How to adjust view size for iPad and iPhone 4S without storyboard?

Question

I don't know how to adjust view size for iPad and iPhone 4S without storyboard.

Is Auto layout used only in storyboard? Can't I set it by code?

And for example, if I make the game that has different things depends on the stage, using storyboard is not the right way I think...

Is there a good way to adjust view size for iPad and iPhone 4s without storyboard?

Answer 1

The answer to your question is: Yes.

It is fairly straightforward to use autolayout without IB. But there are a number of steps involved.

Here's a quick example of setting a subview to be the same size at the main view in a viewController (could be in viewDidLoad(), viewWillAppear(), etc.)

self.view.addSubview(viewToAutosize)
viewToAutosize.translatesAutoresizingMaskIntoConstraints = false
viewToAutosize.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
viewToAutosize.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
viewToAutosize.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
viewToAutosize.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true

Some gotchas:

you need to set translatesAutoresizingMaskIntoConstraints to false on the view you wish to autosize.

you can't modify the constraints unless the view is already added as a subview (the view you are constraining against needs to be in the same view hierarchy -- see the first line of code above).

you have to activate the constraints manually. I have shown just one possible way to do it.

You should google auto "layout programmatically" (without the quotes) and pick a tutorial, video or apple documentation you are comfortable with to learn more. There's a lot you can do with auto layout, and it is definitely the future, since more device sizes are being added all the time.