在用户默认情况下保存并获取自定义对象数组

Question

我的对象有以下实现

class CategoriesResponse : NSObject{

    let STATUS      = "status";
    let DATA        = "data";

    var     status : Bool;
    var     categories : Array<CategoryResponse>;


    override init () {

        status = false;
        categories = Array();

    }

    init(data : NSDictionary){

        status      = data[STATUS] as! Bool;

        if (status == true) {

            if let categoriesArray = data[DATA] as? Array<NSDictionary> {

                categories = Array();

                for anItem in categoriesArray {

                    let item: CategoryResponse = CategoryResponse.init(data: anItem);
                    categories.append(item);
                }

            } else {
                categories = Array();
            }

        } else {
            categories = Array();
        }
    }
}

和

class CategoryResponse {

    let CAT_ID              = "CatId";
    let NAME                = "Name";
    let COLOR               = "Color";
    let CAT_ICON            = "CatIcon";

    var     catId : Int
    var     name : String;
    var     color : String;
    var     catIcon : String;

    init(data : NSDictionary){


        catId       = data[CAT_ID] as! Int;
        name        = data[NAME] as! String;
        color       = data[COLOR] as! String;
        catIcon     = data[CAT_ICON] as! String;
    }

    func printObject () {

        print("----------------------------- Start Print ---------------------------")
        print("catId: " + String(catId));
        print("name: " + name);
        print("color: " + color);
        print("catIcon: " + catIcon);
        print("------------------------------- End Print ---------------------------")
    }
}

我正在尝试使用以下代码

在用户默认值中保存CategoriesResponse类型的对象

let defaults = NSUserDefaults.standardUserDefaults()
            let dataExample : NSData = NSKeyedArchiver.archivedDataWithRootObject(categories.categories)
            defaults.setObject(dataExample, forKey: CATEGORIES);

但是当它运行时它不起作用并且通过异常

任何人都可以告诉我这是什么问题吗？