Question

我已经搜索过这个问题的解决方案，但在我的案例中找不到任何似乎可以解决的问题。我从UITapGestureRecognizer获得了上述异常。

以下是简化代码：

import UIKit;

class ViewController : UIViewController, UIScrollViewDelegate
{
    @IBOutlet weak var scrollView:UIScrollView!;
    var imageView:UIImageView!;

    override func viewDidLoad()
    {
        super.viewDidLoad();

        ... set up imageView/scrollView here ...

        let doubleTapRecognizer = UITapGestureRecognizer(target: self, action: "onScrollViewDoubleTapped");
        doubleTapRecognizer.numberOfTapsRequired = 2;
        doubleTapRecognizer.numberOfTouchesRequired = 1;
        scrollView.addGestureRecognizer(doubleTapRecognizer);
    }


    func onScrollViewDoubleTapped(recognizer:UITapGestureRecognizer)
    {
    }
}

有人能说出这段代码有什么问题吗？对我来说似乎都是正确的。我怀疑它与将ViewController指定为scrollView的委托（或反之亦然）有关？但是，ViewController被设置为scrollView的委托。但也许它会导致这个错误？

Answer 1

尝试在选择器字符串中添加冒号。

let doubleTapRecognizer = UITapGestureRecognizer(target: self, action: "onScrollViewDoubleTapped:");

正如cabellicar123所提到的，这表明选择器采用了参数。

Answer 2

Swift 4使用#selector。

let tapGesture = UITapGestureRecognizer(target: self, action: #selector(didSelectItem(sender:)))

@objc func didSelectItem(sender: AnyObject?) {
    print("didSelectItem: \(sender)")
}

Answer 3

还可以尝试在方法中添加参数：

...(target: self, action: "yourMethodName:")

func yourMethodName(sender: AnyObject?)
{
    println("Clicked yourMethodName")
}

Answer 4

也许可以帮助某人：我有这个错误，因为我声明了选择器方法的私有性：

func setup() {
  let singleFingerTap = UITapGestureRecognizer(target: self, action: "didTapOnViewInteraction:")
  singleFingerTap.numberOfTapsRequired = 1
  self.viewInteraction.addGestureRecognizer(singleFingerTap)
}

private func didTapOnViewInteraction(recognizer: UITapGestureRecognizer) {

}

删除＆＃34;私人＆＃34;关键字，一切都很棒！

Answer 5

for swift 4

override func viewDidLoad() {
        super.viewDidLoad()

    let tap = UITapGestureRecognizer(target: self, action: #selector(SignUpViewController.click))
    userImage.addGestureRecognizer(tap)
    userImage.isUserInteractionEnabled = true
}

@objc func click()
{
    print("Tapped on Image")
}

其中SignUpViewController是您的viewcontroller名称

Answer 6

在我的情况下，使用Swift 4，选择器被正确定义，但由于带有手势的项目在集合视图中，因此导致无法找到选择器。我实现了一个自定义单元格并在其中配置了选择器

let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "recent", for: indexPath) as! MyCollectionViewCell

cell.configureGestureWith(entry: recentEntries.sorted(by: {$0.createdAt > $1.createdAt})[indexPath.row], sender: self)

希望这对某人有所帮助。

UITapGestureRecognizer无法识别的选择器发送到实例

6 个答案: