ios - 'sizeWithFont(_:constrainedToSize:lineBreakMode :)'不可用:使用-boundingRectWithSize:options:attributes:context:

我必须根据文本扩展TextView的大小，但它显示了问题，但我无法修复它，因此请帮助我修复此问题。我发布了我尝试的代码。

var size: CGSize = text.sizeWithFont(UIFont.boldSystemFontOfSize(13), constrainedToSize: textSize, lineBreakMode:NSLineBreakMode.ByWordWrapping)

最佳答案

我把答案从this ObjC question翻译成Swift；可能让你绊倒的是你需要将String转换成NSString。
斯威夫特4

let text = "Hello"
let font = UIFont.systemFont(ofSize: UIFont.systemFontSize)
let maxSize = CGSize(width: 100, height: CGFloat.greatestFiniteMagnitude)

let size = (text as NSString).boundingRect(with: maxSize,
        options: [.usesLineFragmentOrigin, .usesFontLeading],
        attributes: [NSFontAttributeName:font],
        context: nil)
    .size

斯威夫特3

let text = "Hello"
let font = UIFont.systemFontOfSize(UIFont.systemFontSize())
let maxSize = CGSize(width: 100, height: CGFloat.max)

let size = (text as NSString).boundingRectWithSize(maxSize,
        options: [.UsesLineFragmentOrigin, .UsesFontLeading],
        attributes: [NSFontAttributeName:font],
        context: nil)
    .size

关于ios - 'sizeWithFont(_:constrainedToSize:lineBreakMode :)'不可用:使用-boundingRectWithSize:options:attributes:context:，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/36374137/