Question

我已经看过几个帖子，但无法弄清楚问题

我想将数据从UICollectionView Controller传递到我的UIViewController，以下是详细信息

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()

}

}

但是当我运行这个时，我无法传递值并收到以下错误：

致命错误：在解包可选值时意外发现nil

请建议如何纠正此问题，谢谢

Answer 1

我会建议你采用以下方法。在didSelectItemAt方法中写下面的代码。

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分配给laber，如下所示。

self.Label.text = itemName

Answer 2

不使用UIlabel label1，而是声明字符串变量eg。标题。并在代码中更改以下行。

类SelctionViewController：UIViewController {

var title = ""

@IBOutlet weak var Label: UILabel!

override func viewDidLoad() {
    super.viewDidLoad()

   Label.text = title
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()

}

prepareForSegue方法：而不是detailVC.label1.text，请使用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

    }
}
}

Answer 3

@lazyCoder，谢谢你帮助我

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)

}

此代码现在工作得很好..查看

从UicollectionView控制器传递数据时出现问题

3 个答案: