问使用textfield委托方法Swift获取行和节

EN

//  Created by Duncan Champney on 12/23/16.
//  Copyright © 2016-2017 Duncan Champney.
//  May be used freely in for any purpose as long as this copyright
//  notice is included.
//
import UIKit

public extension UITableView {
    
    /**
     This method returns the indexPath of the cell that contains the specified view
     - Parameter view: The view to find.
     - Returns: The indexPath of the cell containing the view, or nil if it can't be found
     */
    
    func indexPathForView(_ view: UIView) -> IndexPath? {
        let center = view.center
        
        //The center of the view is a better point to use, but we can only use it if the view has a superview
        guard let superview = view.superview else {
            //The view we were passed does not have a valid superview.
            //Use the view's bounds.origin and convert from the view's coordinate system
            let origin = self.convert(view.bounds.origin, from: view)
            let indexPath = self.indexPathForRow(at: origin)
            return indexPath
        }
        let viewCenter = self.convert(center, from: superview)
        let indexPath = self.indexPathForRow(at: viewCenter)
        return indexPath
    }
}

func textFieldDidEndEditing(_ textField: UITextField) {
    if let indexPath = tableView.indexPathForView(textField) {
        let row = indexPath.row
        let section = indexPath.section
    } else {
        // Can't find the IndexPath. Handle error
    }
}

class ViewController: UIViewController {
    lazy var tableView: UITableView = {
        let tableView = UITableView(frame: .zero, style: .insetGrouped)
        tableView.translatesAutoresizingMaskIntoConstraints = false
        tableView.register(SomeCell.self, forCellReuseIdentifier: "SomeCell")
        tableView.backgroundColor = .systemBackground
        tableView.delegate = self
        tableView.dataSource = self
        tableView.estimatedRowHeight = 44
        tableView.rowHeight = UITableView.automaticDimension
        return tableView
    }()

    override func viewDidLoad() {
        super.viewDidLoad()
        view.addSubview(tableView)
        tableView.snp.makeConstraints{ (make) in
            make.edges.equalTo(view.safeAreaLayoutGuide)
        }
    }
}

extension ViewController: UITableViewDataSource, UITableViewDelegate {
    func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return 10
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "SomeCell", for: indexPath) as! SomeCell
        cell.delegate = self
        return cell
    }
}

extension ViewController: SomeCellDelegate {
    func someCellTextChanged(_ cell: SomeCell, text: String?) {
        guard let indexPath = tableView.indexPath(for: cell) else { fatalError("Oh no") }
        print("someCellTextChanged at indexPath: \(indexPath) to \(text ?? "")")
    }
}

protocol SomeCellDelegate: AnyObject {
    func someCellTextChanged(_ cell: SomeCell, text: String?)
}

class SomeCell: UITableViewCell, UITextFieldDelegate {
    weak var delegate: SomeCellDelegate?

    lazy var textField: UITextField = {
        let textField = UITextField()
        textField.translatesAutoresizingMaskIntoConstraints = false
        textField.backgroundColor = .systemPurple
        return textField
    }()

    override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
        super.init(style: style, reuseIdentifier: reuseIdentifier)

        contentView.addSubview(textField)
        textField.delegate = self
        textField.snp.makeConstraints { make in
            make.edges.equalTo(contentView.layoutMarginsGuide)
        }

        backgroundColor = .systemMint
        contentView.backgroundColor = .systemPink
    }

    required init?(coder: NSCoder) {
        fatalError("nope")
    }

    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        textField.resignFirstResponder()
        return true
    }
    func textFieldDidEndEditing(_ textField: UITextField) {
        delegate?.someCellTextChanged(self, text: textField.text)
    }
}