Add/Remove Multiple Checkmarks on Selected Rows in Swift 4 UITableView [duplicate]

问题

Asking because all solutions available are for Swift 3. Also, I am dealing with a problem that when I scroll up and down after highlighting + selecting a row, new rows that appear with the same indexPath (after scrolling) will also be checked (but not highlighted).

func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {    
    if let cell = tableView.cellForRow(at: indexPath) {
        cell.accessoryType = .checkmark
    }
}
func tableView(_ tableView: UITableView, didDeselectRowAt indexPath: IndexPath) {
    if let cell = tableView.cellForRow(at: indexPath) {
        cell.accessoryType = .none
    }
}

回答1:

Instead of change accessoryType on didSelectRowAt and didDeselectRowAt methods, you should override and do it on setSelected(_:animated:) from your cell class.

class YourCellClass: UITableViewCell {

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

    if selected {
      accessoryType = .checkmark
    } else {
      accessoryType = .none
    }
  }

}

回答2:

You can possibly Use my Way:

Take a button inside a cell and use it like this:

var arrSelectedRows:[Int] = []

//MARK:- UITableView Delegate Methods
func numberOfSections(in tableView: UITableView) -> Int {
    return 1;
}

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


func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

    let cellIdentifier : String = "MenuPopupTBCell";

    var cell : MenuPopupTBCell! = tblMenuListing.dequeueReusableCell(withIdentifier: cellIdentifier) as! MenuPopupTBCell;
    if (cell == nil) {
        cell = MenuPopupTBCell.init(style: UITableViewCellStyle.default, reuseIdentifier: cellIdentifier);
    }

    cell.btnCategoryTitle.imageView?.contentMode = .scaleAspectFit
    let data = arrCategoryData[indexPath.row] as! [String:Any]
    cell.btnCategoryTitle.setTitle(data["title"] as? String, for: .normal)
    let id = data["id"] as! Int

    if arrSelectedRows.contains(id){
        cell.btnCategoryTitle.setImage(UIImage(named:"checkBoxChecked"), for: .normal)
    }else{
        cell.btnCategoryTitle.setImage(UIImage(named:"checkBocUnchecked"), for: .normal)
    }
    cell.btnCategoryTitle.tag = id
    cell.btnCategoryTitle.addTarget(self, action: #selector(checkBoxSelection(_:)), for: .touchUpInside)

    return cell;
}

@objc func checkBoxSelection(_ sender:UIButton)
{

    if self.arrSelectedRows.contains(sender.tag){
        self.arrSelectedRows.remove(at: self.arrSelectedRows.index(of: sender.tag)!)
    }else{
        self.arrSelectedRows.append(sender.tag)
    }
    self.tblMenuListing.reloadData()
}

This way you get all the selected id in the arrSelectedRows so you can use it as required

Output:-

回答3:

you can use a collection to determine if an item is checked or not. and add the following:

var items: [(text: String, checked: Bool)] = [] //example, can be what ever you want

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = UITableViewCell() //you can reuse cell for performance
    let item = items[indexPath.row] 
    cell.textLabel?.text = item.text //set text
    cell.accessoryType = item.checked ? .checkmark : .none //mark cell base on array
    return cell
}

and in the other methods (didSelect & didDeselect) update the data in the array

func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {    
    if let cell = tableView.cellForRow(at: indexPath) {
        cell.accessoryType = .checkmark
        items[indexPath.row].checked = true //add this
    }
}
func tableView(_ tableView: UITableView, didDeselectRowAt indexPath: IndexPath) {
    if let cell = tableView.cellForRow(at: indexPath) {
        cell.accessoryType = .none
        items[indexPath.row].checked = false //add this
    }
}

after this modifications - your table view won't mark wrong cell again

来源：https://stackoverflow.com/questions/50112804/add-remove-multiple-checkmarks-on-selected-rows-in-swift-4-uitableview

标签

ios

swift

uitableview

cells

checkmark