How to pass data from one view controller to the other SWIFT

问题

I am making an app where a table view with a search bar and scope bar has to segue to a detail view controller and that detail view controller has to display data based on which cell is selected. I have an array with structs set up to sort and search for the items. I need to keep this feature, I have another swift class for my detail view controller that I will put if/else statements into that deal with displaying the data based on what cell I select. What I need to know how to do is attach a variable to the cells and pass that variable to the detail view controller to use in my if/else statements so that I can display the data. If this is not the correct way to do this, please let me know.

Struct code

struct Booth {
    let category : String
    let name : String
}

Table view controller code

import UIKit

class BoothsTableViewController: UITableViewController {    

var booths = [Booth]()
var filteredBooths = [Booth]()

override func viewDidLoad() {
    super.viewDidLoad()

    //fill array with data
    self.booths = [Booth(category: "Tech", name: "Conference App"),
        Booth(category: "Tech", name: "Space Shooter"),
        Booth(category: "Tech", name: "RollABall"),
        Booth(category: "Animation", name: "Sugar Hill City Model"),
        Booth(category: "Animation", name: "3D Sculpting 101"),
        Booth(category: "Animation", name: "HowTo - Texture"),
        Booth(category: "Science", name: "AP Biology for Dummies"),
        Booth(category: "Science", name: "Cells"),
        Booth(category: "Science", name: "Space")]

    //reload the table
    self.tableView.reloadData()
}

override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    if tableView == self.searchDisplayController!.searchResultsTableView {
        return self.filteredBooths.count
    } else {
        return self.booths.count
    }
}

override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    //ask for a reusable cell from the tableview, the tableview will create a new one if it doesn't have any
    let cell = self.tableView.dequeueReusableCellWithIdentifier("Cell") as UITableViewCell

    var boothsCheck : Booth
    // Check to see whether the normal table or search results table is being displayed and set the Booth object from the appropriate array
    if tableView == self.searchDisplayController!.searchResultsTableView {
        boothsCheck = filteredBooths[indexPath.row]
    } else {
        boothsCheck = booths[indexPath.row]
    }

    // Configure the cell
    cell.textLabel.text = boothsCheck.name
    cell.accessoryType = UITableViewCellAccessoryType.DisclosureIndicator

    return cell
}

func filterContentForSearchText(searchText: String, scope: String = "All") {
    self.filteredBooths = self.booths.filter({( Booth : Booth) -> Bool in
        var categoryMatch = (scope == "All") || (Booth.category == scope)
        var stringMatch = Booth.name.rangeOfString(searchText)
        return categoryMatch && (stringMatch != nil)
    })
}

func searchDisplayController(controller: UISearchDisplayController!, shouldReloadTableForSearchString searchString: String!) -> Bool {
    let scopes = self.searchDisplayController!.searchBar.scopeButtonTitles as [String]
    let selectedScope = scopes[self.searchDisplayController!.searchBar.selectedScopeButtonIndex] as String
    self.filterContentForSearchText(searchString, scope: selectedScope)
    return true
}

func searchDisplayController(controller: UISearchDisplayController!,
    shouldReloadTableForSearchScope searchOption: Int) -> Bool {
        let scope = self.searchDisplayController!.searchBar.scopeButtonTitles as [String]
        self.filterContentForSearchText(self.searchDisplayController!.searchBar.text, scope: scope[searchOption])
        return true
}

override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
    self.performSegueWithIdentifier("BoothDetail", sender: tableView)
}

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {

    if segue.identifier == "BoothDetail" {

        let BoothDetailViewController = segue.destinationViewController as UIViewController


        if sender as UITableView == self.searchDisplayController!.searchResultsTableView {
            let indexPath = self.searchDisplayController!.searchResultsTableView.indexPathForSelectedRow()!
            let destinationTitle = self.filteredBooths[indexPath.row].name
            BoothDetailViewController.title = destinationTitle


    } else {

            let indexPath = self.tableView.indexPathForSelectedRow()!
            let destinationTitle = self.booths[indexPath.row].name
            BoothDetailViewController.title = destinationTitle
            }
        }
    }
}

Segue code

    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {

    if segue.identifier == "BoothDetail" {

        let BoothDetailViewController = segue.destinationViewController as UIViewController


        if sender as UITableView == self.searchDisplayController!.searchResultsTableView {
                let indexPath = self.searchDisplayController!.searchResultsTableView.indexPathForSelectedRow()!
                let destinationTitle = self.filteredBooths[indexPath.row].name
                BoothDetailViewController.title = destinationTitle        
        } else {            
                let indexPath = self.tableView.indexPathForSelectedRow()!
                let destinationTitle = self.booths[indexPath.row].name
                BoothDetailViewController.title = destinationTitle
            }
        }
    }
}

回答1:

For instance, in your BoothsTableViewController create variable holding the currently selected Booth, which you assign in didSelectRowAtIndexPath. You can then pass this variable to the detail view controller in your prepareForSegue method.

回答2:

Create a member variable/object in detailViewController. Set this object in prepareforSegue in your current TableViewController. This way the detailViewController will have the cell object the user clicked.

来源：https://stackoverflow.com/questions/26662256/how-to-pass-data-from-one-view-controller-to-the-other-swift