ios 如何在 Swift 中为 UIImageView 对象分配一个动作

How to assign an action for UIImageView object in Swift

提问by user3706773

I'm trying to assign an UIImageViewto an action when the user taps it.

UIImageView当用户点击它时，我试图为它分配一个动作。

I know how to create an action for a UIButton, but how could I mimic the same behavior of a UIButton, but using a UIImageView?

我知道如何为 a 创建一个动作UIButton，但是我怎么能模仿 a 的相同行为UIButton，但是使用 aUIImageView呢？

回答by Aseider

You'll need a UITapGestureRecognizer. To set up use this:

你需要一个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
}

(You could also use a UIButtonand assign an image to it, without text and than simply connect an IBAction)

（你也可以使用 aUIButton并为其分配一个图像，没有文本，而不是简单地连接一个IBAction）

回答by Midhun MP

You need to add a a gesture recognizer (For tap use UITapGestureRecognizer, for tap and hold use UILongPressGestureRecognizer) to your UIImageView.

您需要添加AA手势识别（对于自来水的使用UITapGestureRecognizer，为点住用UILongPressGestureRecognizer）到您UIImageView。

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

And Implement the selector method like:

并实现选择器方法，如：

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

回答by Emil

You can add a UITapGestureRecognizerto the imageView, just drag one into your Storyboard/xib, Ctrl-drag from the imageView to the gestureRecognizer, and Ctrl-drag from the gestureRecognizer to the Swift-file to make an IBAction.

您可以向UITapGestureRecognizerimageView添加一个，只需将一个拖到您的 Storyboard/xib 中，按住 Ctrl 从 imageView 拖动到gestureRecognizer，然后按住 Ctrl 从gestureRecognizer 拖动到 Swift 文件以制作IBAction.

You'll also need to enable user interactions on the UIImageView, as shown in this image:

您还需要在 上启用用户交互UIImageView，如下图所示：

回答by Abhishek Kumar

For swift 2.0 and above do this

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")
    }

回答by Ravindra_Bhati

Swift4 Code

Swift4 代码

Try this some new extension methods:

试试这个一些新的扩展方法：

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")
        }
    }

}

Now whenever we want to add a UITapGestureRecognizerto a UIViewor UIViewsubclass like UIImageView, we can do so without creating associated functions for selectors!

现在，无论何时我们想要将 a 添加UITapGestureRecognizer到 aUIView或UIView子类 like UIImageView，我们都可以在不为选择器创建关联函数的情况下这样做！

Usage:

用法：

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

回答by Jojodmo

You could actually just set the image of the UIButtonto what you would normally put in a UIImageView. For example, where you would do:

实际上，您可以将 的图像设置为UIButton通常放在UIImageView. 例如，你会在哪里做：

myImageView.image = myUIImage

You could instead use:

您可以改为使用：

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

So, here's what your code could look like:

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
}

The great thing about using this method is that if you have to load the image from a database, you could set the title of the button before you set the image:

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

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

To tell your users that you are loading the image

告诉您的用户您正在加载图像

回答by candyline

Need to add lazy for TapGestureRecognizer to register
since the 'self' in UITapGestureRecognizer(target: self ...) will be nil if it's not a lazy var. Even if you set isUserInteractionEnable = true, it won't register without lazy var.

需要为 TapGestureRecognizer 添加惰性以进行注册，
因为 UITapGestureRecognizer(target: self ...) 中的 'self' 如果不是惰性变量，则为零。即使您设置 isUserInteractionEnable = true，它也不会在没有惰性变量的情况下注册。

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")
}

回答by Sachin Rasane

Swift 4 Code

斯威夫特 4 代码

---

---

Step 1 In ViewdidLoad()

第 1 步在 ViewdidLoad()

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

Step 2 Add Following Function

Step 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

    }

It's Tested And Working Properly

它已经过测试并且工作正常

回答by depsch ali

You can put a UIButtonwith a transparent background over top of the UIImageView, and listen for a tap on the button before loading the image

您可以UIButton在 顶部放置一个带有透明背景的UIImageView，并在加载图像之前聆听按钮上的点击

回答by levan

I suggest to place invisible(opacity = 0) button on your imageview and then handle interaction on button.

我建议在您的图像视图上放置不可见（不透明度 = 0）按钮，然后处理按钮上的交互。