如何允许用户使用Swift选择图像？

Question

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。

Answer 1

如果只想让用户使用UIImagePickerController选择图像，请使用以下代码：

import UIKit


class ViewController: UIViewController, UINavigationControllerDelegate, UIImagePickerControllerDelegate {

    @IBOutlet var imageView: UIImageView!
    @IBOutlet var chooseBuuton: UIButton!
    var imagePicker = UIImagePickerController()

    @IBAction func btnClicked() {

        if UIImagePickerController.isSourceTypeAvailable(.savedPhotosAlbum){
            print("Button capture")

            imagePicker.delegate = self
            imagePicker.sourceType = .savedPhotosAlbum
            imagePicker.allowsEditing = false

            present(imagePicker, animated: true, completion: nil)
        }
    }

    func imagePickerController(picker: UIImagePickerController!, didFinishPickingImage image: UIImage!, editingInfo: NSDictionary!){
        self.dismiss(animated: true, completion: { () -> Void in

        })

        imageView.image = image
    }
}