Question

我是Swift的初学者，无法弄清楚它崩溃的原因。

模拟器很好（它只是给我一条消息，设备没有相机）但是当我在实际手机上打开它时，应用程序崩溃了。（使用iphone x和11.2.6）
其他所有功能都很好，但相机功能。

我该如何解决？提前谢谢！

import Foundation
import UIKit

class ProductInfoController: UIViewController, 
UIImagePickerControllerDelegate, UINavigationControllerDelegate, 
UITextFieldDelegate {

@IBOutlet weak var productName: UITextField!
@IBOutlet weak var productImage: UIImageView!

var product = Product()

var returningFromPicker = false

override func viewDidLoad() {
    super.viewDidLoad()
    navigationController?.navigationBar.prefersLargeTitles = true
    navigationItem.largeTitleDisplayMode = .always
    navigationController?.navigationBar.largeTitleTextAttributes = [NSAttributedStringKey.foregroundColor : UIColor.white]
    productName.delegate = self
}

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)

    if !returningFromPicker {
        if productName.text == nil {
            productName.text = product.productName
        }

        if productImage.image == nil {
            productImage.image = product.productImage
        }
    }
}

@IBAction func pickImageFromCamera(_ sender: UIButton) {
    chooseImage(fromLibrary: false)
}

@IBAction func pickImageFromLibrary(_ sender: UIButton) {
    chooseImage(fromLibrary: true)
}

@IBAction func onNext(_ sender: UIButton) {
    guard let name = productName.text else {
        showAlert(message: "Provide a product name")
        return
    }

    guard !name.isEmpty else {
        showAlert(message: "Invalid product name provided")
        return
    }

    guard product.productImage != nil else {
        showAlert(message: "Provide a product photo")
        return
    }

    product.productName = name

    if let keywordsVC = storyboard?.instantiateViewController(withIdentifier: "keywordVC") as? KeywordsViewController {
        keywordsVC.product = product
        navigationController?.pushViewController(keywordsVC, animated: true)
    }
}

func textFieldShouldReturn(_ textField: UITextField) -> Bool {
    textField.resignFirstResponder()
    return false
}

func chooseImage(fromLibrary: Bool) {
    let sourceType:UIImagePickerControllerSourceType = fromLibrary ? .photoLibrary:.camera

    guard UIImagePickerController.isSourceTypeAvailable(sourceType) else {
        showAlert(message: "Device doesn't have a " + (fromLibrary ? "Photo Library":"Camera"))
        return
    }

    let imagePicker = UIImagePickerController();
    imagePicker.delegate = self
    imagePicker.allowsEditing = true
    imagePicker.sourceType = sourceType

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

    returningFromPicker = true
}

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
    productImage.image = info[UIImagePickerControllerEditedImage] as? UIImage
    product.productImage = productImage.image
    picker.dismiss(animated: true, completion: nil)
    returningFromPicker = false
}
}

extension UIViewController {
func showAlert(message: String) {
    let alert = UIAlertController(title: "Title", message: message, preferredStyle: .actionSheet)
    alert.addAction(UIAlertAction(title: "OK", style: .cancel, handler: nil))
    present(alert, animated: true, completion: nil)
}
}

Answer 1

您必须在Info.plist中添加以下权限。 Info.plist中的权限

相机：

Key       :  Privacy - Camera Usage Description   
Value     :  $(PRODUCT_NAME) camera use

照片：

Key       :  Privacy - Photo Library Usage Description    
Value     :  $(PRODUCT_NAME) photo use

在Xcode Swift上打开相机时应用程序崩溃

1 个答案: