Question

因为标题说我试图在点击一个单元格时显示详细视图。我的问题在于我正在使用的prepareForSegue函数。我没有收到任何错误但是当我在模拟器上运行时，我得到了一个未被捕获的异常。它出现在prepareForSegue函数的最后一行。它找到的名称为零，我不确定为什么变量为零。任何帮助将不胜感激。

更新：未被捕获的错误不再是问题。现在，在点击单元格时，数据不会显示。

class LocalPostsTableViewController: UITableViewController, UINavigationBarDelegate {

var currentIndexPath: NSIndexPath?

func displayAlert(title: String, message: String) {
    var alert = UIAlertController(title: title, message: message, preferredStyle: UIAlertControllerStyle.Alert)
    alert.addAction(UIAlertAction(title: "Ok", style: .Default, handler: { (action) -> Void in
    }))
    self.presentViewController(alert, animated: true, completion: nil)
}

var names = [String]()
var locations = [String]()
var dates = [String]()
var imageFiles = [PFFile]()
var abouts = [String]()

override func viewDidLoad() {
    super.viewDidLoad()

    PFGeoPoint.geoPointForCurrentLocationInBackground { (geoPoint, error) -> Void in
        if let geoPoint = geoPoint {
            PFUser.currentUser()?["location"] = geoPoint
            PFUser.currentUser()?.saveInBackground()

    var getLocalPostsQuery = PFQuery(className: "publicPosts")
    if let latitude = PFUser.currentUser()!["location"].latitude {
        if let longitude = PFUser.currentUser()!["location"].longitude {
    getLocalPostsQuery.whereKey("searchLocation", withinGeoBoxFromSouthwest: PFGeoPoint(latitude: latitude - 0.5, longitude: longitude - 0.5), toNortheast:  PFGeoPoint(latitude: latitude + 0.5, longitude: longitude + 0.5))
    getLocalPostsQuery.findObjectsInBackgroundWithBlock { (objects, error) -> Void in
        if let objects = objects {

                self.names.removeAll(keepCapacity: true)
                self.locations.removeAll(keepCapacity: true)
                self.abouts.removeAll(keepCapacity: true)
                self.dates.removeAll(keepCapacity: true)
                self.imageFiles.removeAll(keepCapacity: true)

                for object in objects {

                    self.names.append(object["name"] as! String)
                    self.locations.append(object["location"] as! String)
                    self.dates.append(object["date"] as! String)
                    self.abouts.append(object["about"] as! String)
                    self.imageFiles.append(object["imageFile"] as! PFFile)
                    self.tableView.reloadData()
                            }
                        }
                    }
                }
            }
        }
    }
}

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 Incomplete implementation, return the number of sections
    return 1
}

override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    // #warning Incomplete implementation, return the number of rows
    return names.count
}


override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    let LECell = tableView.dequeueReusableCellWithIdentifier("LocalPostsCell", forIndexPath: indexPath) as! LocalPostsTableViewCell

    imageFiles[indexPath.row].getDataInBackgroundWithBlock { (data, error) -> Void in
        if let downloadedImage = UIImage(data: data!) {

            LECell.postImage.image = downloadedImage
        }
    }


    LECell.postName.text = names[indexPath.row]
    LECell.postLocation.text = locations[indexPath.row]
    LECell.postDate.text = dates[indexPath.row]

    return LECell
}

let localPostsDetailSegue = "showLocalPostsDetailView"

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    if segue.identifier == localPostsDetailSegue {
        let detailScene = segue.destinationViewController as! LocalPostsDetailViewController

        if let indexPath = self.tableView.indexPathForSelectedRow {
            let row = Int(indexPath.row)
            detailScene.postName?.text = names[row]
        }
    }
}
}

Answer 1

您应该将字符串传递给下一个控制器，并将此文本设置为下一屏幕的viewDidLoad中的标签。

定义：

var postName: String!

LocalPostsDetailViewController

中的

并在prepareForSegue

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == localPostsDetailSegue {
    let detailScene = segue.destinationViewController as! LocalPostsDetailViewController

    if let indexPath = self.tableView.indexPathForSelectedRow {
        let row = Int(indexPath.row)
        detailScene.postName = names[row]
    }
}

}

在viewDidLoad的{{1}}设置它：

LocalPostsDetailViewController

Answer 2

无需使用didSelectRowAtIndexPath。只需使用标识符定义storyBoard中的segue，以下内容应该有效：

let localPostsDetailSegue = "showLocalPostsDetailView"  

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
        if segue.identifier == localPostsDetailSegue {
            let detailScene = segue.destinationViewController as! LocalPostsDetailViewController

            if let indexPath = self.tableView.indexPathForSelectedRow {
                let row = Int(indexPath.row)
                detailScene.postName?.text = names[row]
            }
        }
    }

单元格轻敲Swift Parse

2 个答案: