从UICollectionView Controller传递数据中的问题

Question

我看过几个帖子，但无法弄清楚这个问题

我想将数据从UicollectionView Controller传递给我的UiviewController，这是详细信息

func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    if segue.identifier == "Selection2" {
        if let indexPath = self.collectionView?.indexPath(for: sender as! UICollectionViewCell) {
            let detailVC = segue.destination as! SelectionViewController
            //
            let item = items1[indexPath.row]
            //passing the item name which is selected 
            detailVC.label1.text = item.name1

        }
    }
}

这是SelectionViewController代码：

import UIKit
class SelctionViewController: UIViewController {
var label1 : UILabel!

@IBOutlet weak var Label: UILabel!
override func viewDidLoad() {
    super.viewDidLoad()

  Label.text = self.label1.text

    // Do any additional setup after loading the view.
}
override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
}
}

但是当我运行时，我无法传递值并获得以下错误：

致命错误：未包装可选值

时出乎意料地发现了无效

请建议如何纠正，谢谢

Answer 1

我会建议您采用以下方法。在didSelectItemat方法中写下以下代码。

let detailVC  = self.storyboard?.instantiateViewController(withIdentifier: "Selection2") as! SelectionViewController
let item = items1[indexPath.row]
//Create string property itemName and pass the value
detailVC.itemName = item.name1
self.navigationController?.pushViewController(detailVC, animated: true)

在selectionViewController中，将itemname cass itemname如下所示。

self.label.text = itemName

Answer 2

@lazycoder，感谢您帮助我

override func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
    let detailVC  = self.storyboard?.instantiateViewController(withIdentifier: "Selection2") as! SelctionViewController
    detailVC.itemName = self.items1[indexPath.row].name1

self.navigationController?.pushViewController(detailVC, animated: true)
}

现在，此代码工作正常。Cheers

Answer 3

而不是使用uilabel label1，而是声明字符串变量。标题。并更改代码中的以下行。

class selctionViewController：uiviewController {

var title = ""
@IBOutlet weak var Label: UILabel!
override func viewDidLoad() {
    super.viewDidLoad()
   Label.text = title
}
override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
}

Preparforsegue方法：而不是详细信息vc.label1.text，使用detailvc.title

func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "Selection2" {
    if let indexPath = self.collectionView?.indexPath(for: sender as! UICollectionViewCell) {
        let detailVC = segue.destination as! SelectionViewController
        let item = items1[indexPath.row]
        detailVC.title = item.name1 // instead of detailVC.label1.text, use detailVC.title
    }
}
}