如何在 Swift 中为 UIImageView 对象分配动作

Question

我正在尝试将 UIImageView 分配给用户点击操作时的操作。

我知道如何为 UIButton 创建一个动作，但我如何模仿 UIButton 的相同行为，但使用 UIImageView？

Answer 1

您需要为您的 UIImageView 添加一个手势识别器（用于点击 UITapGestureRecognizer, for tap and hold use UILongPressGestureRecognizer）。

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

并像这样实现选择器方法：

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

Answer 2

您需要 UITapGestureRecognizer。要设置使用这个：

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
}

（您也可以使用 UIButton 并为其分配图像，不带文本，而不仅仅是连接 IBAction）

Answer 3

您实际上可以将 UIButton 的图像设置为您通常在 UIImageView 中放置的图像。例如，你会在哪里做：

myImageView.image = myUIImage

您可以改用：

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

因此，您的代码可能如下所示：

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，如果您必须从数据库加载图像，您可以在设置图像之前设置按钮的标题：

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

告诉您的用户您正在加载图片

Answer 4

您可以添加一个 UITapGestureRecognizer 到 imageView，只需将一个拖入您的 Storyboard/xib，Ctrl-drag 从 imageView 拖到 gestureRecognizer，Ctrl-drag 从 gestureRecognizer到 Swift-file 做一个 IBAction.

您还需要在 UIImageView 上启用用户交互，如下图所示：

Answer 5

您可以在 UIImageView 上方放置一个具有透明背景的 UIButton，并在加载图像之前聆听点击按钮的声音

Answer 6

对于 Swift 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.isUserInteractionEnabled = true
}

func tappedMe() {
    print("Tapped on Image")
}

Answer 7

Swift4码

ViewdidLoad() 中的第 1 步

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

第 2 步添加以下功能

@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

    }

它已经过测试并且工作正常

Answer 8

Swift4 代码

尝试一些新的扩展方法：

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，每当我们想要将 UITapGestureRecognizer 添加到 UIView 或 UIView 子类（如 UIImageView）时，我们都可以在不为选择器创建关联函数的情况下这样做！

用法：

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

Answer 9

我建议将 invisible(opacity = 0) 按钮放在您的 imageview 上，然后处理按钮上的交互。

Answer 10

需要为TapGestureRecognizer添加lazy才能注册
因为 UITapGestureRecognizer(target: self ...) 中的 'self' 如果不是惰性变量，则将为 nil。即使您设置 isUserInteractionEnable = true，如果没有惰性变量，它也不会注册。

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")
}

Answer 11

这是我发现的，设置起来更容易。

Here is the YouTube video

打开库，查找“点击手势识别器”对象。
将对象拖到情节提要中，然后将委托设置为要触发动作的图像。
然后转到视图控制器，拖动相同的对象以设置 IBAction。

Answer 12

@IBOutlet weak var imageView: UIImageView!

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
//ViewController is your current view controller    
let tap = UITapGestureRecognizer(target: self, action: #selector(ViewController.tappedMe))
    imageView.addGestureRecognizer(tap)
    imageView.isUserInteractionEnabled = true
}

// Need to ass objective-c annotation 
@objc
func tappedMe() {
    print("Tapped on Image")
}

如何在 Swift 中为 UIImageView 对象分配动作

How to assign an action for UIImageView object in Swift

ios

swift

uiimageview

Swift4码

ViewdidLoad() 中的第 1 步

第 2 步添加以下功能

它已经过测试并且工作正常