Adding buttons programmatically to stackView in Swift

问题

I've tried to add buttons dynamically/programmatically in UIStackView that I've built with interface builder but they failed to show up when I run the application. The number of buttons that's supposed to be added ranging normally from 4-6. Can you guys tell me what's wrong with the code

回答1:

@Nowonder I just recreate what you are trying to achieve. The following are the steps.

Add a UIStackView in viewController from Interface Builder and add required constraints.

Add the following code.

override func viewDidLoad() {
   super.viewDidLoad()

   let button = UIButton()
   button.setTitle("btn 1", for: .normal)
   button.backgroundColor = UIColor.red
   button.translatesAutoresizingMaskIntoConstraints = false

   let button2 = UIButton()
   button2.setTitle("btn 2", for: .normal)
   button2.backgroundColor = UIColor.gray
   button2.translatesAutoresizingMaskIntoConstraints = false

   let button3 = UIButton()
   button3.setTitle("btn 3", for: .normal)
   button3.backgroundColor = UIColor.brown
   button3.translatesAutoresizingMaskIntoConstraints = false

   buttonStackView.alignment = .fill
   buttonStackView.distribution = .fillEqually
   buttonStackView.spacing = 8.0

   buttonStackView.addArrangedSubview(button)
   buttonStackView.addArrangedSubview(button2)
   buttonStackView.addArrangedSubview(button3)  

}

Following is the outcome.

Hope it helps.

回答2:

I think you need to do few more steps before the button will start showing up.

Add the stack view to current view's subviews
```
view.addSubview(buttonStackView)
```

Now each of these views buttons, as well as the stackView, needs to set the translatesAutoresizingMaskIntoConstraints to false.

button1.translatesAutoresizingMaskIntoConstraints = false
button2.translatesAutoresizingMaskIntoConstraints = false
buttonStackView.translatesAutoresizingMaskIntoConstraints = false

Now set the stackView contraints

NSLayoutConstraint.activate([
    buttonStackView.topAnchor.constraint(equalTo: view.topAnchor),
    buttonStackView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
    buttonStackView.bottomAnchor.constraint(equalTo: view.bottomAnchor),
    buttonStackView.trailingAnchor.constraint(equalTo: view.trailingAnchor)])

You will need to provide the constraints, or can override the intrinsic size of stackView.
```
 override func intrinsicContentSize() -> CGSize
 {
   return CGSizeMake(200, 40)
 }
```

As UILabel have the intrinsic size and so, the button will show, if not you will have to set the constraints for them also to be safe.

回答3:

SOLVED!

The button showed up when I set the type of the button with the instance method init(type:)

来源：https://stackoverflow.com/questions/58162441/adding-buttons-programmatically-to-stackview-in-swift

标签

ios

swift

uistackview