Firebase 数据未显示在 TableView 中

Question

所以基本上我想从 Firebase 获取数据并将其放在 tableView 中，然后当一个单元格被删除时，我想从 firebase 和 table view 中删除数据......但是使用我的代码，数据甚至不是出现在 TableView 中，我真的不知道出了什么问题......？

如果有帮助，这是我的数据库结构： Structure

我将数据放入 Courses 中，然后放入包含 CourseName、AmountOfHoles 和 AdditionalDate 的 childByAutoId，然后将其返回到快照中，将快照存储在名为 course 的数组中，然后在 cellForRowAtIndexPath 中获取单元格的变量，但不知何故单元格是没有显示在 tableView 上...然后我会删除 commitEditingStyle 中的单元格和数据，但它甚至没有到达那个，因为单元格没有显示...

我是 StackOverflow 的新手，所以如果有什么看起来愚蠢或错误的地方，请见谅......不要费心告诉我......

class CoursesViewController: UITableViewController {

  var ref = FIRDatabaseReference.init()
  override func viewDidLoad() {

  ref = FIRDatabase.database().reference()

  tableView.allowsMultipleSelectionDuringEditing = false


  //let a = ref.childByAutoId()
  //a.setValue("hi")

  }

  var courses: [FIRDataSnapshot]! = []

  override func viewDidAppear(animated: Bool) {
  super.viewDidAppear(animated)

  let CoursesRef = ref.child("Courses")

  CoursesRef.observeEventType(.ChildAdded, withBlock: { snapshpt in

  self.courses.append(snapshpt)


  })


  }

  override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
  return self.courses.count
  }


  override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) ->
  UITableViewCell {

  let cell: UITableViewCell! = self.tableView .dequeueReusableCellWithIdentifier("ItemCell", forIndexPath: indexPath)


  let courseSnap: FIRDataSnapshot! = self.courses[indexPath.row]

  let course = courseSnap.value

  let coursename = course?.objectForKey("CourseName") as! String
  let amountofholes = course?.objectForKey("AmountOfHoles") as! String
  let addeddate = course?.objectForKey("AddedDate") as! String

  cell.textLabel?.text = coursename + " " + amountofholes + " Holes"
  cell.detailTextLabel?.text = addeddate

  return cell

  }

  override func tableView(tableView: UITableView, canEditRowAtIndexPath indexPath: NSIndexPath) -> Bool {
  return true
  }

  override func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {
  if editingStyle == .Delete {

  // Find the snapshot and remove the value
  let courseitem = courses[indexPath.row]

  courseitem.ref.removeValue()


  }
  }

  @IBAction func addButtonDidTouch(sender: AnyObject) {


  // Alert View for input

  let alert = UIAlertController(title: "Course Item",message: "Add Course",preferredStyle: .Alert)

  let saveAction = UIAlertAction(title: "Save", style: .Default) { (action: UIAlertAction) -> Void in

  //Get Date String
  let date = NSDate()
  print(date)

  let dateFormatter = NSDateFormatter()
  dateFormatter.dateFormat = "dd-MM-yyyy 'at' HH:mm"
  let dateString = dateFormatter.stringFromDate(date)
  print(dateString)
  //
  let courseField = alert.textFields![0]
  let holesField = alert.textFields![1]





  let Courses = self.ref.child("Courses").childByAutoId()

  let course = ["AddedDate": dateString as AnyObject,
  "CourseName": courseField.text as! AnyObject,
  "AmountOfHoles": holesField.text as! AnyObject]

  Courses.setValue(course)


  }


  //Cancel
  let cancelAction = UIAlertAction(title: "Cancel", style: .Default) { (action: UIAlertAction) -> Void in
  }

  //TextField placeholder in alert
  alert.addTextFieldWithConfigurationHandler {
  (courseField: UITextField!) -> Void in

  courseField.placeholder = "Course Name"
  }
  alert.addTextFieldWithConfigurationHandler {
  (holesField: UITextField!) -> Void in

  holesField.placeholder = "Holes (6/9/18)"
  }

  //Add alert
  alert.addAction(saveAction)
  alert.addAction(cancelAction)

  presentViewController(alert, animated: true, completion: nil)

  }


}

Answer 1

发现快照后，您必须插入代码！

我认为你可以这样：

CoursesRef.observeEventType(.ChildAdded, withBlock: { snapshot in
  self.courses.append(snapshot)
  self.yourTable.insertRowsAtIndexPaths([NSIndexPath(forRow: self.courses.count-1, inSection: 0)], withRowAnimation: .Bottom)
          })

Answer 2

检查此代码

override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
if(self.courses.count > 0){
 tablecount = self.courses.count
} else {

 tablecount = 0
 self.table.reloaddata()
}
return tablecount
}