迅速。 错误：无法将“[AnyObject?]”类型的值转换为预期的参数类型“AnyObject?”

Question

Trying to save data offline. But, getting the error of Cannot convert value of type '[AnyObject?]' to expected argument type 'AnyObject?'. Couldn't figure out how to convert AnyObject array to String array. Thank you for you guys help.

// outside the function
var senderArray = [String]()
var messageArray = [String?]()
var photoArray = [UIImage?]()
// func.........
    query.whereKey("downloaded", equalTo: false)
    query.findObjectsInBackgroundWithBlock { (objects: [PFObject]?, error: NSError?) -> Void in
        if error != nil {
        }

        for object in objects! {
            self.senderArray.append(object.objectForKey("sender") as! String)
            self.messageArray.append(object.objectForKey("message") as? String)
            if object.objectForKey("photo") != nil {
                if let converyPFFile = object.objectForKey("photo") as? PFFile{
                    let temp = try! converyPFFile.getData()
                    let image = UIImage(data: temp)
                    self.photoArray.append(image)
                }
            } else {
                self.photoArray.append(nil)
            }
        }

        var tempLocalNameArray = [AnyObject?]()
        var tempLocalMessageArray = [AnyObject?]()
        var tempLocalImageArray = [AnyObject?]()

        if NSUserDefaults.standardUserDefaults().arrayForKey("nameArray") != nil {
            tempLocalNameArray = NSUserDefaults.standardUserDefaults().arrayForKey("nameArray")!
            tempLocalMessageArray = NSUserDefaults.standardUserDefaults().arrayForKey("messageArray")!
            tempLocalImageArray = NSUserDefaults.standardUserDefaults().arrayForKey("imageArray")!
        }

        for i in 0 ..< self.senderArray.count {
            tempLocalNameArray.append(self.senderArray[i])
            tempLocalMessageArray.append(self.messageArray[i])
            tempLocalImageArray.append(self.photoArray[i])
        }
        // error highlighted
        NSUserDefaults.standardUserDefaults().setObject(tempLocalNameArray, forKey: "nameArray")
        // error highlighted
        NSUserDefaults.standardUserDefaults().setObject(tempLocalMessageArray, forKey: "messageArray")
        // error highlighted
        NSUserDefaults.standardUserDefaults().setObject(tempLocalImageArray, forKey: "imageArray")

        self.loadChat()
     }

Answer 1

You are trying to store images with NSUserDefaults. But NSUserDefaults does not store any kind of data. Please read the documentation :

The value parameter can be only property list objects: NSData, NSString, NSNumber, NSDate, NSArray, or NSDictionary. For NSArray and NSDictionary objects, their contents must be property list objects.

This article may help you.