最近在开发中，遇到一个奇怪的问题，就是当显示一串文本，当文本最后一个字符是Emoji时，Emoji显示乱码，如图：
错误展示
正确展示应该是这样的
正确展示
而展示逻辑也很简单，一个UILabel控件通过attributedText展示
signLabel.attributedText = user.introductionAttribute
如果用label.text展示的话，则是正常的
signLabel.text= user.introduction
直接说问题点和解决方案：
var introductionAttribute: NSAttributedString { let attributedString = NSMutableAttributedString(string: introduction, attributes: [.font: YRUserHeaderLayoutable.introFont]) let paragraphStyle = NSMutableParagraphStyle() paragraphStyle.paragraphSpacing = 0 paragraphStyle.firstLineHeadIndent = 0 paragraphStyle.headIndent = 0 paragraphStyle.paragraphSpacingBefore = 0 attributedString.addAttribute(NSAttributedString.Key.paragraphStyle, value: paragraphStyle, range: NSRange(location: 0, length: introduction.count)) return attributedString }
问题出在了最后一行代码
attributedString.addAttribute(NSAttributedString.Key.paragraphStyle, value: paragraphStyle, range: NSRange(location: 0, length: introduction.count))
在计算字符串长度时， Swift计算的是
/// The number of characters in a string. public var count: Int { get }
let swiftCount = introduction.count let ocLength = (introduction as NSString).length print("introducetion:\(introduction)") print("swiftCount:\(swiftCount)") print("ocLength:\(ocLength)")
打印：
introducetion:这是一个emoji😁 swiftCount:10 ocLength:11
当用Swift.count计算长度时出错，修复也很简单，
attributedString.addAttribute(NSAttributedString.Key.paragraphStyle, value: paragraphStyle, range: NSRange(location: 0, length: (introduction as NSString).length))
