我正在尝试按位置对用户的帖子进行排序并使用 PFGeopoint 和 Swift 显示距离

Posted 2023-03-10

【中文标题】我正在尝试按位置对用户的帖子进行排序并使用 PFGeopoint 和 Swift 显示距离

【英文标题】：I'm Trying to sort a user's post by location and displaying the distance using PFGeopoint and Swift

【发布时间】：2017-02-13 23:53:29

【问题描述】：

我正在尝试按距离对用户的帖子进行排序，并隐藏任何超过一定里程的帖子。我还试图在我的 UITableview 中从最近到最远进行排序：

class FindAParty:UITableViewController

    //var partyData:NSMutableArray! = NSMutableArray()
    var partyData = [PFObject]()
    //var user:NSMutableArray = NSMutableArray()

    override init(style: UITableViewStyle)
        super.init(style: style)

    

    required init?(coder aDecoder: NSCoder) 
        super.init(coder: aDecoder)
        //fatalError("init(coder:) has not been implemented")

    


    @IBAction func loadData()

        PFGeoPoint.geoPointForCurrentLocation  (geopoint, error) in

            print(geopoint)
            if let geopoint = geopoint 
                PFUser.current()?.remove(forKey: "Location")

                print ("True")
            PFUser.current()? ["Location"] = geopoint
                PFUser.current()?.saveInBackground()


             

        




        print ("Load Data went through")
        partyData.removeAll()
        print ("Remove ALL Objeccts")
        let findPartyData = PFQuery(className: "Party")

        print("PFQuery...")
        findPartyData.findObjectsInBackground 
            (objects:[PFObject]?, error:Error?)->Void in

            if error != nil 
                print(error!)
             else
                if let objects = objects 
                    self.partyData = objects.reversed()
                
                DispatchQueue.main.async 
                    self.tableView.reloadData()
                
            
        
    
    override func viewDidAppear(_ animated: Bool) 
        self.loadData()
        print("View Did Appear")
    
    override func viewDidLoad() 
        super.viewDidLoad()
        print("ViewDidLoad")
        //self.loadData()
        // 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.
    

    // #pragma mark - Table view data source
    override func numberOfSections(in tableView: UITableView) -> Int 
        return 1
    
    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int 
        return partyData.count
    


    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell 
    let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) as! FindAPartyCell

       let party = self.partyData[indexPath.row]





        cell.typeOfPartyLabel.alpha = 0
        cell.timeOfPartyLabel.alpha = 0
        cell.usernameLabel.alpha = 0
        cell.alcoholTFLabel.alpha = 0

        cell.typeOfPartyLabel.text = party.object(forKey: "partyTitle") as? String
        cell.timeOfPartyLabel.text = party.object(forKey: "partyTime") as? String
        cell.usernameLabel.text = party.object(forKey: "Usernames") as? String
        cell.alcoholTFLabel.text = party.object(forKey: "ATF") as? String

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

       /* let findUser:PFQuery = PFUser.query()!
        findUser.whereKey("objectId", equalTo: party.object(forKey: "Username")!)


        findUser.findObjectsInBackground 
            (objects:[PFObject]?, error: Error?) -> Void in // Changes NSError to Error
            if error == nil

                let user:PFUser = (objects)!.last as! PFUser
                cell.usernameLabel.text = user.username

               */ UIView.animate(withDuration: 0.5, animations: 
                    cell.typeOfPartyLabel.alpha = 1
                    cell.timeOfPartyLabel.alpha = 1
                    cell.usernameLabel.alpha = 1
                    cell.alcoholTFLabel.alpha = 1
                )
            //
        //


        return cell
    

如果可能的话，我还想显示距离。 谢谢你的建议

【参考方案1】：

您可以使用 Parse 提供的地理查询。

whereKey:nearGeoPoint 返回按距离排序的对象数组（从最近到最远）

whereKey:nearGeoPoint:withinMiles/ whereKey:nearGeoPoint:withinKilometers 使用距离（米/公里）限制结果

按“位置”查询用户（您应该考虑使用小写的属性） let query = PFUser.query()! query.whereKey("Location", nearGeoPoint: geopoint) 获取他们的帖子...（单独的帖子表？使用关系？）