风投之间的快速传递数据

Question

我是Swift的新手，我想知道为什么我从Obj编译的这段代码在这里不起作用。

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
        if segue.identifier == "scoreDetail" {
            let indexPath = self.tableView.indexPathForSelectedRow()
            let object = self.fetchedResultsController.objectAtIndexPath(indexPath) as NSManagedObject

            let itemVC: ScoreVC = segue.destinationViewController as ScoreVC
            itemVC.detailItem = object
        }
    }

这是故事板。我有一个从单元格到UINavigatorController的UINavigatorController

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只要单击UITableViewCell，我就会得到这个错误

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Answer 1

这个问题与斯威夫特无关。destinationViewController是导航控制器，而不是ScoreVC，所以您翻译的代码也不应该工作(如果它有相同的设置)。应该是这样的，

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
        if segue.identifier == "scoreDetail" {
            let indexPath = self.tableView.indexPathForSelectedRow()
            let object = self.fetchedResultsController.objectAtIndexPath(indexPath) as NSManagedObject

            let nav : UINavigationController = segue.destinationViewController
            let itemVC: ScoreVC =  nav.topViewController as ScoreVC
            itemVC.detailItem = object
        }
    }