根据Swift中的String计算出UILabel的大小 [英] Figure out size of UILabel based on String in Swift
本文介绍了根据Swift中的String计算出UILabel的大小的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我正在尝试根据不同的字符串长度来计算UILabel的高度。
I am trying to calculate the height of a UILabel based on different String lengths.
func calculateContentHeight() -> CGFloat{
var maxLabelSize: CGSize = CGSizeMake(frame.size.width - 48, CGFloat(9999))
var contentNSString = contentText as NSString
var expectedLabelSize = contentNSString.boundingRectWithSize(maxLabelSize, options: NSStringDrawingOptions.UsesLineFragmentOrigin, attributes: [NSFontAttributeName: UIFont.systemFontOfSize(16.0)], context: nil)
print("\(expectedLabelSize)")
return expectedLabelSize.size.height
}
以上是我用来确定高度但不起作用的当前函数。我非常感谢能得到的任何帮助。我会在Swift而不是Objective C中给出答案。
Above is the current function I use to determine the height but it is not working. I would greatly appreciate any help I can get. I would perfer the answer in Swift and not Objective C.
推荐答案
在 String上使用扩展名
extension String {
func height(withConstrainedWidth width: CGFloat, font: UIFont) -> CGFloat {
let constraintRect = CGSize(width: width, height: .greatestFiniteMagnitude)
let boundingBox = self.boundingRect(with: constraintRect, options: .usesLineFragmentOrigin, attributes: [NSFontAttributeName: font], context: nil)
return ceil(boundingBox.height)
}
func width(withConstrainedHeight height: CGFloat, font: UIFont) -> CGFloat {
let constraintRect = CGSize(width: .greatestFiniteMagnitude, height: height)
let boundingBox = self.boundingRect(with: constraintRect, options: .usesLineFragmentOrigin, attributes: [NSFontAttributeName: font], context: nil)
return ceil(boundingBox.width)
}
}
以及 NSAttributedString
(这在某些时候非常有用)
and also on NSAttributedString
(which is very useful at times)
extension NSAttributedString {
func height(withConstrainedWidth width: CGFloat) -> CGFloat {
let constraintRect = CGSize(width: width, height: .greatestFiniteMagnitude)
let boundingBox = boundingRect(with: constraintRect, options: .usesLineFragmentOrigin, context: nil)
return ceil(boundingBox.height)
}
func width(withConstrainedHeight height: CGFloat) -> CGFloat {
let constraintRect = CGSize(width: .greatestFiniteMagnitude, height: height)
let boundingBox = boundingRect(with: constraintRect, options: .usesLineFragmentOrigin, context: nil)
return ceil(boundingBox.width)
}
}
Swift 4
只需在扩展名字符串
方法中更改属性
的值
来自
[NSFontAttributeName: font]
到
[.font : font]
这篇关于根据Swift中的String计算出UILabel的大小的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
查看全文