这是为什么？按钮在自定义单元格上切换状态，其背景图像由其他单元格重用

Question

自定义单元格上的按钮切换背景图像状态，由其他单元格重用，应该是重用问题，但不知道如何解决？你能给我一些建议吗？

    @objc func LickCheck(_ sender:UIButton){
        //Toggle button background image
        if !sender.isSelected {
          //code
        }else{
         //code
        }
        sender.isSelected = !sender.isSelected

    }

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

        let cell : FoneCell  = tableView.dequeueReusableCell(withIdentifier: "Focid", for: indexPath) as! FoneCell;

        cell.xxBtn.tag = indexPath.row;

        cell.xxBtn.addTarget(self, action: #selector(LickCheck), for: UIControl.Event.touchUpInside);

        return cell;
        }

FoneCell.swift：

lazy var xxxBtn : UIButton = {
        let btn = UIButton();
        btn.setImage(UIImage.init(named: "love_18x18_"), for: UIControl.State.normal);
        btn.setImage(UIImage.init(named: "love_on_20x20_"), for: UIControl.State.selected)


        return btn;
    }();

Answer 1

在UITableViewCell的override方法中

override func prepareForReuse() {
          super.prepareForReuse()
      //set default state here 
     self.imageView.image = nil
     self.toggleButton.isOn = false 
//.....
    }

或者你可以在tableViewcellForRowAtIndexPath中做同样的事情

 let cell = tableView.dequeueReusableCell(withIdentifier: "CustomCell", for: indexPath) as! CustomCell

    //Set default behaviour here
    cell.imageView.image = nil 
    cell.toggleButton.isOn = false 
  ....
return cell 

P.S您可以在viewController中创建数组以保存所选按钮的状态。例如

let isSelectedArray = Array(repeating: false, count: 100)
@objc func LickCheck(_ sender:UIButton){
        //Toggle button background image
        let tag = sender.tag
        if !isSelectedArray[tag]{

          //code
        }else{
         //code
        }
        isSelectedArray[tag] = !isSelectedArray[tag]
        sender.isSelected = !sender.isSelected
  }

Answer 2

我已经解决了这个问题，首先，定义一个点击按钮的全局记录数组

    lazy var numbercells:[Int] = []

其次，在

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

        let cell : FoneCell  = tableView.dequeueReusableCell(withIdentifier: "Focid", for: indexPath) as! FoneCell;

        if self.numbercells.contains(indexPath.row){
            cell.loveBtn.isSelected = true;
        }else{
            cell.loveBtn.isSelected = false;

        }
        cell.loveBtn.addTarget(self, action: #selector(LickCheck), for: UIControl.Event.touchUpInside);
        cell.loveBtn.tag = indexPath.row;

        return cell;

    }

最后

    @objc func LickCheck(_ sender:UIButton){

        if !sender.isSelected {
            self.numbercells.append(sender.tag);
            addDate(sender.tag)
        }else{
            self.numbercells = self.numbercells.filter(){$0 != sender.tag}
            deleteDate(sender.tag)
        }
        let posinton = IndexPath(row: sender.tag, section: 0);
        self.tableView.reloadRows(at: [posinton], with: UITableView.RowAnimation.none)

    }

这解决了单元上的按钮选择状态重用问题

Answer 3

这应该是这样的，

FoneCell.swift：

protocol FoneCellDelegate: class {
   func didSelectButton(atIndex: Int)
}

@IBOutlet var loveBtn: UIButton!

public weak var delegate: FoneCellDelegate?

func awakeFromNib() {
   super.awakeFromNib()
   loveBtn.addTarget(self, action: #selector(LickCheck), for: UIControl.Event.touchUpInside);
}

 @objc func LickCheck(_ sender:UIButton){
        //Toggle button background image
        if !sender.isSelected {
            addDate(sender.tag)
        }else{
            deleteDate(sender.tag)
        }
        sender.isSelected = !sender.isSelected
        delegate?.didSelectButton(atIndex: sender.tag)
    }

ViewController.swift

var buttonStates =  Array(repeating: false, count: 10)//if you need 10 rows

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

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

    let cell : FoneCell  = tableView.dequeueReusableCell(withIdentifier: "Focid", for: indexPath) as! FoneCell;

    cell.loveBtn.tag = indexPath.row;
    cell.loveBtn.isSelected = buttonStates[indexPath.row]
    cell.delegate = self // Implement protocol on cell's class. And update the value in buttonStates when state toggled
    return cell
}

func didSelectButton(atIndex: Int) {
      buttonStates[atIndex] = !buttonStates[atIndex]
      tableView.reloadData()
}