NSAttributedString

NSAttributedString 对象管理字符和字符串关联的属性（例如，字体和字距调整）， 使用单个字符或字符串。 通过属性字符串对字符和字符属性进行关联。
属性字符有两个公共类簇 NSAttributedString 和 NSMutableAttributedString。一个是字符可变的一个是字符不可变的。

@available(iOS 3.2, *)
open class NSAttributedString : NSObject, NSCopying, NSMutableCopying, NSSecureCoding {

    // 获取字符的长度
    open var string: String { get }

    // 获取属性数组
    open func attributes(at location: Int, effectiveRange range: NSRangePointer?) -> [String : Any]
}

extension NSAttributedString {

     // 获取字符长度 
    open var length: Int { get }

     // 获取属性 
    open func attribute(_ attrName: String, at location: Int, effectiveRange range: NSRangePointer?) -> Any?
  
     // 获取属性字字符串
    open func attributedSubstring(from range: NSRange) -> NSAttributedString

    
    open func attributes(at location: Int, longestEffectiveRange range: NSRangePointer?, in rangeLimit: NSRange) -> [String : Any]

    open func attribute(_ attrName: String, at location: Int, longestEffectiveRange range: NSRangePointer?, in rangeLimit: NSRange) -> Any?

    // 比较连个字符串是否相等
    open func isEqual(to other: NSAttributedString) -> Bool

    /*******************  构造方法  *********************/
    // 通过一个字符串创建
    public init(string str: String)

    // 通过字符串 + 属性文本创建
    public init(string str: String, attributes attrs: [String : Any]? = nil)

    // 通过一个属性字符串创建 
    public init(attributedString attrStr: NSAttributedString)

    
    @available(iOS 4.0, *)
    open func enumerateAttributes(in enumerationRange: NSRange, options opts: NSAttributedString.EnumerationOptions = [], using block: ([String : Any], NSRange, UnsafeMutablePointer<ObjCBool>) -> Swift.Void)

    @available(iOS 4.0, *)
    open func enumerateAttribute(_ attrName: String, in enumerationRange: NSRange, options opts: NSAttributedString.EnumerationOptions = [], using block: (Any?, NSRange, UnsafeMutablePointer<ObjCBool>) -> Swift.Void)
}

extension NSAttributedString {

    public struct EnumerationOptions : OptionSet {

        public init(rawValue: UInt)

        public static var reverse: NSAttributedString.EnumerationOptions { get }

        public static var longestEffectiveRangeNotRequired: NSAttributedString.EnumerationOptions { get }
    }
}

@available(iOS 3.2, *)
open class NSMutableAttributedString : NSAttributedString {

    
    open func replaceCharacters(in range: NSRange, with str: String)

    open func setAttributes(_ attrs: [String : Any]?, range: NSRange)
}

extension NSMutableAttributedString {

    // 获取可变字符串
    open var mutableString: NSMutableString { get }

    
    // attribute 的操作
    open func addAttribute(_ name: String, value: Any, range: NSRange)

    open func addAttributes(_ attrs: [String : Any] = [:], range: NSRange)

    open func removeAttribute(_ name: String, range: NSRange)





    // 字符串（字符）的操作方法（增删改查）
    open func replaceCharacters(in range: NSRange, with attrString: NSAttributedString)

    open func insert(_ attrString: NSAttributedString, at loc: Int)

    open func append(_ attrString: NSAttributedString)

    open func deleteCharacters(in range: NSRange)

    open func setAttributedString(_ attrString: NSAttributedString)

    
    open func beginEditing()

    open func endEditing()
}