Question

在UIViewController中，我有一个UITableView，其中包含1个类型为TextInputTableViewCell的动态原型单元格。
在原型单元格的内容视图中，我添加了一个textField。

如何使用userInfo中的数据填充文本字段？
用户编辑后，如何获取每个textField的数据？

我已经读过SO我应该使用标签，但是其他人说这种方法容易出现bug和脆弱的。无论如何，我不知道如何使用标签或其他方法从字段中获取数据。请指教。

import Foundation
import UIKit
import Firebase

 class TextInputTableViewCell: UITableViewCell, UITextFieldDelegate{ 
      @IBOutlet weak var textField: UITextField!

     //closure when the text changes
     var textChangedCallBack: ((_ cell: TextInputTableViewCell, _ text:String) -> ())?
      //Delegate method called when the text field loses focus
     func textFieldDidEndEditing(_ textField: UITextField) {
    textChangedCallBack?(self,textField.text!)
  }
}//end of class TextInputTableViewCell



class EditProfile: UIViewController, UITableViewDelegate,UITableViewDataSource,UITextFieldDelegate {

 var dbRef:FIRDatabaseReference! //create a reference to Firebase
 var userInfo = [FireBaseData]() //this array will hold all data under userType in Firebase



@IBOutlet weak var tableView: UITableView!
@IBAction func saveToFirebase(_ sender: Any) {  

 //will post data from text fields  to firebase
}


struct Item {
    var name:String
    var editable:Bool
}

let placeHolderItems = [
    Item(name: "Name", editable: false),
    Item(name: "Phone Number", editable: true),
    Item(name: "Email", editable: true),
    Item(name: "Flat Number", editable: true),
    Item(name: "Street Address", editable: true),
    Item(name: "Postcode", editable: true)
]


override func viewDidLoad() {
    super.viewDidLoad()

   self.dbRef = FIRDatabase.database().reference().child("Cleaners")
    self.tableView.delegate = self
    self.tableView.dataSource = self
}

   override func viewWillAppear(_ animated: Bool) {
     super.viewWillAppear(true)

   //get user's profile from firebase
    self.startObservingDB { (userProfile) in

        if userProfile.count > 0 {
            self.userInfo = userProfile
             self.tableView.reloadData()
        }
    }

func numberOfSections(in tableView: UITableView) -> Int {
    return 1
}


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



func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "TextInputCell") as! TextInputTableViewCell

    cell.textField.isEnabled = placeHolderItems[indexPath.row].editable
    cell.textField.placeholder = placeHolderItems[indexPath.row].name

 //After viewWillAppear finishes, self.userInfo will have the profile of
 //the user. How can I get here each textField  of the tableView so I can
   //populate each one of them with data from  self.userInfo?



         if !self.userInfo.isEmpty{

switch indexPath.row{
    case 0:
         cell.textField.text = self.userInfo[0].FirstName + " " + self.userInfo[indexPath.row].LastName
    case 1:
        cell.textField.text = self.userInfo[0].PhoneNumber

    case 2: cell.textField.text = self.userInfo[0].EmailAddress

    case 3: cell.textField.text = self.userInfo[0].FlatNumber

    case 4: cell.textField.text = self.userInfo[0].StreetAddress

    case 5: cell.textField.text = self.userInfo[0].PostCode

    default:
        break
     }
 }


    cell.textChangedCallBack = {(cell, text) in

        //get the cell's current index path 
        if let path = tableView.indexPath(for: cell) {

            //get the item at that row
            var item = self.placeHolderItems[path.row]

            //update the item with the new name  
        }  
    }

    return cell
  }
 }//end of EditProfileclass





extension EditProfile {


  //get user's profile in order to populate it in tableView
   func startObservingDB(callback:@escaping ((_ snapShot: [FireBaseData]) -> Void)) {

    //check if user is singed in
    guard let uid = FIRAuth.auth()?.currentUser?.uid  else {
        return
    }  

    dbRef.child(uid).child("profile").observeSingleEvent(of: .value, with: { (snapshot: FIRDataSnapshot) in
        var profileData = [FireBaseData]()

        for keyVal in snapshot.children{

            let userData = FireBaseData(snapshot: keyVal as! FIRDataSnapshot)
            profileData.append(userData)
                       }
        callback(profileData)

    }, withCancel: { (Error:Any) in 
        print("error is \(Error as! String)")

    })
    dbRef.removeAllObservers()

}//end of startObserving

}//end of EditProfile Class

Answer 1

通常要解决的问题是：用户在表格视图单元格中编辑了一个文本字段，现在我们要相应地更新数据模型。但哪个单元格包含此文本字段？

“哪个”这个概念实际上意味着：包含单元格所代表的索引路径是什么？如果我们知道这一点，我们可以轻松更新模型，因为如果我们的表视图数据源设计正确，我们就已经知道如何通过索引路径访问模型。

所以我所做的只是将视图层次结构从文本字段向上移动到单元格，然后询问表格视图此单元格表示的索引路径。这是我的应用中常用的模式：

GatewayFilter

Answer 2

你可以试试这个。

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "TextInputCell") as! TextInputTableViewCell

    cell.textField.isEnabled = placeHolderItems[indexPath.row].editable
    cell.textField.placeholder = placeHolderItems[indexPath.row].name


    if !self.userInfo.isEmpty{

        switch indexPath.row {
        case 0:
            cell.textField.text = self.userInfo[0].FirstName + " " + self.userInfo[indexPath.row].LastName
        case 1:
            cell.textField.text = self.userInfo[0].PhoneNumber

        case 2: cell.textField.text = self.userInfo[0].EmailAddress

        case 3: cell.textField.text = self.userInfo[0].FlatNumber

        case 4: cell.textField.text = self.userInfo[0].StreetAddress

        case 5: cell.textField.text = self.userInfo[0].PostCode

        default:
            break
        }
    }

    // Add tag to cell textField as cell current index
    cell.textField.tag = indexPath.row
    //Observer changes as user edits
    cell.txtField.addTarget(self, action: #selector(textFieldDidChange), for: .editingChanged)

    return cell
}

//MARK: - TextField Delegate
func textFieldDidChange(textfield: UITextField) {
    print("TextField \(String(describing: textfield.text)) Tag : \(textfield.tag)")

    switch textfield.tag {
    case 0:
        let Name  = textfield.text // or store where ever you want in sepearte array or update in userInfo
    case 1:
        let PhoneNumber   = textfield.text

    case 2:
        let EmailAddress   = textfield.text

    case 3:
        let FlatNumber   = textfield.text

    case 4:
        let StreetAddress   = textfield.text

    case 5:
        let PostCode  = textfield.text
    default:
        break
    }

}

// Don't forget to add UITextFieldDelegate

如何使用动态单元格获取UITableView中多个textField的值？

2 个答案: