swift - 通过 Swift segue 传递数据每隔一段时间就有效

Question

我有一个 tableview，它读取和 RSS feed 的情景广播节目。我希望所选节目的播放列表传递给第二个 Controller ，以便在选择单元格时在 TextView 中查看。我正在使用 segue，当我两次(每隔一次)选择同一个单元格时它会起作用。我到处搜索都没有成功，这让我发疯了!请帮忙。这是我的代码

     // Only grab the data at the selected cell
        //
    override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {

        // Load the variable to hold whats in the row
        currentList = feeds.objectAtIndex(indexPath.row).objectForKey("itunes:summary") as NSString

        // Load the row number
        myRow = (indexPath.row)

    }

    // Pass the data thru the segue
    override func prepareForSegue(segue: (UIStoryboardSegue!), sender: AnyObject!) {
        if (segue.identifier == "mySegue") {

//            var vc = segue.destinationViewController as secondViewController
//            vc.toPass = currentList
//            println(vc.toPass)



            let vc = segue.destinationViewController as secondViewController
            let indexPath = self.tableView.indexPathForSelectedRow
            vc.toPass = currentList
        }
    }
}

这是我的第二个 View Controller 的代码

 import UIKit

class secondViewController: UIViewController {

    // Create a property to accept the data

    @IBOutlet weak var textPlayList: UITextView!



    // Create a variable to store the data

    var toPass:String!

    override func viewDidLoad() {
        super.viewDidLoad()



        textPlayList.text = toPass
        textPlayList.textColor = UIColor .whiteColor()
        textPlayList.font = UIFont .boldSystemFontOfSize(10)

    }


}

Answer 1

问题是 prepareForSegue 发生在 didSelectRowAtIndexPath 之前，因此您的 currentList 变量设置得太晚，无法在 prepareForSegue< 中使用.

要解决此问题，请移动此代码:

    // Load the variable to hold whats in the row
    currentList = feeds.objectAtIndex(indexPath.row).objectForKey("itunes:summary") as NSString

到prepareForSegue:

    override func prepareForSegue(segue: (UIStoryboardSegue!), sender: AnyObject!) {
        if (segue.identifier == "mySegue") {
            let vc = segue.destinationViewController as secondViewController
            if let indexPath = self.tableView.indexPathForSelectedRow() {
                let currentList = feeds.objectAtIndex(indexPath.row).objectForKey("itunes:summary") as NSString
                vc.toPass = currentList
            }
        }
    }

一般来说，如果您正在使用 segue，则不需要 didSelectRowAtIndexPath，因为 prepareForSegue 是您设置过渡的地方。