如何根据swift 3中的数组选择复选标记？ [英] how to make checkmark to be selected depending on the array in swift 3?

问题描述

我有一个数组，其中选定的名称将被存储并传递到视图控制器之前，当我需要转到前一个视图控制器时，需要选择之前选择的复选标记，但这里只启用最后选择的元素问题是，如果我选择三个，那么它不是选择三个是检查只标记最后一个元素，但我需要三个选择的任何人可以帮助我如何选中三个元素的复选标记？

I am having array in which selected name will be stored and passed to before view controller and when ever i need to go previous view controller then the previously selected check mark needs to be selected but here it is enabling the last selected element only the problem is if i select three then it is not selecting three it is check marking only the last element but i need the three selected can anyone help me how to make the check mark to be selected for three elements ?

protocol ArrayToPass: class {
    func selectedArrayToPass(selectedStrings: [String])
}
class FilterSelectionViewController: UIViewController,UITableViewDataSource,UITableViewDelegate {

    var productName = [String]()
    var productprice = [String]()
    var imageArray = [String]()
    var idArray = [Int]()
    let urlString = "http://www.json-generator.com/api/json/get/bOYOrkIOSq?indent=2"
    var values = [String]()
    var selected: Bool?
    var delegate: ArrayToPass?
    var nameSelection: Bool?
    var namesArray = [String]()

    override func viewDidLoad() {
        super.viewDidLoad()
        self.downloadJsonWithURL()
        tableDetails.separatorInset = UIEdgeInsets.zero
        activityIndicator.startAnimating()
        tableDetails.isHidden = true
        tableDetails.dataSource = self
        tableDetails.delegate = self
        let rightBarButton = UIBarButtonItem(title: "Apply", style: UIBarButtonItemStyle.plain, target: self, action: #selector(applyBarButtonActionTapped(_:)))
        self.navigationItem.rightBarButtonItem = rightBarButton
        tableDetails.estimatedRowHeight = UITableViewAutomaticDimension
        tableDetails.rowHeight = 60
        // Do any additional setup after loading the view.
    }
    func applyBarButtonActionTapped(_ sender:UIBarButtonItem!){
        self.delegate?.selectedArrayToPass(selectedStrings: values)
        navigationController?.popViewController(animated: true)
    }
    func downloadJsonWithURL() {
        let url = NSURL(string: urlString)
        URLSession.shared.dataTask(with: (url as URL?)!, completionHandler: {(data, response, error) -> Void in
            if let jsonObj = try? JSONSerialization.jsonObject(with: data!, options: .allowFragments) as? NSArray {
                for item in jsonObj! {
                    if let itemDict = item as? NSDictionary{
                        if let name = itemDict.value(forKey: "name") {
                            self.productName.append(name as! String)
                        }
                        if let price = itemDict.value(forKey: "value") {
                            self.productprice.append(price as! String)
                        }
                        if let image = itemDict.value(forKey: "img") {
                            self.imageArray.append(image as! String)
                        }
                        if let id = itemDict.value(forKey: "id") {
                            self.idArray.append(id as! Int)
                        }
                    }
                }
                OperationQueue.main.addOperation({
                    self.tableDetails.reloadData()
                })
            }
        }).resume()
    }
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return productName.count
    }
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "filterSelectionCell", for: indexPath) as! FilterSelectionCell
        activityIndicator.stopAnimating()
        activityIndicator.hidesWhenStopped = true
        tableDetails.isHidden = false
        cell.brandProductName.text = productName[indexPath.row]
        if nameSelection == true{
            if namesArray.count != 0 {
                print(namesArray)
                for name in namesArray{
                    if productName[indexPath.row].contains(name){
                        print(productName[indexPath.row])
                        cell.accessoryType = .checkmark
                    }
                    else {
                        cell.accessoryType = .none
                    }
                }
            }
        }
        return cell
    }
    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath){
        selected = false
        if let cell = tableView.cellForRow(at: indexPath as IndexPath) {
            if cell.accessoryType == .checkmark{
                cell.accessoryType = .none
                print("\(productName[indexPath.row])")
                values = values.filter{$0 != "\(productName[indexPath.row])"}
                selected = true
            }
            else{
                cell.accessoryType = .checkmark
            }
        }
        if selected == true{
            print(values)
        }
        else{
            getAllTextFromTableView()
        }
        print(values)
    }
    func getAllTextFromTableView() {
    guard let indexPaths = self.tableDetails.indexPathsForSelectedRows else { // if no selected cells just return
    return
    }

    for indexPath in indexPaths {
        values.append(productName[indexPath.row])
    }
    }

这里是此图片

推荐答案

基本上不要操纵视图（单元格）。使用数据模型。

Basically do not manipulate the view (the cell). Use a data model.

struct Product {
    let name : String
    let value : String
    let img : String
    let id : Int

    var selected = false

    init(dict : [String:Any]) {
        self.name = dict["name"] as? String ?? ""
        self.value = dict["value"] as? String ?? ""
        self.img = dict["img"] as? String ?? ""
        self.id = dict["id"] as? Int ?? 0
    }
}

并且从不使用多个数组作为数据来源。这是一个非常糟糕的习惯。

And never use multiple arrays as data source . That's a very bad habit.

将数据源数组声明为

var products = [Product]()

解析JSON数据并执行（更好）错误处理

Parse the JSON data and do a (better) error handling

func downloadJsonWithURL() {
    let url = URL(string: urlString)!
    let task = URLSession.shared.dataTask(with: url) { (data, response, error) in
        if error != nil { print(error!); return }
        do {
            if let jsonObj = try JSONSerialization.jsonObject(with: data!) as? [[String:Any]] {
                self.products = jsonObj.map{ Product(dict: $0) }                
                DispatchQueue.main.async {
                    self.tableDetails.reloadData()
                }
            }
        } catch {
            print(error)
        }
    }
    task.resume()
}

in cellForRow ... 为标签指定名称并根据选择设置复选标记

in cellForRow... assign the name to the label and set the checkmark depending on selected

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "filterSelectionCell", for: indexPath)

    let product = products[indexPath.row]
    cell.textLabel!.text = product.name
    cell.accessoryType = product.selected ? .checkmark : .none
    return cell
}

didSelect ... 切换选择并重新加载行

func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
    let selected = products[indexPath.row].selected
    products[indexPath.row].selected = !selected
    tableView.reloadRows(at: [indexPath], with: .none)
}

---

获取所有选定项目也非常简单。

---

To get all selected items is very easy, too.

let selectedItems = products.filter{ $0.selected }

或仅获取名称

let selectedNames = products.filter{ $0.selected }.map{ $0.name }

根本无需从视图获取任何信息。 控制器始终从模型获取信息，并使用tableview数据源和委托来更新视图。

There is no need at all to get any information from the view. The controller gets the information always from the model and uses tableview data source and delegate to update the view.

如果要将数据传递给另一个视图控制器，请传递产品实例。它们包含所有相关信息。

If you want to pass data to another view controller pass Product instances. They contain all relevant information.

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