NSCoding encodeObject错误

类的事件：NSObject的，NSCoding {

// MARK: Properties 
var name: String 
var created_at: String 
var stands:[Stand?] 

// MARK: Archiving Paths 

static let DocumentsDirectory = NSFileManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask).first! 
static let ArchiveURL = DocumentsDirectory.URLByAppendingPathComponent("events") 


// MARK: Types 

struct PropertyKey { 
    static let nameKey = "name" 
    static let createdAtKey = "created_at" 
    static let standsAtKey = "stands" 

} 

// MARK: Initialization 
init?(name: String, created_at: String, stands:[Stand?]) { 
    // Initialize stored properties. 
    self.name = name 
    self.created_at = created_at 
    self.stands = stands 

    super.init() 

    // Initialization should fail if there is no name or if no created_at. 
    if name.isEmpty || created_at.isEmpty { 
     return nil 
    } 
} 

// MARK: NSCoding 
func encodeWithCoder(aCoder: NSCoder) { 
    aCoder.encodeObject(name, forKey: PropertyKey.nameKey) 
    aCoder.encodeObject(created_at, forKey: PropertyKey.createdAtKey) 
    aCoder.encodeObject(stands, forKey: PropertyKey.standsAtKey) 

} 

required convenience init?(coder aDecoder: NSCoder) { 
    let name = aDecoder.decodeObjectForKey(PropertyKey.nameKey) as! String 

    let created_at = aDecoder.decodeObjectForKey(PropertyKey.createdAtKey) as! String 

    let stands = aDecoder.decodeObjectForKey(PropertyKey.standsAtKey) as! [Stand?] 

    // Must call designated initializer. 
    self.init(name: name, created_at: created_at, stands: stands) 
}

}

我有错误从 “aCoder.encodeObject（站，forKey：PropertyKey.standsAtKey）”说：“不能将[Stand？]类型的值转换为期望的参数类型'AnyObject？'”

我正在使用NSCoding来保存对象与数组空的立场，然后检索它，更新此类的事件属性（事件）

来源

2016-02-11 ankermarco

你可以添加'Stand'的代码？ – tktsubota