如何在UItextField中添加不同字体的字符串？

// 创建一个NSMutableAttributedString对象
let attributedString = NSMutableAttributedString(string: "Hello World!")

// 设置第一个字母为红色、粗体
attributedString.addAttribute(.foregroundColor, value: UIColor.red, range: NSRange(location: 0, length: 1))
attributedString.addAttribute(.font, value: UIFont.boldSystemFont(ofSize: 16), range: NSRange(location: 0, length: 1))

// 设置第六个字母为蓝色、斜体
attributedString.addAttribute(.foregroundColor, value: UIColor.blue, range: NSRange(location: 5, length: 1))
attributedString.addAttribute(.font, value: UIFont.italicSystemFont(ofSize: 16), range: NSRange(location: 5, length: 1))

// 将NSAttributedString赋值给UITextField的attributedText属性
textField.attributedText = attributedString