问题
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])
}
}
here is the image for this
回答1:
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
}
}
And never use multiple arrays as data source . That's a very bad habit.
Declare the data source array as
var products = [Product]()
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... 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
}
In didSelect... toggle selected and reload the row
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let selected = products[indexPath.row].selected
products[indexPath.row].selected = !selected
tableView.reloadRows(at: [indexPath], with: .none)
}
To get all selected items is very easy, too.
let selectedItems = products.filter{ $0.selected }
or get only the names
let selectedNames = products.filter{ $0.selected }.map{ $0.name }
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.
If you want to pass data to another view controller pass Product instances. They contain all relevant information.
来源：https://stackoverflow.com/questions/46397812/how-to-make-checkmark-to-be-selected-depending-on-the-array-in-swift-3