成为第一响应者后，添加到文本字段的 Swift 手势识别器无法操作？

Question

我在 swift 中向文本字段添加了点击和双击手势识别器，因此单击执行功能但双击实际上使文本字段成为第一响应者。虽然在文本字段第一次成为第一响应者后它停止工作。也就是说，文本字段通过单击而不是双击成为第一响应者来正常运行。关于如何让我的手势识别器正常工作有什么想法吗？

Answer 1

另一种方法:

只需在文本字段顶部创建一个“不可见” View 并向其添加手势识别器即可

    import UIKit

    class ViewController: UIViewController, UITextFieldDelegate {

        @IBOutlet weak var textField: UITextField!

        override func viewDidLoad() {
            super.viewDidLoad()
            textField.delegate = self;
        }

        override func viewDidAppear(animated: Bool) {
            let tap1 = UITapGestureRecognizer(target: self, action: "onSingleTap")
            let tap2 = UITapGestureRecognizer(target: self, action: "onDoubleTap")
            tap2.numberOfTapsRequired = 2

            // create a view and put it on top of the textfield
            // here created at viewDidAppear for example but you can do it better

            var dummieView = UIView(frame: self.textField.frame)
            dummieView.backgroundColor = UIColor(red: 1.0, green: 0.0, blue: 0.0, alpha: 0.25)
            self.view.addSubview(dummieView)
            dummieView.addGestureRecognizer(tap1)
            dummieView.addGestureRecognizer(tap2)
        }

        func onSingleTap(){
            println("custom single tap")
            if self.textField.isFirstResponder() {
                self.textField.resignFirstResponder()
            }
        }

        func onDoubleTap(){
            println("double tap")
            self.textField.becomeFirstResponder()
        }

        func textFieldShouldReturn(textField: UITextField) -> Bool {
            if self.textField.isFirstResponder() {
                self.textField.resignFirstResponder()
            }
            return true
        }


    }