Apple iOS开发指南中应该没有问题

Question

我今天开始使用Apple's Official Guide for Swift Development开始学习iOS开发。

我已到达Work with View Controllers。在页面结尾之前有一个检查点，我应该在模拟器上运行应用程序，当我单击图像视图时，我应该得到SIGABRT错误，因为我没有显示图像的权限

不仅我没有收到任何错误消息，单击图像视图时根本没有任何反应。

我已经检查过3次文件，以确保我没有错过任何内容。我甚至创建了一个新项目，以确保一切正常，但仍然无法正常工作。

ViewController.swift：

import UIKit

class ViewController: UIViewController, UITextFieldDelegate, UIImagePickerControllerDelegate, UINavigationControllerDelegate {

//MARK: Properties
@IBOutlet weak var nameTextField: UITextField!
@IBOutlet weak var mealNameLabel: UILabel!
@IBOutlet weak var photoImageView: UIImageView!

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.

    // Handle the text field's user input through delegate callbacks.
    nameTextField.delegate = self
}

//MARK: UITextFieldDelegate
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
    // Hide the keyboard.
    textField.resignFirstResponder()

    return true
}

func textFieldDidEndEditing(_ textField: UITextField) {
    mealNameLabel.text = textField.text
}

//MARK: UIImagePickerControllerDelegate
func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
    // Dismiss the picker if the user canceled.
    dismiss(animated: true, completion: nil)
}

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
    // The info dictionary may contain multiple representations of the image. You want to use the original.
    guard let selectedImage = info[UIImagePickerControllerOriginalImage] as? UIImage else {
        fatalError("Expected a dictionary containing an image, but was provided the following: \(info)")
    }

    // Set photoImageView to display the selected image.
    photoImageView.image = selectedImage

    // Dismiss the picker.
    dismiss(animated: true, completion: nil)
}

//MARK: Actions
@IBAction func selectImageFromPhotoLibrary(_ sender: UITapGestureRecognizer) {
    // Hide the keyboard.
    nameTextField.resignFirstResponder()

    // UIImagePickerController is a view controller that lets a user pick media from their photo library.
    let imagePickerController = UIImagePickerController()

    // Only allow photos to be picked, not taken.
    imagePickerController.sourceType = .photoLibrary

    // Make sure ViewController is notified when the user picks an image.
    imagePickerController.delegate = self
    present(imagePickerController, animated: true, completion: nil)
}

@IBAction func setDefaultLabelText(_ sender: UIButton) {
    mealNameLabel.text = "Default Text"
}
}

Main.storyboard：

你能帮我解决一下吗？

Answer 1

当您尝试在未经许可的情况下访问相机胶卷时，应该会发生此错误。

iOS 10要求您添加关于您想要访问相机胶卷的原因的说明。这需要使用密钥Privacy - Photo Library Usage Description

添加到info.plist文件中

如果您没有收到此错误，我猜您已经在我们在旧版iOS上运行的plist文件中输入了此信息？或者访问相机胶卷的代码实际上没有触发，您可能需要点击屏幕或按下按钮来启动代码。

Answer 2

我正在使用Tap Gesture Recognizer，我使用Storyboard放置在UIImage上。

为了实现这一点，我还必须在故事板中UIImage的属性检查器中标记为“启用用户交互”的块中放置一个复选标记。