使用委托将照片导入特定的 tableview 单元格

Question

我希望我的 swift 代码使用委托将照片从照片库导入特定的表格视图单元格。现在发生的事情是将照片导入到始终进入第一个单元格。因此，如果用户单击第二个单元格中的导入按钮，照片应该转到第二个单元格。标签不工作。如果可能，我想使用委托。

import UIKit

class ViewController: UIViewController,UITableViewDelegate,UITableViewDataSource,CustomTvCellDelegateadd, UIImagePickerControllerDelegate & UINavigationControllerDelegate {
    @objc func addCeller(_ customTV: CustomTv, location: CGPoint) {
        selectedIndexPath = IndexPath(row: 0, section: 0)
        let imagePicker = UIImagePickerController()
        imagePicker.delegate = self
        imagePicker.sourceType = .photoLibrary
        present(imagePicker, animated: true, completion: nil)
        
      
    }
    
   
    var cellCount = 5
    var tableview = UITableView()
    var selectedIndexPath = IndexPath(row: 0, section: 0)


    
    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
        guard let selectedImage = info[.originalImage] as? UIImage else {
            fatalError("Expected a dictionary containing an image, but was provided the following: \(info)")
        }
        guard let cell = tableview.cellForRow(at: selectedIndexPath) as? CustomTv else { return }
        cell.pic.image = selectedImage
        tableview.reloadData()
        
        dismiss(animated: true, completion: nil)
    }
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return cellCount // use a variable here so you can change it as you delete cells, else it will crash
    }
    func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
        return 118
    }
   
    
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! CustomTv
        cell.addd.tag = indexPath.row
        cell.delegatef = self
     
    
      cell.addd.addTarget(self, action: #selector(addCeller), for: .touchDown)
        return cell
    }
    

 
    
    override func viewDidLoad() {
        super.viewDidLoad()

        tableview.frame = CGRect(x: 0, y: 0, width: view.frame.width, height: view.frame.height * 0.8)
        
        
        view.addSubview(tableview)

 
        tableview.register(CustomTv.self, forCellReuseIdentifier: "cell")
        tableview.delegate = self
        tableview.dataSource = self
      
    }
    
}

// you need to declare a cell delegate that will let your tableview know when the button was tapped on the cell


protocol CustomTvCellDelegateadd: AnyObject {
    func addCeller(_ customTV: CustomTv, location: CGPoint)
}
class CustomTv: UITableViewCell { // it's good form to Pascal case your class name ;)
    
    
    weak var delegatef: CustomTvCellDelegateadd?
    lazy var backView : UIView = {
        let view = UIView(frame: CGRect(x: 10, y: 6, width: self.frame.width  , height: 110))
        view.backgroundColor = .green
        
        return view
    }()


    
    lazy var addd : UIButton = {
        let btn = UIButton(frame: CGRect(x: 250-25, y: 0, width: 100 , height: 55))
        btn.backgroundColor = .brown
        btn.setTitle("Add", for: .normal)
        btn.titleLabel?.textAlignment = .center
        return btn
        
    }()


        lazy var pic : UIImageView = {
            let btn = UIImageView(frame: CGRect(x: 50-25, y: 6, width: 100 , height: 110))
            btn.backgroundColor = .systemPink
    
            return btn
    
        }()
 
   
    override func layoutSubviews() {
        backView.clipsToBounds = true
        backView.frame =  CGRect(x: 0, y: 6, width: bounds.maxX  , height: 110)
        
        // moved these calls here instead of on setSelected(_selected:animated:)
        addSubview(backView)

        backView.addSubview(addd)
   
        backView.addSubview(pic)
        
        

        
 
      
    }
    

}

Answer 1

问题：

selectedIndexPath = IndexPath(row: 0, section: 0)

addCeller 方法中的硬编码 indexPath 值

解决方案：

您需要对代码进行一些重组。

1. 捕获单元格本身中的按钮选择器，因此您可以将 self 作为参数返回/传递给协议方法。这不是一个非常理想的解决方案（因为您只对索引路径而不是单元格本身感兴趣，但我不太清楚您在返回 CustomTv 作为协议方法中的争论背后的想法，所以我只是保持更改与那个决定）

class CustomTv: UITableViewCell { // it's good form to Pascal case your class name ;)
    weak var delegatef: CustomTvCellDelegateadd?
    lazy var backView : UIView = {
        let view = UIView(frame: CGRect(x: 10, y: 6, width: self.frame.width  , height: 110))
        view.backgroundColor = .green

        return view
    }()



    lazy var addd : UIButton = {
        let btn = UIButton(frame: CGRect(x: 250-25, y: 0, width: 100 , height: 55))
        btn.backgroundColor = .brown
        btn.setTitle("Add", for: .normal)
        btn.titleLabel?.textAlignment = .center
        btn.addTarget(self, action: #selector(addButtonTapped), for: .touchUpInside)
        return btn
    }()


    lazy var pic : UIImageView = {
        let btn = UIImageView(frame: CGRect(x: 50-25, y: 6, width: 100 , height: 110))
        btn.backgroundColor = .systemPink

        return btn

    }()


    override func layoutSubviews() {
        backView.clipsToBounds = true
        backView.frame =  CGRect(x: 0, y: 6, width: bounds.maxX  , height: 110)

        // moved these calls here instead of on setSelected(_selected:animated:)
        addSubview(backView)

        backView.addSubview(addd)

        backView.addSubview(pic)
    }

    @objc func addButtonTapped() {
        self.delegatef?.addCeller(self)
    }
}

2. 现在您已将CustomTv 实例作为方法调用的一部分，通过询问tableView 直接获取索引路径

func addCeller(_ customTV: CustomTv) {
        if let indexPath = self.tableview.indexPath(for: customTV) {
            selectedIndexPath = indexPath
        }
        let imagePicker = UIImagePickerController()
        imagePicker.delegate = self
        imagePicker.sourceType = .photoLibrary
        present(imagePicker, animated: true, completion: nil)
}

3. 现在您已经设置了按钮目标，从cellForRowAtIndexPath中删除语句

cell.addd.addTarget(self, action: #selector(addCeller), for: .touchDown)

编辑 1：

正如下面 cmets 中提到的 OP，这些修改导致编译错误，因为我修改了协议方法声明并且没有在答案中更新它，因此编辑以反映相同。

protocol CustomTvCellDelegateadd: AnyObject {
    func addCeller(_ customTV: CustomTv)
}

正如我在下面的 cmets 中已经解释的那样，我不确定方法中 location 参数的目的（如果它只是为了传达此解决方案不再需要的所选单元格的索引），因此我省略了声明中导致编译错误的参数:)