Firebase 与 Swift 3.0 UITableView

Posted 2023-03-04

【中文标题】Firebase 与 Swift 3.0 UITableView

【英文标题】：Firebase with Swift 3.0 UITableView

【发布时间】：2016-09-23 06:02:01

【问题描述】：

我搞砸了。我升级到 Swift 3.0 没有进行备份现在我的表格视图没有加载我知道它从 Firebase 中提取数据但表格视图没有加载。我在更新之前正在加载，但现在没有运气。

import UIKit

import Firebase

class ActiveCallsTableViewController: UITableViewController 
let cellId = "callCell"
var users = [User]()
var unAcceptedUsers = [User]()
var enRoute = [User]()
var onSite = [User]()

var isFiltered = Bool()
let section = ["Unaccepted", "Enroute", "Onsite"]




override func viewDidLoad() 
    super.viewDidLoad()

    navigationItem.leftBarButtonItem = UIBarButtonItem(title: "Cancel", style: .plain, target: self, action: #selector(handleCancel))

    tableView.register(UserCell.self, forCellReuseIdentifier: cellId)


   fetchUser()


 func tableView(tableView: UITableView, titleForHeaderInSection section: Int) -> String? 
    print("titleForHeader")
    return self.section[section]




func numberOfSectionsInTableView(tableView: UITableView) -> Int 

    return 3



/// Returns the amount of minutes from another date

func fetchUser() 

    print("This is fetchUser")

    FIRDatabase.database().reference().child("Calls").observe(.childAdded, with:  (snapshot) in

        if let dictionary = snapshot.value as? [String: AnyObject]
            let user = User()


            user.setValuesForKeys(dictionary)
            self.users.append(user)



            if user.Job_Status == "Unaccepted" 
                self.isFiltered = true
                self.unAcceptedUsers.append(user)
                 print("\(user.Name) True")
            else if user.Job_Status == "Enroute"
                self.isFiltered = false
                self.enRoute.append(user)
                print("\(user.Name) False")
            else
                self.onSite.append(user)
            


            //print(self.user)
            //DispatchQueue.main.asynchronously(execute: self.tableView.reloadData())
             DispatchQueue.main.async (execute:  self.tableView.reloadData()

                print("Later in fetchUser")
            )


        

        , withCancel: nil)




func handleCancel() 
    dismiss(animated: true, completion: nil)

 func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int 


    //var rowCount: Int

print(" This is numbers Of Rows")
if section == 0 
        //rowCount = unAcceptedUsers.count
        print(unAcceptedUsers.count)
        return unAcceptedUsers.count

    
    else if section == 1
        return enRoute.count
        //rowCount = enRoute.count

    else 
        return onSite.count
    

   //return rowCount


func userForIndexPath(indexPath: NSIndexPath) -> User 
    if indexPath.section == 0 
        // print(unAcceptedUsers)
        return unAcceptedUsers[indexPath.row]

    
        print(enRoute)
        return unAcceptedUsers[indexPath.row]



 func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell 
    //print("Call Cell")
    //let cell = UITableViewCell(style: .Subtitle, reuseIdentifier: cellId)

    print("CellForRow")

    let cell = tableView.dequeueReusableCell(withIdentifier: cellId, for: indexPath as IndexPath)
    let user:User
    //let user = userForIndexPath(indexPath)

    if indexPath.section == 0 
        user = unAcceptedUsers[indexPath.row]
    else if indexPath.section == 1
        user = enRoute[indexPath.row]
    else
        user = onSite[indexPath.row]
    

    let dateFormatter = DateFormatter()
    dateFormatter.timeStyle = .short
    let date3 = dateFormatter.date(from: user.Time_Logged!)
    print("THE TIME IS \(date3)")

   let elapesedTime = NSDate().timeIntervalSince(date3!)
    //let minutesPassed = (elapesedTime / 3600)

    //let dateMinutes = NSDate().timeIntervalSinceReferenceDate (date3)

   // let calcendar = NSCalendar.currentCalendar()
    //let dateComponents = calcendar.components(NSCalendarUnit.Minute, fromDate: date3!, toDate: NSDate(), options: nil)
    //let minutesPassed = dateComponents
    print ("THE TIME IS \(elapesedTime)")

    let duration = Int(elapesedTime)
    let minutesLogged = String(duration)
   print(duration)


    //let user = users[indexPath.row]
    cell.textLabel?.text = user.Name
    cell.detailTextLabel?.text = minutesLogged
    //print(user.Adress)

    return cell


//var valueToPass:String!
var valueToPass:String!
//var productsValue = [unAcceptedCallDataVie]]

func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) 


    tableView.deselectRow(at: indexPath as IndexPath, animated: true)

    let callInfoView:UIViewController = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "Callinfo") as UIViewController
    let unAcceptedView:UIViewController = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "unAcceptedCall") as UIViewController

    let currentCell = tableView.cellForRow(at: indexPath as IndexPath) as UITableViewCell!; 

    if indexPath.section == 0 
        valueToPass = currentCell?.textLabel!.text
        //valueToPass = currentCell2
        performSegue(withIdentifier: "passData", sender: self)
        self.present(unAcceptedView, animated: true, completion: nil)

        //print(valueToPass)
    else if indexPath.section == 1
        self.present(callInfoView, animated: true, completion: nil)
        print("Enroute")
    else 
        self.present(callInfoView, animated: true, completion: nil)
        print("Onsite")
    
   // print(user.Adress)



 func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) 
    if (segue.identifier == "passData") 
        //let user:User
        // initialize new view controller and cast it as your view controller
        let viewController = segue.destination as! unAcceptedCallDataView

        // your new view controller should have property that will store passed value
        //var passedValue = viewController.nameLable.text
        //print(user.Adress)
        viewController.LableText = valueToPass

    
class UserCell: UITableViewCell 
override init(style: UITableViewCellStyle, reuseIdentifier: String?) 
    super.init(style: .subtitle, reuseIdentifier: reuseIdentifier)

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

`

【问题讨论】：

我发现了问题。当我从 Swift 2.2 迁移到 3.0 时，我只是让软件“修复”代码，但它做得很糟糕。我找到了正确的函数调用并替换了它。它有效，但我现在有 2 个不同的部分。

【参考方案1】：

尝试替换：-

 DispatchQueue.main.async (execute:...

收件人

    DispatchQueue.global(qos: .background).async 
    self.tableView.reloadData()

    DispatchQueue.main.async 
       self.tableView.reloadData()