How do I fix unrecognized selector sent to instance?
Table of Contents
How do I fix unrecognized selector sent to instance?
The “Unrecognized selector sent to instance” is an annoying error in Xcode….Fixing «Unrecognized Selector Sent To Instance»
- First, check that the selector is called on the right object. The function name should exist on that object.
- Then, check the function name.
- Then, check the function parameters.
What does unrecognized selector sent to instance mean?
Once you run this line of code you will instantly get an error message in the console area, which look s like this (unrecognized selector sent to instance). Since the selector is another name for the method, the error is basically saying that it doesn’t recognize the function that you’re trying to call on this object.
What is a selector in Xcode?
A selector is the name used to select a method to execute for an object, or the unique identifier that replaces the name when the source code is compiled.
What is a selector in iOS Swift?
In Objective-C, a selector is a type that refers to the name of an Objective-C method. In Swift, Objective-C selectors are represented by the Selector structure, and you create them using the #selector expression.
What is @objc func in Swift?
That’s where the @objc attribute comes in: when you apply it to a class or method it instructs Swift to make those things available to Objective-C as well as Swift code.
Why do we need @objc?
private mean it visible only in Swift. so use @objc to visible in Objective-C. If you have a func to selector a private func in swift, it is required. The @objc attribute makes your Swift API available in Objective-C and the Objective-C runtime.
What is gesture recognizer in Swift?
A gesture-recognizer object—or, simply, a gesture recognizer—decouples the logic for recognizing a sequence of touches (or other input) and acting on that recognition.
What is UIView in Swift?
UIView can be defined as an object by using which we can create and manage the rectangular area on the screen. We can have any number of views inside a view to create a hierarchical structure of the UIViews.
What does @objc do in Swift?
What does @objc mean in Swift?
@objc means you want your Swift code (class, method, property, etc.) to be visible from Objective-C. dynamic means you want to use Objective-C dynamic dispatch.
What is AppDelegate in Swift?
So an app delegate is an object that the application object can use to do certain things like display the first window or view when the app starts up, handle outside notifications or save data when the app goes into the background.
What is @MainActor in Swift?
@MainActor is a global actor that uses the main queue for executing its work. In practice, this means methods or types marked with @MainActor can (for the most part) safely modify the UI because it will always be running on the main queue, and calling MainActor.
How do you use UIPinchGestureRecognizer?
iOS UIGestureRecognizer UIPinchGestureRecognizer Pinches are a two fingered gesture where the fingers move closer or farther from each other. This gesture is generally used for resizing a view.
Should I call super loadView?
You definitely should not be calling [super loadView] . I’d say you found a bug in the ZoomingPDFViewer example. You override loadView when you want to programatically create the view hierarchy for your view controller (not using a xib). As you pointed out, the docs clearly state that you should not call super.
