[__NSCFArray insertObject:atIndex:]:发送到不可变对象的mutating方法'

时间:2015-12-01 05:17:47

标签: ios nsmutablearray immutability mutable swift2.1

IDK正在发生什么。我只是在我的数组中添加一个值。

以下是代码:

dispatch_async(dispatch_get_main_queue(), { () -> Void in
    let requestedURL = NSString(string: url_to_req)
    print(requestedURL.substringFromIndex(36))
    if requestedURL.substringFromIndex(36) == "forum"{
        returnValue = (parseJSON["_id"] as? String)!
        print("Here is id of posted question: '\(returnValue)'")
        if (NSUserDefaults.standardUserDefaults().objectForKey("PostedQuesIds") != nil){
            self.postedQuestionIds = NSUserDefaults.standardUserDefaults().objectForKey("PostedQuesIds") as? NSMutableArray
        }

        print("Total count of array '\(self.postedQuestionIds)")

        self.postedQuestionIds?.addObject(returnValue)// overhere my app gets a crash
        // self.postedQuestionIds = NSMutableArray(object: returnValue)
        NSUserDefaults.standardUserDefaults().setObject(self.postedQuestionIds, forKey: "PostedQuesIds")
        NSUserDefaults.standardUserDefaults().synchronize()                            
    }
})

对于疑惑,我也试过下面的代码,就好像我已经忘记了关于nsmutablearray的事情

var name = "abc"
let firstname = "dd"
let lastname = "zz"

let arr:NSMutableArray? = NSMutableArray()

arr?.addObject(name)
name = "ABC"

arr?.removeObjectAtIndex(0)
arr?.addObject(firstname)
arr?.addObject(lastname)
arr?.addObject(name)

print("Here is complete array '\(arr)'")

这很好用。请帮助我看起来我错过了什么,无法找到它们。您的努力将受到高度赞赏。

1 个答案:

答案 0 :(得分:2)

如果从NSUserDefaults中检索数组,它似乎变为不可变的数组。试试这个。

let array = NSUserDefaults.standardUserDefaults().objectForKey("PostedQuesIds") as! NSArray
self.postedQuestionIds = NSMutableArray(array: array)