iOS - 在图像视图上点击手势问题 [英] iOS - Tap Gesture issue on image view

问题描述

我正在慢慢学习 Apple 的 Swift 开发学习，但我的点击手势一直遇到问题.我重新创建了项目编号，结果都相同.

I am slowly working my way through Apple's learn developing for Swift and I keep running into an issue with my tap gesture. I have re-created the project numbers times all with the same outcome.

我向图像视图添加了点击手势，这应该会从我的计算机打开照片库.什么都没发生.

I add a tap gesture to an image view and this should open the photo library from my computer. Nothing happens.

当我从 Apple 下载并运行示例文件时，一切正常.当我将 Apple 的代码复制并粘贴到我的代码时，同样没有任何反应.我已经经历了我能做的一切，但觉得我错过了一些东西.

When I download and run the sample file from Apple everything works. When I copy and paste the code from Apple's to mine, again, nothing happens. I have gone through everything that I can but feel that I am missing something.

这是我的代码.苹果的代码如下:

Here is my code. Apple's code is below:

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()

        // handle the text fields user input through delegate callbacks
        nameTextField.delegate = self

    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    // 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 user cancels
        dismissViewControllerAnimated(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 the photoviewimage to be the selected image
        photoImageView.image = selectedImage

        // Dismiss the picker
        dismissViewControllerAnimated(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 pictures to be selected and not taken
        imagePickerController.sourceType = .PhotoLibrary

        // make sure the viewcontroller is notified when the user selects an image
        imagePickerController.delegate = self

        presentViewController(imagePickerController, animated: true, completion: nil)

    }

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

}

这是苹果的代码:

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()

        // 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.
        dismissViewControllerAnimated(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.
        dismissViewControllerAnimated(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

        presentViewController(imagePickerController, animated: true, completion: nil)
    }

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

}

Anbu 的工作代码

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() {
        let tapgesture = UITapGestureRecognizer(target: self, action: Selector("imagepressed"))
        photoImageView.userInteractionEnabled = true
        photoImageView.addGestureRecognizer(tapgesture)

        super.viewDidLoad()

        // handle the text fields user input through delegate callbacks
        nameTextField.delegate = self

    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    // 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 user cancels
        dismissViewControllerAnimated(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 the photoviewimage to be the selected image
        photoImageView.image = selectedImage

        // Dismiss the picker
        dismissViewControllerAnimated(true, completion: nil)
    }

    // MARK: Actions


    func imagepressed () {
        nameTextField.resignFirstResponder()

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

        // Only Allow pictures to be selected and not taken
        imagePickerController.sourceType = .PhotoLibrary

        // make sure the viewcontroller is notified when the user selects an image
        imagePickerController.delegate = self

        presentViewController(imagePickerController, animated: true, completion: nil)
    }



/*    @IBAction func selectImageFromPhotoLibrary(sender: UITapGestureRecognizer) {
        let tapgesture = UITapGestureRecognizer(target: self, action: Selector("imagepressed"))
        photoImageView.userInteractionEnabled = true
        photoImageView.addGestureRecognizer(tapgesture)

        // 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 pictures to be selected and not taken
        imagePickerController.sourceType = .PhotoLibrary

        // make sure the viewcontroller is notified when the user selects an image
        imagePickerController.delegate = self

        presentViewController(imagePickerController, animated: true, completion: nil)

    }
   */

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

}

推荐答案

do like

原因，UIImageview userInteraction默认为false，需要手动开启

The reason ,by default the UIImageview userInteraction is false, so you need to enable manually

第一步

let tapGesture = UITapGestureRecognizer(target:self, action:Selector("imagePressed"))
photoImageView.userInteractionEnabled = true // this line is important
photoImageView.addGestureRecognizer(tapGesture)

第 2 步

func imagePressed()
{
//do  Your action here  whatever you want 
}

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