Tableview单元格多个复选标记选择以将单元格数据添加到单个数组中Swift 4.2？

Question

My scenario, I have loaded my JSON data into tableView with help of codable . Here, I have added my tableView cell multiple check mark select and deselect . Now, If I am selecting tableView cell I can able to get cell data but I want to add within one array , same if I am unselecting cell It should remove from the array. Selected cell data I am moving to another ViewController . I would like to know how to do that.

My Code

// method to run when table view cell is tapped
    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        print("You tapped cell number \(indexPath.row).")

        if let cell = tableView.cellForRow(at: indexPath as IndexPath) {
            if cell.accessoryType == .checkmark {
                cell.accessoryType = .none
            } else {
                cell.accessoryType = .checkmark
                let item = users[indexPath.row]
                print(item) // here printing cell selection data 
            }
        }
    }

My Cell Selection current output

You tapped cell number 1.
User(userId: "121”, active: 1, name: example_table.Name(firstname: "jack", lastname: "m"))
You tapped cell number 2.
User(userId: "122”, active: 1, name: example_table.Name(firstname: “rose”, lastname: “h”))
You tapped cell number 3.
User(userId: "123”, active: 1, name: example_table.Name(firstname: “makj”, lastname: “i”))

Answer 1

You can try

var selectedArr = [Item]()
var users = [Item]()

func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
    print("You tapped cell number \(indexPath.row).")
    let item = users[indexPath.row]
    if let cell = tableView.cellForRow(at: indexPath) { // you can also omit the if let and force-unwrap as in this case cell will never be nil 
        if cell.accessoryType == .checkmark {
            cell.accessoryType =  .none
            selectedArr.remove(where:{ $0 == item })
        } else {
            cell.accessoryType = .checkmark
            selectedArr.append(item)
        }
    }
}

Then inside cellForRowAt

let cell = ////
let item = users[indexPath.row]
cell.accessoryType = selectedArr.contains(item) ? .checkmark : .none

Also make sure model named Item conforms to Equatable

---

given

  for (index, element) in item.enumerated() { 
     print("Item \(index): \(element)")
  }

that gives

Item 0: 121, Item 1: 122, Item 2: 123

Then it's an array of Ints , so do

 let res = item.map{ "\($0)" }.joined(separator: ",")

Answer 2

So it sounds like you want to be able to have an array that contains all of the selected Users. Then what you would do is have an array like this instantiated in the class declaration:

var users:[Users] = []

Now what you should be doing is leveraging swift's protocols in order to handle the heavy lifting for you; meaning, when removing a previously selected user from the Users array, you shouldn't need a for loop, but something more familiar: contains.

extension User: Equatable {
    static func == (lhs: User, rhs: User) -> Bool {
        return lhs.userId == rhs.userId
    }
}

So now you can call this when removing or adding, for example:

var thisUser = User(userId: "123”, active: 1, name: example_table.Name(firstname: “makj”, lastname: “i”))

if users.contains(thisUser) {
    users.removeAtIndex(users.indexOf(thisUser))
} else {
    //Add the user to the array here for example
    users.append(thisUser)
}

Answer 3

Don't use an extra array, add the selected information to your model.

struct User : Codable {

    var isSelected = false
    // ... other members

}

Assuming the data source array is declared as users , set the checkmark depending on the isSelected value in cellForRowAt

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath)
    let user = users[indexPath.row]
    cell.accessoryType = user.isSelected ? .checkmark : .none

    ... 
}

In didSelectRowAt just toggle isSelected and reload the row

override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
    users[indexPath.row].isSelected.toggle()
    tableView.reloadRows(at: [indexPath], with: .none)
}

To get all selected users just filter the array

let selectedUsers = users.filter{ $0.isSelected }