Question

我遇到了一个问题，即确定如何检测UIView被触及和UIView被轻击。当它被触及时，我希望UIView改变它的背景颜色。当它被触摸时，我希望UIView执行某些任务。我想知道我是如何解决这个问题的。

-(void)viewDidLoad
{        
    UITapGestureRecognizer *dismissGestureRecognition = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleDismissDoubleTap:)];
    dismissGestureRecognition.numberOfTapsRequired = 1;
    [sectionDismissDoubleView addGestureRecognizer:dismissGestureRecognition];

    UITapGestureRecognizer *dismissGestureDownRecognition = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(dismissGestureDownRecognition:)];
    dismissGestureRecognition.numberOfTouchesRequired = 1;
    [sectionDismissDoubleView addGestureRecognizer:dismissGestureDownRecognition];
}

- (void)handleDismissDoubleTap:(UIGestureRecognizer*)tap {
    SettingsDismissDoubleViewController *settingsDouble = [[SettingsDismissDoubleViewController alloc] initWithNibName:@"SettingsDismissDoubleViewController" bundle:nil];
    [self.navigationController pushViewController:settingsDouble animated:YES];
}

- (void)dismissGestureDownRecognition:(UIGestureRecognizer*)tap {
    NSLog(@"Down");
}

Answer 1

此方法不需要子类化任何东西。您只需向视图添加UILongPressGestureRecognizer并将minimumPressDuration设置为零。然后检查手势事件被调用时的状态，以查看触摸事件是开始还是结束。

以上是上面示例图片的整个项目代码。

import UIKit
class ViewController: UIViewController {

    @IBOutlet weak var myView: UIView!

    override func viewDidLoad() {
        super.viewDidLoad()

        // Add "long" press gesture recognizer
        let tap = UILongPressGestureRecognizer(target: self, action: #selector(tapHandler))
        tap.minimumPressDuration = 0
        myView.addGestureRecognizer(tap)
    }

    // called by gesture recognizer
    func tapHandler(gesture: UITapGestureRecognizer) {

        // handle touch down and touch up events separately
        if gesture.state == .Began {
            myView.backgroundColor = UIColor.darkGrayColor()
        } else if  gesture.state == .Ended {
            myView.backgroundColor = UIColor.lightGrayColor()
        }
    }
}

感谢this answer的想法。

Answer 2

手势识别器可能对你想要的东西有点过分。您可能只想使用-touchesBegan:withEvent:和-touchesEnded:withEvent:的组合。

这是有缺陷的，但它应该会让你知道你想做什么。

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    self.touchDown = YES;
    self.backgroundColor = [UIColor redColor];
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    // Triggered when touch is released
    if (self.isTouchDown) {
        self.backgroundColor = [UIColor whiteColor];
        self.touchDown = NO;
    }
}

- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event
{
    // Triggered if touch leaves view
    if (self.isTouchDown) {
        self.backgroundColor = [UIColor whiteColor];
        self.touchDown = NO;
    }
}

此代码应放在您创建的UIView的自定义子类中。然后使用此自定义视图类型而不是UIView，您将获得触摸处理。

Answer 3

在每个UIControl子类（UIButton等）中，您可以使用它来订阅一组特定的UIControlEvent：

addTarget:action:forControlEvents

您应该为UIControlEventTouchDown添加适当的选择器，为UIControlEventTouchUpInside事件添加另一个目标/选择器。

UIControl reference

Answer 4

感谢Holly's answer我构建了一个ButtonView便利类。

修改：正如answer所说，UILongPressGestureRecognizer反应速度非常快，所以我更新了课程。

用法：

let btn = ButtonView()
btn.onNormal = { btn.backgroundColor = .clearColor() }
btn.onPressed = { btn.backgroundColor = .blueColor() }
btn.onReleased = yourAction // Function to be called

类别：

/** View that can be pressed like a button */

import UIKit

class ButtonView : UIView {

    /* Called when the view goes to normal state (set desired appearance) */
    var onNormal = {}
    /* Called when the view goes to pressed state (set desired appearance) */
    var onPressed = {}
    /* Called when the view is released (perform desired action) */
    var onReleased = {}

    override init(frame: CGRect)
    {
        super.init(frame: frame)

        let recognizer = UILongPressGestureRecognizer(target: self, action: Selector("touched:"))
        recognizer.delegate = self
        recognizer.minimumPressDuration = 0.0
        addGestureRecognizer(recognizer)
        userInteractionEnabled = true

        onNormal()
    }

    func touched(sender: UILongPressGestureRecognizer)
    {
        if sender.state == .Began {
            onPressed(self)
        } else if sender.state == .Ended {
            onNormal(self)
            onReleased()
        }
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

Answer 5

首先，通过您的选择器handleDismissDoubleTap:，我假设您正在寻找双击以解雇。要实现这一目标，您应该这样做：dismissGestureRecognition.numberOfTapsRequired = 2;

其次，如果按下触摸即表示长时间点击（或“点击并按住”）类型的手势，则应使用UILongPressGestureRecognizer代替UITapGestureRecognizer。

iOS检测点击并修改UIView

5 个答案: