Question

我想自动调整UITextView类似于sms-app或whatsapp。我只找到了objective-c的解决方案，示例项目的代码太多了。我在Swift中需要这个。

问：在用户输入带有换行符的消息时，如何按字体大小调整UITextView的大小？

Answer 1

您可以使用UITextViewDelegate执行此操作。我不知道如何使用AutoLayout实现这一目标。

func textViewDidChange(textView: UITextView)
    {
        var fixedWidth : CGFloat = textView.frame.size.width
        var newSize : CGSize = textView.sizeThatFits(CGSizeMake(fixedWidth, CGFloat(MAXFLOAT)))
        var newFrame : CGRect = textView.frame
        newFrame.size = CGSizeMake(CGFloat(fmaxf((Float)(newSize.width), (Float)(fixedWidth))),newSize.height)

        textView.frame = newFrame
    }

Answer 2

var textStorage: NSTextStorage!
var layoutManager: NSLayoutManager!
var textContainer: NSTextContainer!
var textPreview: UITextView!

 override func viewDidLoad() {
    super.viewDidLoad()

    textStorage = NSTextStorage()
    layoutManager = NSLayoutManager()
    textStorage.addLayoutManager(layoutManager)

    let newTextViewRect = view.bounds
    let containerSize = CGSize(width: newTextViewRect.width, height: CGFloat.max + 5)

    textContainer = NSTextContainer(size: containerSize)
    layoutManager.addTextContainer(textContainer)

    textPreview = UITextView(frame: newTextViewRect, textContainer: textContainer)
    textPreview.font = UIFont(name: "Helvetica", size: 16)
    view.addSubview(textPreview)

    configureView()

    let length = count(textPreview.text)
    let range:NSRange = NSMakeRange(length , 1)
    textPreview.scrollRangeToVisible(range)

}

override func viewDidLayoutSubviews() {
    textPreview.frame = view.bounds
}

使用autolayout快速增长UITextView

2 个答案: