出乎意料地在prepareForSegue中找到了nil IBOutlet [英] Unexpectedly found nil IBOutlet in prepareForSegue

问题描述

我有一个详细视图控制器，我想使用indexPath行将标签文本设置为从数组中获取的值。

I have a detail view controller, and I would like to set the label text to a value taken from an array using an indexPath row.

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    if(segue.identifier == "showView"){
        let detailVC: DetailViewController = segue.destinationViewController as! DetailViewController
        let indexPath = self.MainTableView.indexPathForSelectedRow!
        detailVC.label.text = "Test"
        self.MainTableView.deselectRowAtIndexPath(indexPath, animated: true)
        }
}

我不断收到致命错误：在展开可选值时意外发现nil。我已经尝试将 detailVC.label.text =Test切换为 detailVC.label.text = names [indexPath.row] 但我每次都会遇到同样的错误。

I keep getting a fatal error: unexpectedly found nil while unwrapping an optional value. I have tried switching detailVC.label.text = "Test" to detailVC.label.text = names[indexPath.row] but I keep getting the same error every time.

我使用相同的代码行来更改单元格的标签文本，没有错误，但是对于这个标签在空白视图的中心我似乎无法得到它对？有什么需要改变的想法？

I used the same lines of code for changing the cell's label text, with no errors, but for this label in the center of a blank view I cannot seem to get it right? Any thoughts on what needs to be changed?

顺便说一下，详细视图控制器中的标签是 @IBOutlet weak var label：UILabel！

By the way, the label in the detail view controller is @IBOutlet weak var label: UILabel!

推荐答案

您无法访问 IBOutlet 的 DetailViewController in prepareForSegue 因为它们尚未连接。

You cannot access IBOutlets of DetailViewController in prepareForSegue because they are not connected yet.

如评论中所述，创建一个 String DetailViewController 中的属性，在 prepareForSegue 中设置并设置 viewDidLoad 或 viewWillAppear 中标签的 text 属性 DetailViewController 。

As mentioned in the comments create a String property in DetailViewController, set it in prepareForSegue and set the text property of the label in viewDidLoad or viewWillAppear of DetailViewController.

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