swift 关键词高亮

/// 获取字符出现的位置信息(支持多次位置获取)
   /// - Parameter string: 原始文本
   /// - Parameter inString: 需要查找的字符
   private func rangeOfString(string:NSString,
                              andInString inString:String) -> [NSRange] {
       
       var arrRange = [NSRange]()
       var _fullText = string
       var rang:NSRange = _fullText.range(of: inString)
       
       while rang.location != NSNotFound {
           var location:Int = 0
           if arrRange.count > 0 {
               if arrRange.last!.location + arrRange.last!.length < string.length {
                    location = arrRange.last!.location + arrRange.last!.length
               }
           }

           _fullText = NSString.init(string: _fullText.substring(from: rang.location + rang.length))

           if arrRange.count > 0 {
                 rang.location += location
           }
           arrRange.append(rang)
           
           rang = _fullText.range(of: inString)
       }
       
       return arrRange
   }

/// 批量设置富文本
    /// - Parameter textFont: 默认文本
    /// - Parameter textColor: 默认文本颜色
    /// - Parameter changeTexts: 需要改变的文本
    /// - Parameter changFonts: 需要改变的字体
    /// - Parameter changeColors: 需要改变的颜色
    /// - Parameter isLineThrough: 是否下划线
    func setAttributeStringTexts(FullTextFont textFont:UIFont,
                                 andFullTextColor textColor:UIColor,
                                 withChangeTexts changeTexts:[String],
                                 withChangeFonts changFonts:[UIFont],
                                 withChangeColors changeColors:[UIColor],
                                 isLineThrough:Bool = false) -> NSAttributedString{
        
        let strFullText:String = self
        
        var range:NSRange?
        var dicAttr:[NSAttributedString.Key:Any]?
        let attributeString = NSMutableAttributedString.init(string: strFullText)
        
        //不需要改变的文本
        range = NSString.init(string: strFullText).range(of: String.init(strFullText))
        
        dicAttr = [
            NSAttributedString.Key.font:textFont,
            NSAttributedString.Key.foregroundColor:textColor,
        ]
        attributeString.addAttributes(dicAttr!, range: range!)
        
        //需要改变的文本
        var index:Int = 0
        for item in changeTexts {
            //range = NSString.init(string: strFullText).range(of: item)
            let ranges = self.rangeOfString(string: NSString.init(string: strFullText), andInString: item)
 
            for range in ranges {
                dicAttr = [
                    NSAttributedString.Key.font:changFonts.count > index ? changFonts[index] : changFonts.first as Any,
                    NSAttributedString.Key.foregroundColor:changeColors.count > index ? changeColors[index] : changeColors.first as Any,
                ]
                
                if isLineThrough {
                    dicAttr?[NSAttributedString.Key.strikethroughStyle] = NSNumber.init(value: 1)
                }
 
                if range.location + range.length <= fullString.length {
                    attributeString.addAttributes(dicAttr!, range: range)
                }
            }
            
            index += 1
        }
        
        return attributeString
    }