Ios 如何在Swift中使用委派而不是NSNotification

我正在寻找一种解决方案，以避免在代码中使用NSNotifications。这是我的故事板摘录，用于解释我的问题：

通常涉及两类：

import UIKit

class ScanTableView: UITableViewController
{
    @IBOutlet var ScanTableView: UITableView!

    var valueCollectionView: ValueCollectionView?

    override func viewDidLoad()
    {
        super.viewDidLoad()
        self.refreshControl!.addTarget(self, action: "refresh", forControlEvents: UIControlEvents.ValueChanged)
    }

    override func didReceiveMemoryWarning()
    {
        super.didReceiveMemoryWarning()
    }

    override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int
    {
        return BluetoothManager.bluetoothManager.peripheralArray.count
    }

    override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell
    {
        let cell = ScanTableView.dequeueReusableCellWithIdentifier("scanCell",forIndexPath: indexPath)

        cell.textLabel!.text = BluetoothManager.bluetoothManager.peripheralArray[indexPath.row].name
        return cell
    }

    override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath)
    {
        BluetoothManager.bluetoothManager.connectPeripheral(indexPath.row)
    }

    func refresh()
    {
        BluetoothManager.bluetoothManager = BluetoothManager()
    }
}

 import UIKit

    class ValueCollectionView: UICollectionViewController
    {
        @IBOutlet var ValueCollectionView: UICollectionView!

        var scanTableView: ScanTableView?

        var valueCollectionViewCell: ValueCollectionViewCell = ValueCollectionViewCell()

        override func viewDidLoad()
        {
            super.viewDidLoad()
            BluetoothManager.bluetoothManager.valueCollectionView = ValueCollectionView
            self.navigationItem.hidesBackButton = true
            let disconnectButton = UIBarButtonItem(title: "Disconnect", style: UIBarButtonItemStyle.Plain, target: self, action: "disconnect:")
            self.navigationItem.leftBarButtonItem = disconnectButton;
        }

        override func didReceiveMemoryWarning()
        {
            super.didReceiveMemoryWarning()
        }

//Function to go back to the ScanTableView
//The ScanTableView should be clear after the reload
        func disconnect(sender: UIBarButtonItem)
        {
            BluetoothManager.bluetoothManager.disconnectPeripheral(BluetoothManager.bluetoothManager.selectedPeripheralIndex!)
            //Remove all Items of the TableView
            BluetoothManager.bluetoothManager.peripheralArray.removeAll()
            let switchViewController = self.navigationController?.viewControllers[1] as! ScanTableView
            self.navigationController?.popToViewController(switchViewController, animated: true)

    // This part doesn't work! The appearing TableView isn't cleared
                    scanTableView?.ScanTableView.reloadData()

        }

        override func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int
        {
            return BluetoothManager.bluetoothManager.measurementValue.count
        }

        override func collectionView(tableView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell
        {
            let cell: ValueCollectionViewCell = collectionView?.dequeueReusableCellWithReuseIdentifier("valueCell", forIndexPath: indexPath) as! ValueCollectionViewCell
            cell.ValueCollectionViewLabel.text = BluetoothManager.bluetoothManager.measurementValue[indexPath.row]
            return cell
        }
    }

ScanTableView

\

ValueCollectionView

//BluetoothManager类对我的问题不感兴趣，工作正常

扫描表视图类：

import UIKit

class ScanTableView: UITableViewController
{
    @IBOutlet var ScanTableView: UITableView!

    var valueCollectionView: ValueCollectionView?

    override func viewDidLoad()
    {
        super.viewDidLoad()
        self.refreshControl!.addTarget(self, action: "refresh", forControlEvents: UIControlEvents.ValueChanged)
    }

    override func didReceiveMemoryWarning()
    {
        super.didReceiveMemoryWarning()
    }

    override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int
    {
        return BluetoothManager.bluetoothManager.peripheralArray.count
    }

    override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell
    {
        let cell = ScanTableView.dequeueReusableCellWithIdentifier("scanCell",forIndexPath: indexPath)

        cell.textLabel!.text = BluetoothManager.bluetoothManager.peripheralArray[indexPath.row].name
        return cell
    }

    override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath)
    {
        BluetoothManager.bluetoothManager.connectPeripheral(indexPath.row)
    }

    func refresh()
    {
        BluetoothManager.bluetoothManager = BluetoothManager()
    }
}

 import UIKit

    class ValueCollectionView: UICollectionViewController
    {
        @IBOutlet var ValueCollectionView: UICollectionView!

