iphone - UITapGestureRecognizer 在 UIImageView 中不起作用

Question

我有以下代码：

UITapGestureRecognizer *showStoryTapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(showNewsStory:)];
[showStoryTapRecognizer setDelegate:self];
[self.storyImageView_ addGestureRecognizer:showStoryTapRecognizer];
[showStoryTapRecognizer release];

然而，这不会触发 showNewsStory，这是为什么呢？我在图像视图中启用了 userInteraction。

Answer 1

UIImageView您应该为对象启用用户交互：

[self.storyImageView_ setUserInteractionEnabled:YES];

---

编辑：

尝试删除

[showStoryTapRecognizer setDelegate:self];

UITapGestureRecognizer据我所知，我 认为没有它的委托方法。

Answer 2

UITapGestureRecognizer *oneTouch=[[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(OneTouchHandeler)];

[oneTouch setNumberOfTouchesRequired:1];

[imageView addGestureRecognizer:oneTouch];

imageView.userInteractionEnabled = YES;

Answer 3

UIImageViewUIView与UIKit 中的大多数其他子类不同，默认情况下禁用用户交互。

Answer 4

我还注意到，在 swift3 中，如果您要添加一个手势识别器，该手势识别器也会查找目标并且目标通常是self，那么您必须将要添加手势识别器的 UIView 设置为lazy var. 否则手势识别器将无法工作。我认为这是swift3中的一个错误。理想情况下，如果您在类完全初始化之前访问变量中的 self，它应该会引发错误。下面的代码不会检测手势识别器。

let messageImageView: CachedImageView = {
    let iv = CachedImageView()
    iv.translatesAutoresizingMaskIntoConstraints = false
    iv.layer.cornerRadius = 16
    iv.layer.masksToBounds = true
    iv.contentMode = .scaleAspectFill
    iv.isUserInteractionEnabled = true
    let zoomTap = UITapGestureRecognizer(target: self, action: #selector(handleZoomTap))
    zoomTap.numberOfTapsRequired = 1
    iv.addGestureRecognizer(zoomTap)
    return iv
}()

要解决这个问题，你必须使用lazy var

lazy var messageImageView: CachedImageView = {
    let iv = CachedImageView()
    iv.translatesAutoresizingMaskIntoConstraints = false
    iv.layer.cornerRadius = 16
    iv.layer.masksToBounds = true
    iv.contentMode = .scaleAspectFill
    iv.isUserInteractionEnabled = true
    let zoomTap = UITapGestureRecognizer(target: self, action: #selector(handleZoomTap))
    zoomTap.numberOfTapsRequired = 1
    iv.addGestureRecognizer(zoomTap)
    return iv
}()

Answer 5

也许......action:@selector(showNewsStory)而不是 action:@selector(showNewsStory:) 。请检查一下 。UITapGestureRecognizer这个控制器里还有其他的吗？尝试这个：

otherTapRecognizer.cancelsTouchesInView = NO;

Answer 6

目标c ios 10

UITapGestureRecognizer *oneTouch=[[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(OneTouchHandeler)];

[oneTouch setNumberOfTouchesRequired:1];

[imageView addGestureRecognizer:oneTouch];

imageView.userInteractionEnabled = YES;

// 快速 3.0

   let oneTouch = UITapGestureRecognizer(target: self, action: #selector(self.OneTouchHandeler(_:)))

imageView.addGestureRecognizer(oneTouch)

imageView.isUserInteractionEnabled = true

Answer 7

如果您已经设置imageView.userInteractionEnabled = YES;但操作仍然没有触发。也许是因为 imageView userInteractionEnabled 的超级视图之一是 NO；

Answer 8

添加

storyImageView.isUserInteractionEnabled = true;

Answer 9

    use lazy var instead of let . Here is an example.

    lazy var loginSignUpView: LoginSignUpView = {
            let lsv = LoginSignUpView()
            lsv.loginRegisterButton.addTarget(self, action: #selector(handleLoginRegistrationButton), for: .touchUpInside)
            lsv.segmentedControlForLoginRegister.addTarget(self, action: #selector(handleSegmentedControlForLoginRegister), for: .valueChanged)
            lsv.profileImageView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(handleSelectProfileImageView)))

            return lsv
        }()


@objc func handleSelectProfileImageView() {
        print("Image tapped")
    }

Answer 10

如果您允许 2 种不同的手势，您应该添加下面的代码片段。例如，您使用 pickerView 并且还想检测相同 pickerView 的点击手势。

询问代理是否应允许两个手势识别器同时识别手势。

目标 C

    -(BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer{
    return true;
}

迅速

func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
    return true
}