我正在用Swift编写我的第一个iOS应用程序（仅iPhone）。主应用程序视图应允许用户从相册中选择图像。

我找到了以下 ViewController.swift 示例代码：

class ViewController: UIImagePickerController, UINavigationControllerDelegate, UIImagePickerControllerDelegate  {

    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 tableView(tableView: UITableView!, didSelectRowAtIndexPath indexPath: NSIndexPath!) {

        var imagePickerController = UIImagePickerController()
        imagePickerController.delegate = self
        imagePickerController.sourceType = UIImagePickerControllerSourceType.SavedPhotosAlbum
        imagePickerController.allowsEditing = true
        self.presentViewController(imagePickerController, animated: true, completion: { imageP in

        })
    }


    func imagePickerController(picker: UIImagePickerController!, didFinishPickingImage image: UIImage!, editingInfo: NSDictionary!) {
        let selectedImage : UIImage = image
        println(selectedImage)
    }

}

并具有以下View Controller Scene-

View Controller
 - Top Layout Guide
 - Bottom Layout Guide
 - View
   - Image View
First Responder
Exit

但是，当我启动该应用程序时，仅显示黑屏。我做错了什么？我发现的另一个示例代码是在Objective-C中，这对我没有帮助。