类型没有成员名称“objectForKey”并且使用未解析的标识符

Posted 2023-02-24

【中文标题】类型没有成员名称“objectForKey”并且使用未解析的标识符

【英文标题】：Type does not have a member names 'objectForKey' and use of unresolved identifiers

【发布时间】：2015-03-08 15:07:12

【问题描述】：

使用 swift/parse 尝试在下表视图控制器中填充自定义单元格。 pfquery 代码似乎运行良好，但是当我尝试使用数据来填充 cell.something.text 应该返回的结果时，我收到错误，表明该类型没有名为“objectForKey”的成员并使用未解析的标识符。这些错误都具体发生在覆盖 func tableView(tableView..cellForRowAtIndexPath....

import UIKit

class TimeLineTableViewController: UITableViewController 





    var timelineData:NSMutableArray = NSMutableArray()

    override init(style: UITableViewStyle) 
        super.init(style: style)
        // Custom initialization
    

    required init(coder aDecoder: NSCoder) 
        super.init(coder: aDecoder)
    



    func loadData()
        timelineData.removeAllObjects()
        //let predicate = NSPredicate(format: PFuser = PFUser.current)
        var findTimelineData:PFQuery = PFQuery(className: "event")
        //findTimelineData.whereKey(PFUser.self, equalTo: PFUser.currentUser())
        findTimelineData.findObjectsInBackgroundWithBlock
            (objects: [AnyObject]!, error: NSError!) -> Void in
            if error == nil 

                // The find succeeded.
                println("Successfully retrieved \(objects.count) scores.")
                // Do something with the found objects
                if let objects = objects as? [PFObject] 
                    for object in objects 
                        self.timelineData.addObject(object)
                        println(object.objectId)
                    
                    let array:NSArray = self.timelineData.reverseObjectEnumerator().allObjects
                    self.timelineData = array as NSMutableArray
                    self.tableView.reloadData()
                
             else 
                // Log details of the failure
                println("Error: \(error) \(error.userInfo!)")

            
        

    

    override func viewDidLoad() 
        super.viewDidLoad()

        // Uncomment the following line to preserve selection between presentations
        // self.clearsSelectionOnViewWillAppear = false

        // Uncomment the following line to display an Edit button in the navigation bar for this view controller.
        // self.navigationItem.rightBarButtonItem = self.editButtonItem()
    

    override func didReceiveMemoryWarning() 
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    

    // MARK: - Table view data source

    override func numberOfSectionsInTableView(tableView: UITableView) -> Int 
        // #warning Potentially incomplete method implementation.
        // Return the number of sections.
        return 1
    

    override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int 
        // #warning Incomplete method implementation.
        // Return the number of rows in the section.
        return timelineData.count
    


    override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell 
        let cell:TimeLineTableViewCell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as TimeLineTableViewCell

        let event:PFObject = self.timelineData.objectAtIndex(indexPath.row) as PFObject

        cell.eventLabel.alpha = 0
        cell.dateLabel.alpha = 0
        cell.minutesLabel.alpha = 0

        cell.eventLabel.text = Category.objectForKey("content") as String
        cell.minutesLabel.text = duration.objectForKey


        var dataFormatter:NSDateFormatter = NSDateFormatter()
        dataFormatter.dateFormat = "yyyy-MM-dd HH:mm"
        cell.dateLabel.text = dataFormatter.stringFromDate(category.createdAt)

        var findRecorder:PFQuery = PFUser.query()
        findRecorder.whereKey("objectId", equalTo: event.objectForKey(user).objectId)

        findRecorder.findObjectsInBackgroundWithBlock
            (objects:[AnyObject]!, error:NSError!)->Void in
            if error == nil
                let user:PFUser = (objects as NSArray).lastObject as PFUser


                UIView.animateWithDuration(0.5, animations: 
                    cell.eventLabel.alpha = 1
                    cell.dateLabel.alpha = 1
                    cell.minutesLabel.alpha = 1
                )
            
        


        return cell
    

    /*
    // Override to support conditional editing of the table view.
    override func tableView(tableView: UITableView, canEditRowAtIndexPath indexPath: NSIndexPath) -> Bool 
        // Return NO if you do not want the specified item to be editable.
        return true
    
    */

    /*
    // Override to support editing the table view.
    override func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) 
        if editingStyle == .Delete 
            // Delete the row from the data source
            tableView.deleteRowsAtIndexPaths([indexPath], withRowAnimation: .Fade)
         else if editingStyle == .Insert 
            // Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view
            
    
    */

    /*
    // Override to support rearranging the table view.
    override func tableView(tableView: UITableView, moveRowAtIndexPath fromIndexPath: NSIndexPath, toIndexPath: NSIndexPath) 

    
    */

    /*
    // Override to support conditional rearranging of the table view.
    override func tableView(tableView: UITableView, canMoveRowAtIndexPath indexPath: NSIndexPath) -> Bool 
        // Return NO if you do not want the item to be re-orderable.
        return true
    
    */

    /*
    // MARK: - Navigation

    // In a storyboard-based application, you will often want to do a little preparation before navigation
    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) 
        // Get the new view controller using [segue destinationViewController].
        // Pass the selected object to the new view controller.
    
    */

【问题讨论】：

您的代码似乎无效，未定义 duration 并且在尝试使用 objectForKey 时未发送任何参数

【参考方案1】：

您的问题是您使用的变量没有在代码中的任何位置初始化：

cell.minutesLabel.text = duration.objectForKey
                            ^
cell.dateLabel.text = dataFormatter.stringFromDate(category.createdAt)
                                                      ^

您永远不会在代码中初始化 duration 或 category。所以你不能访问它。您首先需要对其进行初始化。

我也不确定，但看起来你没有导入 Parse 框架（也许你做了，但它不在你提供的代码中）

所以你需要先导入它：

import Parse

【讨论】：

感谢您的回复并了解您的观点。我是 Xcode 的新手并使用解析，在解析中找不到关于如何启动我认为是 PFObject 的单个变量的文档。对此有什么建议，你会建议代码是什么样的？

我试过了：var category = PFObject(className:"Event") - 没有成功。