无法使用类型为"NSAttributedStringKey"的索引下标"[String:AnyObject]"类型的值

Question

我在我的项目中使用下面的代码.更新到swift 4后,我收到错误.我该如何解决？

码:

let returnString : NSAttributedString

   if styleList.count > 0
   {
       var attrs = [String:AnyObject]()
       attrs[NSAttributedStringKey.font] = codeFont
       for style in styleList
       {
         if let themeStyle = themeDict[style]
         {
             for (attrName, attrValue) in themeStyle
             {
                 attrs.updateValue(attrValue, forKey: attrName)
             }
         }
     }

     returnString = NSAttributedString(string: string, attributes:attrs )
 }

这是错误:

---

无法使用类型为"NSAttributedStringKey"的索引下标"[String:AnyObject]"类型的值

---

无法将'[String:AnyObject]'类型的值转换为预期的参数类型'[NSAttributedStringKey:Any]？'

Answer 1

在swift 4中 - NSAttributedString表示完全改变了.

更换你的属性字典attrs类型[String:AnyObject]与[NSAttributedStringKey:Any]

试试这个:

let returnString : NSAttributedString

   if styleList.count > 0
   {
       var attrs = [NSAttributedStringKey:Any]()  // Updated line 
       attrs[NSAttributedStringKey.font] = codeFont
       for style in styleList
       {
         if let themeStyle = themeDict[style]
         {
             for (attrName, attrValue) in themeStyle
             {
                 attrs.updateValue(attrValue, forKey: attrName)
             }
         }
     }

     returnString = NSAttributedString(string: string, attributes:attrs )
 }

以下是Apple的说明:NSAttributedString - 创建NSAttributedString对象