        var scanTableView: ScanTableView?

        var valueCollectionViewCell: ValueCollectionViewCell = ValueCollectionViewCell()

        override func viewDidLoad()
        {
            super.viewDidLoad()
            BluetoothManager.bluetoothManager.valueCollectionView = ValueCollectionView
            self.navigationItem.hidesBackButton = true
            let disconnectButton = UIBarButtonItem(title: "Disconnect", style: UIBarButtonItemStyle.Plain, target: self, action: "disconnect:")
            self.navigationItem.leftBarButtonItem = disconnectButton;
        }

        override func didReceiveMemoryWarning()
        {
            super.didReceiveMemoryWarning()
        }

//Function to go back to the ScanTableView
//The ScanTableView should be clear after the reload
        func disconnect(sender: UIBarButtonItem)
        {
            BluetoothManager.bluetoothManager.disconnectPeripheral(BluetoothManager.bluetoothManager.selectedPeripheralIndex!)
            //Remove all Items of the TableView
            BluetoothManager.bluetoothManager.peripheralArray.removeAll()
            let switchViewController = self.navigationController?.viewControllers[1] as! ScanTableView
            self.navigationController?.popToViewController(switchViewController, animated: true)

    // This part doesn't work! The appearing TableView isn't cleared
                    scanTableView?.ScanTableView.reloadData()

        }

        override func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int
        {
            return BluetoothManager.bluetoothManager.measurementValue.count
        }

        override func collectionView(tableView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell
        {
            let cell: ValueCollectionViewCell = collectionView?.dequeueReusableCellWithReuseIdentifier("valueCell", forIndexPath: indexPath) as! ValueCollectionViewCell
            cell.ValueCollectionViewLabel.text = BluetoothManager.bluetoothManager.measurementValue[indexPath.row]
            return cell
        }
    }

ValueCollectionView类：

import UIKit

class ScanTableView: UITableViewController
{
    @IBOutlet var ScanTableView: UITableView!

    var valueCollectionView: ValueCollectionView?

    override func viewDidLoad()
    {
        super.viewDidLoad()
        self.refreshControl!.addTarget(self, action: "refresh", forControlEvents: UIControlEvents.ValueChanged)
    }

    override func didReceiveMemoryWarning()
    {
        super.didReceiveMemoryWarning()
    }

    override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int
    {
        return BluetoothManager.bluetoothManager.peripheralArray.count
    }

    override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell
    {
        let cell = ScanTableView.dequeueReusableCellWithIdentifier("scanCell",forIndexPath: indexPath)

        cell.textLabel!.text = BluetoothManager.bluetoothManager.peripheralArray[indexPath.row].name
        return cell
    }

    override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath)
    {
        BluetoothManager.bluetoothManager.connectPeripheral(indexPath.row)
    }

    func refresh()
    {
        BluetoothManager.bluetoothManager = BluetoothManager()
    }
}

 import UIKit

    class ValueCollectionView: UICollectionViewController
    {
        @IBOutlet var ValueCollectionView: UICollectionView!

        var scanTableView: ScanTableView?

        var valueCollectionViewCell: ValueCollectionViewCell = ValueCollectionViewCell()

        override func viewDidLoad()
        {
            super.viewDidLoad()
            BluetoothManager.bluetoothManager.valueCollectionView = ValueCollectionView
            self.navigationItem.hidesBackButton = true
            let disconnectButton = UIBarButtonItem(title: "Disconnect", style: UIBarButtonItemStyle.Plain, target: self, action: "disconnect:")
            self.navigationItem.leftBarButtonItem = disconnectButton;
        }

        override func didReceiveMemoryWarning()
        {
            super.didReceiveMemoryWarning()
        }

//Function to go back to the ScanTableView
//The ScanTableView should be clear after the reload
        func disconnect(sender: UIBarButtonItem)
        {
            BluetoothManager.bluetoothManager.disconnectPeripheral(BluetoothManager.bluetoothManager.selectedPeripheralIndex!)
            //Remove all Items of the TableView
            BluetoothManager.bluetoothManager.peripheralArray.removeAll()
            let switchViewController = self.navigationController?.viewControllers[1] as! ScanTableView
            self.navigationController?.popToViewController(switchViewController, animated: true)

