Ios 在collectionviewcontroller中单击图像时在detailviewcontroller中获取图像详细信息

My CollectionViewController包含一个图像。当我在CollectionViewController中单击图像时，它会将我带到detailviewcontroller，在那里我要编辑图像的详细信息。当我输入URL等详细信息，然后单击“上一步”按钮时，它应该从URL获取图像并替换我的CollectionViewController中的图像

我有两个问题：

当我在CollectionViewController中单击图像时，它会打开detailviewcontroller，但不会显示我单击的图像的url。 单击“上一步”按钮时，它不会将我带回CollectionViewController。 详细视图控制器

import UIKit

class ViewController: UIViewController, UITextFieldDelegate {

  var photo: Photo!

  @IBOutlet weak var textURL: UITextField!

  @IBOutlet weak var textTitle: UITextField!
  @IBOutlet weak var textTags: UITextField!
  @IBOutlet weak var imageView: UIImageView!

  override func viewDidLoad() {
    super.viewDidLoad()

    // Do any additional setup after loading the view, typically from a nib.
  }

  override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
  }

  func textFieldShouldReturn(textField: UITextField) -> Bool {
    let urlString = textField.text
    photo.url = urlString
    let DatatoImage: (NSData?) -> Void = {
      if let d = $0 {
        let image = UIImage(data: d)
        self.imageView.image = image
      } else {
        self.imageView.image = nil
      }
      //textField.resignFirstResponder()
    }
    if let d = photo.data {
      DatatoImage(d)
      textField.resignFirstResponder()
      let image = UIImage(data: d)
      self.imageView.image = image
    } else {
      photo.loadImage(DatatoImage)
    }
    return true
  }
}

我的masterViewController

import UIKit

let reuseIdentifier = "Cell"

class PhotosCollectionViewController: UICollectionViewController {

  var photos = Array<Photo>()

  override func viewDidLoad() {
    super.viewDidLoad()
    let photo = Photo()
    photo.url = "http://www.griffith.edu.au/__data/assets/image/0019/632332/gu-header-logo.png"

    photos.append(photo)

    // Uncomment the following line to preserve selection between presentations
    // self.clearsSelectionOnViewWillAppear = false

    // Register cell classes
    self.collectionView!.registerClass(PhotoCollectionViewCell.self, forCellWithReuseIdentifier: reuseIdentifier)

    // Do any additional setup after loading the view.
  }

  override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
  }

  override func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
    //#warning Incomplete method implementation -- Return the number of sections
    return 1
  }


  override func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    return photos.count
  }

  override func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCellWithReuseIdentifier(reuseIdentifier, forIndexPath: indexPath) as PhotoCollectionViewCell

    let photo = photos[indexPath.row]
    if let d = photo.data {
      let image = UIImage(data: d)
      cell.imageView.image = image

      photo.url = "\(photo.url)"
      photo.Title = "\(photo.Title)"
    } else {
      photo.loadImage {
        if $0 != nil {
          collectionView.reloadItemsAtIndexPaths([indexPath])
        }
      }
    }
    return cell
  }

  // Uncomment this method to specify if the specified item should be highlighted during tracking
  override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    if let indexPath = sender as? NSIndexPath {
      let photo = photos[indexPath.row]
    }
    if (segue.identifier == "showDetail") {
      if let dvc = segue.destinationViewController as? ViewController {
        let photo = Photo()
        dvc.photo = photo
      }
    }
  }

  override func collectionView(collectionView: UICollectionView, shouldHighlightItemAtIndexPath indexPath: NSIndexPath) -> Bool {
    performSegueWithIdentifier("showDetail", sender: indexPath)
    return true
  }

---

在prepareForSegue方法中，有一行

let photo = Photo()

这将创建一个新的照片对象，它不会获取您在所选单元格中显示的照片对象。您在if-let语句中找到了正确的引用。使用该选项让photo=photos[indexPath.row]

---

至于后退按钮，如果按下新控制器时自动获得后退按钮，则不必编写任何代码来实现该功能。

非常感谢。。谢谢你的回复。但是，当我将照片更改为照片[indexpath.row]时，我的ViewController中的Viewdidload中出现了一个错误。请查看修订，查看所有已更改的内容，以及下次如何提出更好的问题。在和->之间有两条注释需要查看。提出问题时，请确保设置代码格式，并且只包含重现问题所需的代码。您注释掉了很多代码—在提出问题时只需将其删除即可。请在提问时保持代码的格式一致。问题中的空格到处都是，有时将括号{和}放在换行符上，有时放在换行符后面。if-else语句也是如此，有时else位于对应if的}后面，有时使用两个换行符拆分if和else。改进这一点将使您更容易阅读代码并找出错误所在，从而增加有人回答您问题的机会。

let photo = Photo()