向 uiimage 添加手势识别器

adding gesture recognizer to uiimage

我有图像滑块..我按照本教程进行操作:Create a Horizontal Paging UIScrollView with UIPageControl Swift 4 XCode 9并且效果很好..

现在我想在这些图像上添加手势识别器..我试着这样做:

func createSlides() -> [banner] {

    let tapGesture = UITapGestureRecognizer(target: self, action: #selector(tapped))
    tapGesture.numberOfTapsRequired = 1
    tapGesture.numberOfTouchesRequired = 1

    let slide1:banner = Bundle.main.loadNibNamed("banner", owner: self, options: nil)?.first as! banner
    slide1.img.image = UIImage(named: "bannerex")
    slide1.img.addGestureRecognizer(tapGesture)

    let slide2:banner = Bundle.main.loadNibNamed("banner", owner: self, options: nil)?.first as! banner
    slide2.img.image = UIImage(named: "bannerex")
    slide2.img.addGestureRecognizer(tapGesture)

    let slide3:banner = Bundle.main.loadNibNamed("banner", owner: self, options: nil)?.first as! banner
    slide3.img.image = UIImage(named: "bannerex")
    slide3.img.addGestureRecognizer(tapGesture)

    return [slide1, slide2, slide3]
}

@objc func tapped(_ sender: UITapGestureRecognizer){
    print("tapped")
    print(pageControl.currentPage)
}

但它不起作用,不会发生任何事情。

如何解决这个问题?

import UIKit

class banner: UIView {


@IBOutlet weak var img: UIImageView!

 }

Image views 默认忽略用户事件。如果您希望图像视图也处理用户交互,请将其 isUserInteractionEnabled 属性 的值更改为 true。

UITapGestureRecognizer 只能与单个视图一起使用,因此如果要检测每个 image 上的点击,则需要为每个图像创建不同的 UITapGestureRecognizer。阅读更多 HERE.

你需要为每个 imageView 设置 isUserInteractionEnabledtrue

这里有两个问题:

  1. isUserInteractionEnabled默认为false
  2. 您必须为每个图像视图分配一个单独的手势识别器

解决方案

我建议不要将每个图像视图的 isUserInteractionEnabled 设置为 true,而是将该代码放在 Banner class 本身中。由于您似乎是从情节提要中初始化它,因此使用 awakeFromNib 函数应该可以正常工作:

class Banner: UIView {

    @IBOutlet weak var img: UIImageView!

    override func awakeFromNib() {
        super.awakeFromNib()
        img.isUserInteractionEnabled = true
    }
 }

在您的 createSlides() 函数中,为每个视图添加一个单独的点击手势:

let slide1:banner = Bundle.main.loadNibNamed("banner", owner: self, options: nil)?.first as! banner
slide1.img.image = UIImage(named: "bannerex")
slide1.img.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(tapped)))

甚至更好的缩放和无代码冗余:

function tap() -> UITapGestureRecognizer {
    return UITapGestureRecognizer(target: self, action: #selector(tapped))
}

let slide1:banner = Bundle.main.loadNibNamed("banner", owner: self, options: nil)?.first as! banner
slide1.img.image = UIImage(named: "bannerex")
slide1.img.addGestureRecognizer(tap())