    // This part doesn't work! The appearing TableView isn't cleared
                    scanTableView?.ScanTableView.reloadData()

        }

        override func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int
        {
            return BluetoothManager.bluetoothManager.measurementValue.count
        }

        override func collectionView(tableView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell
        {
            let cell: ValueCollectionViewCell = collectionView?.dequeueReusableCellWithReuseIdentifier("valueCell", forIndexPath: indexPath) as! ValueCollectionViewCell
            cell.ValueCollectionViewLabel.text = BluetoothManager.bluetoothManager.measurementValue[indexPath.row]
            return cell
        }
    }

问题：

import UIKit

class ScanTableView: UITableViewController
{
    @IBOutlet var ScanTableView: UITableView!

    var valueCollectionView: ValueCollectionView?

    override func viewDidLoad()
    {
        super.viewDidLoad()
        self.refreshControl!.addTarget(self, action: "refresh", forControlEvents: UIControlEvents.ValueChanged)
    }

    override func didReceiveMemoryWarning()
    {
        super.didReceiveMemoryWarning()
    }

    override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int
    {
        return BluetoothManager.bluetoothManager.peripheralArray.count
    }

    override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell
    {
        let cell = ScanTableView.dequeueReusableCellWithIdentifier("scanCell",forIndexPath: indexPath)

        cell.textLabel!.text = BluetoothManager.bluetoothManager.peripheralArray[indexPath.row].name
        return cell
    }

    override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath)
    {
        BluetoothManager.bluetoothManager.connectPeripheral(indexPath.row)
    }

    func refresh()
    {
        BluetoothManager.bluetoothManager = BluetoothManager()
    }
}

 import UIKit

    class ValueCollectionView: UICollectionViewController
    {
        @IBOutlet var ValueCollectionView: UICollectionView!

        var scanTableView: ScanTableView?

        var valueCollectionViewCell: ValueCollectionViewCell = ValueCollectionViewCell()

        override func viewDidLoad()
        {
            super.viewDidLoad()
            BluetoothManager.bluetoothManager.valueCollectionView = ValueCollectionView
            self.navigationItem.hidesBackButton = true
            let disconnectButton = UIBarButtonItem(title: "Disconnect", style: UIBarButtonItemStyle.Plain, target: self, action: "disconnect:")
            self.navigationItem.leftBarButtonItem = disconnectButton;
        }

        override func didReceiveMemoryWarning()
        {
            super.didReceiveMemoryWarning()
        }

//Function to go back to the ScanTableView
//The ScanTableView should be clear after the reload
        func disconnect(sender: UIBarButtonItem)
        {
            BluetoothManager.bluetoothManager.disconnectPeripheral(BluetoothManager.bluetoothManager.selectedPeripheralIndex!)
            //Remove all Items of the TableView
            BluetoothManager.bluetoothManager.peripheralArray.removeAll()
            let switchViewController = self.navigationController?.viewControllers[1] as! ScanTableView
            self.navigationController?.popToViewController(switchViewController, animated: true)

    // This part doesn't work! The appearing TableView isn't cleared
                    scanTableView?.ScanTableView.reloadData()

        }

        override func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int
        {
            return BluetoothManager.bluetoothManager.measurementValue.count
        }

        override func collectionView(tableView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell
        {
            let cell: ValueCollectionViewCell = collectionView?.dequeueReusableCellWithReuseIdentifier("valueCell", forIndexPath: indexPath) as! ValueCollectionViewCell
            cell.ValueCollectionViewLabel.text = BluetoothManager.bluetoothManager.measurementValue[indexPath.row]
            return cell
        }
    }

为什么我无法在标记的部分重新加载ScanTableView？通话后没有任何事情发生：

scanTableView?.ScanTableView.reloadData()

---

在代码中，任何时候都没有将任何对象设置为ValueCollectionView的

scanTableView

。因此，它是

nil

，并且

reloadData（）

行没有效果

---

换句话说，如果要使用委托，必须有一个委托。

为什么要显示所有代码，问题是什么？只是你不知道什么是授权，你想知道吗？现在更清楚了吗？好的，我怎么解决这个问题？我试图将“valueCollectionView？.scanTableView=scanTableView”添加到我的scanTableView的viewDidLoad函数中。但我总是会遇到错误。错误是：“无法将“UITableView！”类型的值分配给“ScanTableView”类型的值。”“ScanTableView是视图控制器类型，而不是表视图类型。委托必须是ScanTableView本身。