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iosobjective-ciphoneviewcontrollerscene

Difference between a Scene and a View in iOS

I'm new to iOS I'm having trouble understanding the difference between scene and a view. Unfortunately Apple's documentation isn't helping me. I read that a scene is what you see on the screen. But isn't that what a view is? Are these two interchangeable terms? If not what are the differences, both functionality and best practice? How does a ViewController come into play for both of these?

Any explanations or links are much appreciated.

Solution

  • In simple terms:

    View

    A UIView is a rectangular area that is displayed on the screen.

    ViewController

    A collection of Views displayed on the screen at the moment.

    In the following image, blue area and yellow area are Views, whereas the entire screen is a ViewController.

    Anatomy of a UIView

    Scene

    A ViewController which is a part of a specific sequence.

    enter image description here

    However, the technical definitions are a little different:

    UIView

    A UIIView is a wrapper to CALayer. It holds an array of subviews which implies that it's a collection of views by itself. You can imagine this as a tree structure.

    ViewController

    A ViewController is a controller which holds a reference to the root view. This way, you can traverse the leaf node or any subview from the controller.

    Scene

    "Scene" is another term for a ViewController in one context of storyboard.