cellForRowAtIndexPath is not being called from custom class

问题:

I'm using Xcode 7.0, Swift 2

I'm basically trying to create a custom class that will build a UITable, then in the ViewController I make a new object of the table and load it into self.view;

The problem I'm having is that the function func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell isn't being called at all from within the custom class. I've been looking for a solution for 3 days now and I've tried rebuilding the App and code several times with no luck.

Please note, if I use the same code (that is everything required to build the table; excluding init functions, etc) in the ViewController.swift file, it works fine.

I know the problem is with the cellForRowAtIndexPath function because it will not print out the statement I set in that block of code when it runs. All other functions are called, but for some reason this isn't being called. Not sure if I overlooked something here. Any help would be appreciated. Thanks in advance.

class sideTest: NSObject, UITableViewDelegate, UITableViewDataSource {       let tesTable: UITableView = UITableView()     var items: [String]?     var mView: UIView = UIView()      func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {         print("The number of rows is: \(self.items!.count)")          return self.items!.count     }      func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {          print("\nLets create some cells.")          let sCell: UITableViewCell = tableView.dequeueReusableCellWithIdentifier("cell") as UITableViewCell!          sCell.textLabel?.text = self.items![indexPath.row]         sCell.textLabel?.textColor = UIColor.darkTextColor()          return sCell     }      func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {         print("You selected cell #\(indexPath.row)!")     }      func tblSetup() {          self.tesTable.frame = CGRectMake(0, 0, 320, mView.bounds.height)         self.tesTable.delegate = self         self.tesTable.dataSource = self          self.tesTable.backgroundColor = UIColor.cyanColor()          // load cells         self.tesTable.registerClass(UITableViewCell.self, forCellReuseIdentifier: "Cell")         self.tesTable.reloadData()          print("Currenlty in tblSetup.\nCurrent rows is: \(self.items!.count)")     }      //Init      override init() {         super.init()          self.items = nil          self.tblSetup()     }      init(sourceView: UIView , itemListAsArrayString: [String]) {         super.init()          self.items = itemListAsArrayString         self.mView = sourceView          self.tblSetup()     } } 

Here is the code from ViewController.swift; Please do note that the table gets built, but the cells do not populate, even if I manually enter cell info by doing: sCell.textLabel?.text = "test cell"

class ViewController: UIViewController {        override func viewDidLoad() {         super.viewDidLoad()         // Do any additional setup after loading the view, typically from a nib.          let myTable: sideTest = sideTest(sourceView: self.view, itemListAsArrayString: ["Cell 1", "Cell 2", "Cell 3"])         self.view.addSubview(myTable.tesTable)     }      override func didReceiveMemoryWarning() {         super.didReceiveMemoryWarning()         // Dispose of any resources that can be recreated.     }    } 

Again, any help is greatly appreciated. Thanks.

回答1:

Your view controller don't have a strong reference to your sideTest var. Once your view did load finished,your sideTest is nil.Although you have a tableview(by add subview), but you no longer have a data source.

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

is called after view did load. That cause the problem.

change your view controller to:

    var tb :sideTest?   override func viewDidLoad() {     super.viewDidLoad()     let myTable: sideTest = sideTest(sourceView: self.view, itemListAsArrayString: ["Cell 1", "Cell 2", "Cell 3"])     print(myTable.tesTable.frame)     tb=myTable     self.view.addSubview(myTable.tesTable) } 

change your cellforrowatindexpath to:

  func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {      print("create cells")     var cell :UITableViewCell?      if let sCell: UITableViewCell = tableView.dequeueReusableCellWithIdentifier("cell"){        cell=sCell      }else{         cell = UITableViewCell(style: UITableViewCellStyle.Default, reuseIdentifier: "cell")      }       cell!.textLabel?.text = self.items![indexPath.row]     cell!.textLabel?.textColor = UIColor.darkTextColor()      return cell! } 

this will fix most of the problems.

回答2:

Your code:

override func viewDidLoad() {         super.viewDidLoad()         // Do any additional setup after loading the view, typically from a nib.          let myTable: sideTest = sideTest(sourceView: self.view, itemListAsArrayString: ["Cell 1", "Cell 2", "Cell 3"])         self.view.addSubview(myTable.tesTable)     } 

I would think that the myTable variable goes out of scope and is released when viewDidLoad finishes, so there is no data source or delegate after that. Did you verify that the self.view.addSubview(myTable.tesTable) retains it? Try moving declaration of myTable outside of the function level (to property level) or add a diagnostic print to deinit..

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