iOS Tutorial Define Views
How to Define Views
In iOS, a view object means anything that is capable of drawing itself in a rectangular region on an iOS screen.
- For example, a label is a view object, and a button is another view object.
- When you are looking at the user interface of any random iOS application, that one screen might contain 5 or 10 or maybe more than 20 different view objects.
- Some views are large, and some are tiny. Some views might show an image; some might show text, some might show both.
Let's back in the code for the FirstApp project. In ViewController.swift file we are using a view
to change the background color.
- This view is an object that already exists as part of the storyboard.
- It is not referring to any of the view objects we have added, because when you create a new Xcode project, and you will also get that first storyboard.
- It included the outline of a single screen, and it is simply called view.
Now we might describe this as empty, but it is not, because it is a view object configured to draw itself and to fill all available screen size on whatever device it runs on.


So as this is our top-level view object, all these labels and this button are inside it, so they are all subviews of the top-level view. This idea of views with subviews inside them is useful because in the code we could ask this top-level view to give all of its subviews.