Resize textField Based On Content

问题

How can a textField be resized based on content while using auto-layout in an iOS application written in Swift?

The text field will resize as necessary to fit its content when the view loads as well as while the user is typing.

Ideally, the text field would stop resizing at a certain point, say, 6 lines, and become scrollable.

回答1:

You have to use an UITextView instead of an UITextField.

Then, you can use the sizeThatFits method.

But first you have to know how high one line will be. You can get that information by using lineHeight:

var amountOfLinesToBeShown: CGFloat = 6
var maxHeight: CGFloat = yourTextview.font.lineHeight * amountOfLinesToBeShown

After that, just call the sizeThatFits method inside your viewDidLoad method and set the maxHeight (line * 6) as your textview height:

yourTextview.sizeThatFits(CGSizeMake(yourTextview.frame.size.width, maxHeight))

回答2:

Swift 3

var textView : UITextView!

override func viewDidLoad() {
    super.viewDidLoad()
    textView = UITextView()
    textView.sizeThatFits(CGSize(width: textView.frame.size.width, height: textView.frame.size.height))
}

来源：https://stackoverflow.com/questions/28389913/resize-textfield-based-on-content