我试图计算基于不同字符串长度的UILabel的高度。
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
}
上面是我用来确定高度的当前函数，但它不起作用。如果能得到任何帮助，我将不胜感激。我更喜欢Swift的答案，而不是Objective C。
extension String{
func widthWithConstrainedHeight(_ height: CGFloat, font: UIFont) -> CGFloat {
let constraintRect = CGSize(width: CGFloat.greatestFiniteMagnitude, height: height)
let boundingBox = self.boundingRect(with: constraintRect, options: NSStringDrawingOptions.usesLineFragmentOrigin, attributes: [NSFontAttributeName: font], context: nil)
return ceil(boundingBox.width)
}
func heightWithConstrainedWidth(_ width: CGFloat, font: UIFont) -> CGFloat? {
let constraintRect = CGSize(width: width, height: CGFloat.greatestFiniteMagnitude)
let boundingBox = self.boundingRect(with: constraintRect, options: NSStringDrawingOptions.usesLineFragmentOrigin, attributes: [NSFontAttributeName: font], context: nil)
return ceil(boundingBox.height)
}
}
这是我在Swift 4.1和Xcode 9.4.1中的答案
//This is your label
let proNameLbl = UILabel(frame: CGRect(x: 0, y: 20, width: 300, height: height))
proNameLbl.text = "This is your text"
proNameLbl.font = UIFont.systemFont(ofSize: 17)
proNameLbl.numberOfLines = 0
proNameLbl.lineBreakMode = .byWordWrapping
infoView.addSubview(proNameLbl)
//Function to calculate height for label based on text
func heightForView(text:String, font:UIFont, width:CGFloat) -> CGFloat {
let label:UILabel = UILabel(frame: CGRect(x: 0, y: 0, width: width, height: CGFloat.greatestFiniteMagnitude))
label.numberOfLines = 0
label.lineBreakMode = NSLineBreakMode.byWordWrapping
label.font = font
label.text = text
label.sizeToFit()
return label.frame.height
}
现在你调用这个函数
//Call this function
let height = heightForView(text: "This is your text", font: UIFont.systemFont(ofSize: 17), width: 300)
print(height)//Output : 41.0
斯威夫特5:
如果你有UILabel和某种方式boundingRect不为你工作(我面临这个问题。它总是返回1行高)有一个扩展，可以轻松计算标签大小。
extension UILabel {
func getSize(constrainedWidth: CGFloat) -> CGSize {
return systemLayoutSizeFitting(CGSize(width: constrainedWidth, height: UIView.layoutFittingCompressedSize.height), withHorizontalFittingPriority: .required, verticalFittingPriority: .fittingSizeLevel)
}
}
你可以这样使用它:
let label = UILabel()
label.text = "My text\nIs\nAwesome"
let labelSize = label.getSize(constrainedWidth:200.0)
对我有用
这个解决方案将有助于在运行时计算高度和宽度。
let messageText = "Your Text String"
let size = CGSize.init(width: 250, height: 1000)
let options = NSStringDrawingOptions.usesFontLeading.union(.usesLineFragmentOrigin)
let estimateFrame = NSString(string: messageText).boundingRect(with: size, options: options, attributes: [NSAttributedString.Key.font: UIFont(name: "HelveticaNeue", size: 17)!], context: nil)
在这里，你可以计算你的字符串的估计高度，并将其传递给UILabel框架。
estimateFrame.Width
estimateFrame.Height
