved most of my problems. I then found that because more was going on later with windows that I needed to move your code to viewWillAppear. It has been much more predictable there. I got this information from another question on SO and thought I would update this thread as well since it was my starting point on the problem.
The following goes in viewController.swift after you have enabled Core Animation Layer for the View in the Effects Inspector.
override func viewWillAppear(_ animated: Bool)
super.viewWillAppear(animated)
self.view.layer?.backgroundColor = NSColor.redColor().CGColor
}
I have created a local notification in Swift which gives the option to end a current game without having to go back in to the app. That's all fine and works as it should. The issue I'm having is that if the user does this, I don't want them to go back to the Game view controller if that happens to be the last view that was open when the app entered the background. I would like them to go back to the app's Home view controller instead.
I expected to be able to add a perform segue to my Game view controller in the following way, should the criteria match. I tried adding it to viewDidAppear(), but it didn't work:
override func viewDidAppear(animated: Bool) {
if isThereACurrentGame() == false {
performSegueWithIdentifier("unwindToHomeScreen", sender: self)
}
}
Is this something to do with viewDidAppear() not being called when the app comes back to the foreground? If so, what might an alternative be?
P.S. My isThereACurrentGame() function works as it should, as does the performSegueWithIdentifier elsewhere in the view controller, so these aren't the cause of the problem.