我收到錯誤消息: let indexPath = self.menuTable.indexPathForSelectedRow()!
。 似乎我沒有從indexPathForSelectedRow
獲得價值。我從CSV
文件解析到Core Data
。不知道它是否重要。我是編碼新手,所以不確定我是否缺少明顯的東西。致命錯誤:在解包可選值時意外發現零:Swift,核心數據
import UIKit
import CoreData
class MenuTableViewController: UITableViewController {
@IBOutlet var menuTable: UITableView!
private var menuItems:[MenuItem] = []
var fetchResultController:NSFetchedResultsController!
override func viewDidLoad() {
super.viewDidLoad()
// Load menu items from database
if let managedObjectContext = (UIApplication.sharedApplication().delegate as! AppDelegate).managedObjectContext {
let fetchRequest = NSFetchRequest(entityName: "MenuItem")
var e: NSError?
menuItems = managedObjectContext.executeFetchRequest(fetchRequest, error: &e) as! [MenuItem]
if e != nil {
println("Failed to retrieve record: \(e!.localizedDescription)")
}
}
// Make the cell self size
self.tableView.estimatedRowHeight = 66.0
self.tableView.rowHeight = UITableViewAutomaticDimension
self.tableView.layoutIfNeeded()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// MARK: - Table view data source
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
// Return the number of sections.
return 1
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// Return the number of rows in the section.
return menuItems.count
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = menuTable.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as! MenuTableViewCell
// Configure the cell...
cell.nameLabel.text = menuItems[indexPath.row].name
cell.detailLabel.text = menuItems[indexPath.row].detail
// cell.priceLabel.text = "$\(menuItems[indexPath.row].price as! Double)"
return cell
}
override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath)
{
self.performSegueWithIdentifier("showFront", sender: self)
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?)
{
if (segue.identifier == "showFront")
{
var upcoming: CardFrontViewController = segue.destinationViewController as! CardFrontViewController
let indexPath = self.menuTable.indexPathForSelectedRow()!
let titleString = menuItems[indexPath.row].name
upcoming.titleStringViaSegue = titleString
self.menuTable.deselectRowAtIndexPath(indexPath, animated: true)
}
}
}
你的故事板中的單元格是否與segue相連? –
是的,我將單元連接到故事板segue,「顯示(例如Push)」,標識符爲「showFront」。 – Sara