我试着在用户点击的时候分配一个UIImageView给一个动作。

我知道如何为一个UIButton创建一个动作,但我怎么能模仿一个UIButton相同的行为,但使用一个UIImageView?


当前回答

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,无论何时我们想要添加一个UITapGestureRecognizer到一个UIView或UIView的子类,如UIImageView,我们可以这样做,而不需要为选择器创建相关的函数!

用法:

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

其他回答

你需要添加一个手势识别器(对于点击使用UITapGestureRecognizer,对于点击和按住使用UILongPressGestureRecognizer)到你的UIImageView。

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

并像这样实现selector方法:

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

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
}

(你也可以使用一个UIButton并分配一个图像给它,没有文本,而不是简单地连接一个IBAction)

你可以在UIImageView上面放一个带有透明背景的UIButton,并在加载图像之前监听按钮上的点击

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,无论何时我们想要添加一个UITapGestureRecognizer到一个UIView或UIView的子类,如UIImageView,我们可以这样做,而不需要为选择器创建相关的函数!

用法:

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