Question

我有一个自定义单元格，在自定义单元格中我有一个textField，我想知道如何从customCell类中创建一个协议来调用我的ViewController中的函数。我做了一些代码，但卡住了。

我的问题是，一旦我触摸textField，我想从我的ViewController调用一个函数。

class FirstViewController: UIViewController, UITableViewDelegate, UITableViewDataSource, MySearchDelegate {

var search:SearchTableViewCell = SearchTableViewCell()

    override func viewDidLoad() {
    search.delegate = self

    }
}

我的customCell类：

@objc protocol MySearchDelegate{
    optional func textFieldTouched()
}

class SearchTableViewCell: UITableViewCell, UITextFieldDelegate {

    @IBOutlet weak var searchField: UITextField!

    // this is where I declare the protocol
    var delegate:MySearchDelegate?

    func searchStart(){
        delegate?.textFieldTouched!()
    }

    override func awakeFromNib() {
        super.awakeFromNib()
        searchField.addTarget(self, action: Selector("searchStart"), forControlEvents: UIControlEvents.ValueChanged)
    }

    func searchStart(){
        delegate?.textFieldTouched()
    }

    override func setSelected(selected: Bool, animated: Bool) {
        super.setSelected(selected, animated: animated)
    }

}

Answer 1

我对swift并不擅长，所以这可能是个错误。您应该在创建单元格时分配单元格委托。

     class FirstViewController: UIViewController, UITableViewDelegate, UITableViewDataSource, MySearchDelegate {

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

                // set the delegate here not in the viewDidLoad
        cell.searchDelegate = self

                return cell
            }

            func textFieldTouched(){
                 //do what you want here
            }
}

Answer 2

修改代码以避免强引用周期并符合您的协议：

    var search:SearchTableViewCell = SearchTableViewCell()

    override func viewDidLoad() {
        search.delegate = self
    }

    func textFieldTouched() {
        println("voila")
    }

}

protocol MySearchDelegate: class {
    func textFieldTouched()
}

class SearchTableViewCell: UITableViewCell, UITextFieldDelegate {

    @IBOutlet weak var searchField: UITextField!

    // this is where I declare the protocol
    weak var delegate:MySearchDelegate?

    func searchStart(){
        delegate?.textFieldTouched()
    }

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

    override func setSelected(selected: Bool, animated: Bool) {
        super.setSelected(selected, animated: animated)
    }

}

customCell到ViewController

2 个答案: