如何在Swift中为UIImageView对象分配动作

我正在尝试UIImageView在用户点击操作时将其分配给操作。

我知道如何为a创建动作UIButton，但是如何模仿a的相同行为UIButton却使用a UIImageView？

您需要一个UITapGestureRecognizer。要进行设置，请使用以下命令：

override func viewDidLoad()
{
    super.viewDidLoad()

    let tapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(imageTapped(tapGestureRecognizer:)))
    imageView.isUserInteractionEnabled = true
    imageView.addGestureRecognizer(tapGestureRecognizer)
}

@objc func imageTapped(tapGestureRecognizer: UITapGestureRecognizer)
{
    let tappedImage = tapGestureRecognizer.view as! UIImageView

    // Your action
}

（您还可以使用，UIButton并为其分配图片，不添加文字，而只需连接即可IBAction）

您需要在其中添加一个手势识别器（对于轻击，请使用UITapGestureRecognizer；对于轻击并按住，请使用UILongPressGestureRecognizer）UIImageView。

let tap = UITapGestureRecognizer(target: self, action: #selector(YourClass.tappedMe))
imageView.addGestureRecognizer(tap)
imageView.isUserInteractionEnabled = true

并实现选择器方法，例如：

@objc func tappedMe()
{
    println("Tapped on Image")
}

您可以将其添加UITapGestureRecognizer到imageView中，只需将其拖到Storyboard / xib中，将Ctrl从imageView拖动到gestureRecognizer，然后将Ctrl从gestureRecognizer拖动到Swift文件中即可IBAction。

您还需要在上启用用户交互UIImageView，如下图所示：

对于Swift 2.0及更高版本，请执行此操作

@IBOutlet weak var imageView: UIImageView!
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        let tap = UITapGestureRecognizer(target: self, action: #selector(ViewController.tappedMe))
        imageView.addGestureRecognizer(tap)
        imageView.userInteractionEnabled = true
    }
    func tappedMe()
    {
        print("Tapped on Image")
    }

Swift4代码

试试这个新的扩展方法：

import UIKit

extension UIView {

    fileprivate struct AssociatedObjectKeys {
        static var tapGestureRecognizer = "MediaViewerAssociatedObjectKey_mediaViewer"
    }

    fileprivate typealias Action = (() -> Void)?


    fileprivate var tapGestureRecognizerAction: Action? {
        set {
            if let newValue = newValue {
                // Computed properties get stored as associated objects
                objc_setAssociatedObject(self, &AssociatedObjectKeys.tapGestureRecognizer, newValue, objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN)
            }
        }
        get {
            let tapGestureRecognizerActionInstance = objc_getAssociatedObject(self, &AssociatedObjectKeys.tapGestureRecognizer) as? Action
            return tapGestureRecognizerActionInstance
        }
    }


    public func addTapGestureRecognizer(action: (() -> Void)?) {
        self.isUserInteractionEnabled = true
        self.tapGestureRecognizerAction = action
        let tapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(handleTapGesture))
        self.addGestureRecognizer(tapGestureRecognizer)
    }


    @objc fileprivate func handleTapGesture(sender: UITapGestureRecognizer) {
        if let action = self.tapGestureRecognizerAction {
            action?()
        } else {
            print("no action")
        }
    }

}

现在，每当我们想将添加UITapGestureRecognizer到UIView或UIView子类一样UIImageView，我们可以这样做而无需选择创建相关的功能！

用法：

 profile_ImageView.addTapGestureRecognizer {
        print("image tapped")
    }

实际上，您可以将的图片设置为UIButton通常放置在中的图片UIImageView。例如，在哪里可以做：

myImageView.image = myUIImage

您可以改用：

myButton.setImage(myUIImage, forState: UIControlState.Normal)

因此，代码如下所示：

override func viewDidLoad(){
  super.viewDidLoad()

  var myUIImage: UIImage //set the UIImage here
  myButton.setImage(myUIImage, forState: UIControlState.Normal)
}

@IBOutlet var myButton: UIButton!
@IBAction func buttonTap(sender: UIButton!){
  //handle the image tap
}

使用此方法的好处在于，如果必须从数据库中加载图像，则可以在设置图像之前设置按钮的标题：

myButton.setTitle("Loading Image...", forState: UIControlState.Normal)

告诉用户您正在加载图像

需要为TapGestureRecognizer添加懒惰以便注册，
因为如果UITapGestureRecognizer（target：self ...）中的'self'不是惰性变量，则它将为nil。即使您将isUserInteractionEnable = true设置为true，也不会在没有惰性var的情况下进行注册。

lazy var imageSelector : UIImageView = {
    let image = UIImageView(image: "imageName.png")
    //now add tap gesture
    image.isUserInteractionEnabled = true
    image.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(handleImageSelector)))
    return image
}()
@objc private func handleImageSelector() {
    print("Pressed image selector")
}

您可以UIButton在的顶部放置一个具有透明背景的UIImageView，并在加载图像之前先听一下按钮的轻触

Swift 4代码

步骤1在ViewdidLoad（）中

   let pictureTap = UITapGestureRecognizer(target: self, action: #selector(MyInfoTableViewController.imageTapped))
       userImageView.addGestureRecognizer(pictureTap)
       userImageView.isUserInteractionEnabled = true

步骤2添加以下功能

@objc func imageTapped() {

        let imageView = userImageView
        let newImageView = UIImageView(image: imageView?.image)
        newImageView.frame = UIScreen.main.bounds
        newImageView.backgroundColor = UIColor.black
        newImageView.contentMode = .scaleAspectFit
        newImageView.isUserInteractionEnabled = true
        let tap = UITapGestureRecognizer(target: self, action: #selector(dismissFullscreenImage))
        newImageView.addGestureRecognizer(tap)
        self.view.addSubview(newImageView)

        self.navigationController?.isNavigationBarHidden = true
        self.tabBarController?.tabBar.isHidden = true

    }

经过测试，可以正常工作

我建议将不可见（不透明度= 0）按钮放在imageview上，然后处理按钮上的交互。