ios - 从 [String :AnyObject] to unrelated type NSMutableDictionary always fails Warning

Question

代码可以正常工作，但我如何消除这个每次都不断出现的警告？

let parentView = self.parentViewController as! SBProfileViewController
parentView.savedDetailsModel = SBSavedUserModel(data:responseObject["data"].dictionaryObject! as! NSMutableDictionary)

cast from '[String:AnyObject]' to unrelated type 'NSMutableDictionary' always fails Warning

SavedUserModel 存储保存的信息:--

class SBSavedUserModel : NSObject { 
var userId : String!
var firstName : String!
var lastName : String!
var imageBase64 : String!

required init ( data : NSMutableDictionary) {
    self.userId =  data.objectForKey("userId") as! String
    self.firstName = data.objectForKey("fName") as! String
    self.lastName = data.objectForKey("lName") as! String
    self.imageBase64 = data.objectForKey("image") as! String
}

Answer 1

尝试替换

responseObject["data"].dictionaryObject!作为! NSMutableDictionary

用这个:

NSMutableDictionary(dictionary: responseObject["data"].dictionaryObject!)

你可以轻松地将它转换成一个 NSDictionary，但是由于某些原因，当你想要一个 NSMutableDictionary 时，你必须用 NSMutableDictionary(dictionary:)

初始化一个新的

编辑:请参阅@Tommy 对此问题的评论，了解为什么这是必要的。