如何在我的应用程序中实现UITapGestureRecognizer

Question

我对编程和目标C都很陌生.我想知道如何制作一个有空白屏幕和计时器一分钟的应用程序.你的意思是尽可能快地点击,只要你可以.我想知道如何实现UITapGestureRecognizer我的代码.

Answer 1

这是关于如何在班级中实现手势识别器的分步指南:

1. 使您的班级符合UIGestureRecognizerDelegate协议.

2. 实例化手势识别器.例如,要实例化a UITapGestureRecognizer,我们将:

   UITapGestureRecognizer *tapGestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTapFrom:)];
   

   这里,action是处理手势的选择器.在这里,我们的选择器handleTapFrom将如下所示:

   - (void) handleTapFrom: (UITapGestureRecognizer *)recognizer
   {
       //Code to handle the gesture
   }
   

   选择器的参数是手势识别器.我们可以使用这个手势识别器来访问它的属性,例如,我们可以发现手势识别的状态,如,UIGestureRecognizerStateBegan,UIGestureRecognizerStateEnded,等.

3. 在实例化的手势识别器上设置所需的属性.例如,对于a UITapGestureRecognizer,我们可以设置属性numberOfTapsRequired,和numberOfTouchesRequired.

4. 将手势识别器添加到要检测手势的视图中.在我们的示例代码中(我将分享该代码供您参考),我们将使用以下代码行向imageView添加手势识别器:

   [self.imageView addGestureRecognizer:tapGestureRecognizer];
   

5. 将手势识别器添加到视图后,设置手势识别器的委托,即将处理所有手势识别器内容的类.在我们的示例代码中,它将是:

   tapGestureRecognizer.delegate = self;
   

   注意:将手势识别器添加到视图后分配代理.否则,将不会调用action方法.

Answer 2

UITapGestureRecognizer *gestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(hideKeyboard)];
[self.tableView addGestureRecognizer:gestureRecognizer];
self.tableView.userInteractionEnabled = YES;
gestureRecognizer.cancelsTouchesInView = NO;  // this prevents the gesture recognizers to 'block' touches

Answer 3

Swift中的示例:

import UIKit

class ViewController: UIViewController {

    @IBOutlet var myUIImageView: UIImageView!

    override func viewDidLoad() {
        super.viewDidLoad()

        let singleTap: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: "myUIImageViewTapped:")
        singleTap.numberOfTapsRequired = 1
        singleTap.numberOfTouchesRequired = 1
        self.myUIImageView.addGestureRecognizer(singleTap)
        self.myUIImageView.userInteractionEnabled = true
    }

    func myUIImageViewTapped(recognizer: UITapGestureRecognizer) {
        if(recognizer.state == UIGestureRecognizerState.Ended){
            println("myUIImageView has been tapped by the user.")
        }
    }

}