swift - 快速将UIImage推送到下一个 View Controller

我已经成功地将图像解析为cellForRowAt，但是现在需要为didSelectRowAt的ResultsViewController中的配方将其显示为downloadImage，并且遇到了麻烦。

RecipeTableViewController.swift

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! RecipeTableViewCell

    if let item = tableViewDataSource[indexPath.item] as? Recipe {
        if isSearching {
            cell.item = filteredData[indexPath.row]
            cell.recipeImage.downloadImage(from: (self.filteredData[indexPath.item].image))
        } else {
            cell.item = item
            cell.recipeImage.downloadImage(from: (self.tableViewDataSource[indexPath.item].image))
        }
    }

    return cell
}

override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
    let Storyboard = UIStoryboard(name: "Main", bundle: nil)
    let resultsVC = Storyboard.instantiateViewController(withIdentifier: "ResultsViewController") as! ResultsViewController

    // Information to be passed to ResultsViewController

    if (tableViewDataSource[indexPath.item] as? Recipe) != nil {
        if isSearching {
            resultsVC.getTitle = filteredData[indexPath.row].title
            resultsVC.getIngredients = filteredData[indexPath.row].ingredients
            // Parse Image
        } else {
            resultsVC.getTitle = tableViewDataSource[indexPath.row].title
            resultsVC.getIngredients = tableViewDataSource[indexPath.row].ingredients
            // Parse Image
            //resultsVC.getImage = resultsVC.imageDisplay.downloadImage(from (self.tableViewDataSource[indexPath.item].image))
        }
    }
    // Push to next view
    self.navigationController?.pushViewController(resultsVC, animated: true)

}

extension UIImageView {
func downloadImage(from url: String) {
    let urlRequest = URLRequest(url: URL(string: url)!)
    let task = URLSession.shared.dataTask(with: urlRequest) { (data,response,error) in
        if error != nil {
            print(error!)
            return
        }
        DispatchQueue.main.sync {
            self.image = UIImage(data: data!)
        }
    }
    task.resume()
}
}

ResultsViewController.swift

class ResultsViewController: UIViewController {

    var getTitle = String()
    var getIngredients = String()
    var getImage = String()

    @IBOutlet weak var recipeDisplay: UILabel!
    @IBOutlet weak var ingredientsDisplay: UITextView!
    @IBOutlet weak var imageDisplay: UIImageView!

    override func viewDidLoad() {
        super.viewDidLoad()

        recipeDisplay.text! = getTitle
        ingredientsDisplay.text! = getIngredients
        imageDisplay.image! = getImage
    }
    ...
}

我可以在cellForRowAt中调用didSelectRowAt函数，但无法找出将图像推送到下一个视图控制器的方法。 中有注释的代码，该代码返回错误：


  “无法将类型'（）'的值分配给类型'UIImage'”


感谢帮助。

最佳答案

将didSelectRowAt替换为以下内容，

override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
 let Storyboard = UIStoryboard(name: "Main", bundle: nil)
 let resultsVC = Storyboard.instantiateViewController(withIdentifier: "ResultsViewController") as! ResultsViewController

 // Information to be passed to ResultsViewController

 if (tableViewDataSource[indexPath.item] as? Recipe) != nil {
     if isSearching {
         resultsVC.getTitle = filteredData[indexPath.row].title
         resultsVC.getIngredients = filteredData[indexPath.row].ingredients
        // Parse Image
        resultsVC.getImage = filteredData[indexPath.item].image
     } else {
         resultsVC.getTitle = tableViewDataSource[indexPath.row].title
         resultsVC.getIngredients = tableViewDataSource[indexPath.row].ingredients
         // Parse Image
         resultsVC.getImage = self.tableViewDataSource[indexPath.item].image
     }
 }
 // Push to next view
 self.navigationController?.pushViewController(resultsVC, animated: true)

}

然后像这样更新ResultsViewController

class ResultsViewController: UIViewController {

    var getTitle = String()
    var getIngredients = String()
    var getImage = String()

    @IBOutlet weak var recipeDisplay: UILabel!
    @IBOutlet weak var ingredientsDisplay: UITextView!
    @IBOutlet weak var imageDisplay: UIImageView!

    override func viewDidLoad() {
        super.viewDidLoad()

        recipeDisplay.text = getTitle
        ingredientsDisplay.text = getIngredients
        imageDisplay.downloadImage(from: getImage)
    }
    ...
}

另外，确保在IBOutlets中连接了storyboard