iOS / Swift：是否可以有选择地更改UITextView部分的字体？

Question

是否可以有选择地更改 UITextView 部分的字体？

我有一个 UITextView ，并希望有选择地更改部分字体的大小和样式。例如

  

Lorem ipsum dolor 坐在el elit lamet，consectetaur cillium adipisicing   pecu，sed do eiusmod tempor incididunt ut labore et dolore magna   aliqua。广告 minim veniam

Answer 1

您可以使用NSAttributedString使用addAttribute方法为字符串赋予属性。

 let string = "Bold Italics Roman"
 let attributes = [NSFontAttributeName: UIFont(name: "Open Sans", size: 18.0)!]
 let attributedText = NSMutableAttributedString(string: string, attributes: attributes)

 let sampleString = string as NSString
 let range  = sampleString.range(of: "Italics")
 attributedText.addAttribute(NSFontAttributeName, value: UIFont(name: "OpenSans-Italic", size: 18.0)!, range: range)

 textView.attributedText = attributedText

Answer 2

我们可以使用NSString和rangeofString：method

来实现这一点

let longString = "Lorem ipsum dolor. VeryLongWord ipsum foobar"
let longestWord = "VeryLongWord"

let longestWordRange = (longString as NSString).rangeOfString(longestWord)

let attributedString = NSMutableAttributedString(string: longString, attributes: [NSFontAttributeName : UIFont.systemFontOfSize(20)])

attributedString.setAttributes([NSFontAttributeName : UIFont.boldSystemFontOfSize(20), NSForegroundColorAttributeName : UIColor.redColor()], range: longestWordRange)


label.attributedText = attributedString