仅供参考:我是 Swift 的新手,所以这可能是一个非常简单的问题,但我就是想不通。
我一直在学习使用 Xcode 8 beta 和 Swift 3开始开发 iOS 应用程序 (Swift)教程。
我将 Tap Gesture Recognizer 附加到图像视图,然后在 ViewController.swift 中添加此操作:
@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)
}
当通过点击图像视图调用 selectImageFromPhotLibrary 操作时,应用程序崩溃而不显示 ImagePicker。
我想问题出在新的礼物上,而不是Swift 3 中引入的presentViewController
ViewController.swift
import UIKit
class ViewController: UIViewController, UITextFieldDelegate, UIImagePickerControllerDelegate, UINavigationControllerDelegate {
// MARK: Properties
@IBOutlet weak var mealNameLabel: UILabel!
@IBOutlet weak var nameTextField: UITextField!
@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 : AnyObject]) {
// The info dictionary contains multiple representations of the image, and this uses the original.
let selectedImage = info[UIImagePickerControllerOriginalImage] as! UIImage
// 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"
}
}
控制台输出
2016-06-20 17:08:20.568093 FoodTracker[33322:696094] bundleid: com.armin.FoodTracker, enable_level: 0, persist_level: 0, propagate_with_activity: 0
2016-06-20 17:08:20.569458 FoodTracker[33322:696094] subsystem: com.apple.UIKit, category: HIDEvents, enable_level: 0, persist_level: 0, default_ttl: 0, info_ttl: 0, debug_ttl: 0, generate_symptoms: 0, enable_oversize: 0, privacy_setting: 0
2016-06-20 17:08:20.604909 FoodTracker[33322:696090] Created DB, header sequence number = 288
2016-06-20 17:08:20.668341 FoodTracker[33322:696090] Created DB, header sequence number = 288
2016-06-20 17:08:20.743143 FoodTracker[33322:696090] subsystem: com.apple.BaseBoard, category: MachPort, enable_level: 0, persist_level: 0, default_ttl: 0, info_ttl: 0, debug_ttl: 0, generate_symptoms: 0, enable_oversize: 0, privacy_setting: 0
2016-06-20 17:08:20.769881 FoodTracker[33322:696091] subsystem: com.apple.FrontBoard, category: Common, enable_level: 0, persist_level: 0, default_ttl: 0, info_ttl: 0, debug_ttl: 0, generate_symptoms: 0, enable_oversize: 0, privacy_setting: 0
2016-06-20 17:08:22.007665 FoodTracker[33322:695971] subsystem: com.apple.UIKit, category: Touch, enable_level: 0, persist_level: 0, default_ttl: 0, info_ttl: 0, debug_ttl: 0, generate_symptoms: 0, enable_oversize: 0, privacy_setting: 0
2016-06-20 17:08:22.009799 FoodTracker[33322:695971] subsystem: com.apple.UIKit, category: Gesture, enable_level: 0, persist_level: 0, default_ttl: 0, info_ttl: 0, debug_ttl: 0, generate_symptoms: 0, enable_oversize: 0, privacy_setting: 0
2016-06-20 17:08:22.012973 FoodTracker[33322:695971] subsystem: com.apple.UIKit, category: GestureEnvironment, enable_level: 0, persist_level: 0, default_ttl: 0, info_ttl: 0, debug_ttl: 0, generate_symptoms: 0, enable_oversize: 0, privacy_setting: 0
2016-06-20 17:08:22.013820 FoodTracker[33322:695971] subsystem: com.apple.UIKit, category: GestureExclusion, enable_level: 0, persist_level: 0, default_ttl: 0, info_ttl: 0, debug_ttl: 0, generate_symptoms: 0, enable_oversize: 0, privacy_setting: 0
2016-06-20 17:08:23.061815 FoodTracker[33322:695971] subsystem: com.apple.photos, category: Generic, enable_level: 0, persist_level: 0, default_ttl: 0, info_ttl: 0, debug_ttl: 0, generate_symptoms: 0, enable_oversize: 0, privacy_setting: 0