如何维护TableView滚动以停止重复使用单元格

Question

I have multiple sections in tableview. I have multiple questions and multiple answers of each question. In multiple answers, I have one option and that is other (option). when I select the button of other, then it shows the text field for advice. Now i need to maintain the data of text field and that selected option's (Other) text when scrolling in tableview.I am using below code for all answer.

if (indexPath.section == 2)
       {
           let cellidentifier="cell3"
           let cell=tableView.dequeueReusableCell(withIdentifier: cellidentifier,for:indexPath as IndexPath)  as! TextfieldTableViewCell

           let object_3:AnswerBaseClass = arrobject_answer[0][indexPath.row]
           //print("arrobject is\(arrobject_answer[0][indexPath.row])")

           if object_3.answer == "O"
           {
                  // cell.lbl_answer.isHidden = true
                   cell.btn_selected.isHidden=true
                   //cell.lbl_answer_height.constant = 0
                   cell.Other_textfield.tag = 101
                   cell.Other_textfield.borderStyle = .line
                   cell.Other_textfield_top.constant = -30
                   cell.Height_2.constant = 30
           }
           else
           {
               cell.lbl_answer?.text = object_3.answer!
               cell.Other_textfield_top.constant = 12
               cell.Height_2.constant = 0
               cell.lbl_answer.isHidden = false
               cell.btn_selected.isHidden=false
               if answer_main_data[0][indexPath.row] == true
               {
                   cell.lbl_answer.tag = indexPath.row
                   cell.btn_selected.isSelected=true
                   if cell.lbl_answer.text == "Other"
                   {
                       for subview in cell.contentView.subviews
                       {
                           subview.removeFromSuperview()
                       }
                       if arrOtherTextfield_2.indices.contains(indexPath.row)
                       {
                           cell.addSubview(arrOtherTextfield_2[indexPath.row])
                       }
                       else
                       {
                           cell.Other_textfield.tag = 1100
                           cell.Other_textfield.borderStyle = .line
                           cell.Height_2.constant = 30
                           arrOtherTextfield_2.append(cell.Other_textfield)
                       }
                   }
                   else
                   {
                       cell.Height_2.constant = 0
                   }
               }
               else
               {
                   cell.Other_textfield_top.constant = 12
                   cell.btn_selected.isSelected=false
                   cell.Height_2.constant = 0
               }
           }
           cell.Other_textfield.borderStyle = .line
           return cell
       }

Answer 1

You will have to retain (store in some dictionary) the data entered in textfield, otherwise it will be lost when you scroll table and cell is reloaded. If you don't want to retain then you should use scroll view instead of table view. In scrollview it will not redraw UI even if you scroll up and down.

Answer 2

You need to separate UI and data. You embed data into your cell and when cells are reused, you lost data.

You can do 2 things:

1. Create a ViewModel class which contains data of cell: text, color, etc. Of course you need to update your ViewModel as you receive input You can google "MVVM pattern" for more information. Even if your cell is reused, your data is safe in ViewModel object.
2. You can keep your cells in an Array so that they won't be reused.