iOS/Swift:如何检测UITextField上的触摸操作

Question

我想检测UITextField上的触摸操作.

看起来"触摸内部"动作不是通过触摸文本字段内部来触发的.

Answer 1

似乎UiTextField没有启用"Touch Up Inside",但"Touch Down"可以正常工作.

所以解决方案如下:

myTextField.addTarget(self, action: #selector(myTargetFunction), for: .touchDown)
@objc func myTargetFunction(textField: UITextField) {
    print("myTargetFunction")
}

Answer 2

斯威夫特4:

class ViewController: UIViewController, UITextFieldDelegate {
    func textFieldDidBeginEditing(_ textField: UITextField) {
        if textField == myTextField {
            print("You edit myTextField")
        }
    }
}

这是一个委托功能.

Answer 3

这是Swfit:

并且您不需要使用"touchUpInside"只需使用委托方法,如下所示:

使您的View控制器成为委托:

class ViewController: UIViewController, UITextFieldDelegate{

func textFieldDidBeginEditing(textField: UITextField) -> Bool {
    if textField == myTextField {
        return true // myTextField was touched
    }
}

这是其他委托方法:

protocol UITextFieldDelegate : NSObjectProtocol {

    optional func textFieldShouldBeginEditing(textField: UITextField) -> Bool // return NO to disallow editing.
    optional func textFieldDidBeginEditing(textField: UITextField) // became first responder
    optional func textFieldShouldEndEditing(textField: UITextField) -> Bool // return YES to allow editing to stop and to resign first responder status. NO to disallow the editing session to end
    optional func textFieldDidEndEditing(textField: UITextField) // may be called if forced even if shouldEndEditing returns NO (e.g. view removed from window) or endEditing:YES called

    optional func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool // return NO to not change text

    optional func textFieldShouldClear(textField: UITextField) -> Bool // called when clear button pressed. return NO to ignore (no notifications)
    optional func textFieldShouldReturn(textField: UITextField) -> Bool // called when 'return' key pressed. return NO to ignore.
}

来自swift docs:

struct UIControlEvents : RawOptionSetType {
    init(_ rawValue: UInt)
    init(rawValue: UInt)

    static var TouchDown: UIControlEvents { get } // on all touch downs
    static var TouchDownRepeat: UIControlEvents { get } // on multiple touchdowns (tap count > 1)
    static var TouchDragInside: UIControlEvents { get }
    static var TouchDragOutside: UIControlEvents { get }
    static var TouchDragEnter: UIControlEvents { get }
    static var TouchDragExit: UIControlEvents { get }
    static var TouchUpInside: UIControlEvents { get }
    static var TouchUpOutside: UIControlEvents { get }
    static var TouchCancel: UIControlEvents { get }

    static var ValueChanged: UIControlEvents { get } // sliders, etc.

    static var EditingDidBegin: UIControlEvents { get } // UITextField
    static var EditingChanged: UIControlEvents { get }
    static var EditingDidEnd: UIControlEvents { get }
    static var EditingDidEndOnExit: UIControlEvents { get } // 'return key' ending editing

    static var AllTouchEvents: UIControlEvents { get } // for touch events
    static var AllEditingEvents: UIControlEvents { get } // for UITextField
    static var ApplicationReserved: UIControlEvents { get } // range available for application use
    static var SystemReserved: UIControlEvents { get } // range reserved for internal framework use
    static var AllEvents: UIControlEvents { get }
}

UITextField没有响应"touchUpInside"看到右侧,你会发现它是可接受的控件事件

Answer 4

更新Swift 3

这是Swift 3的代码:

myTextField.addTarget(self, action: #selector(myTargetFunction), for: .touchDown)

这是功能:

func myTargetFunction() {
    print("It works!")
}

Answer 5

我提到了Apple的UIControlEvents文档并提出了以下内容:

首先将UITextFieldDelegate添加到您的类,然后,

textBox.delegate = self
textBox.addTarget(self, action: #selector(TextBoxOn(_:)),for: .editingDidBegin)
textBox.addTarget(self, action: #selector(TextBoxOff(_:)),for: .editingDidEnd)

具有以下功能:

func TextBoxOff(_ textField: UITextField) {
     code
         }                
}

func TextBox(_ textField: UITextField) {
    code
         }
}

Answer 6

对于Swift 3.1:

1)创建手势识别器:

let textViewRecognizer = UITapGestureRecognizer()

2)向识别器添加处理程序:

textViewRecognizer.addTarget(self, action: #selector(tappedTextView(_:))) 

3)将识别器添加到文本视图中:

textView.addGestureRecognizer(textViewRecognizer)

4)将处理程序添加到您的类:

func tappedTextView(_ sender: UITapGestureRecognizer) {
        print("detected tap!")
}

Answer 7

为了使这更清楚一些，这些东西需要到位。我用它来做到这一点，所以如果用户在我自己的信用应用程序中输入了一些textField东西，借方中的任何内容都会textField被删除。

1. UITextFieldDelegate需要在视图控制器中声明，即类 SecondViewController：
2. 检测器函数 func myDebitDetector func myCreditDetector需要在 ViewController 类中。

3. 将debit.addTarget 和 credit.addtarget放入视图中。

4. @IBOutlet 弱变量借记：UITextField！ 和 @IBOutlet 弱变量信用：UITextField！是故事板上的文本字段并连接到视图控制器。

   class SecondViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource, UITextFieldDelegate {
   
   @IBOutlet weak var credit: UITextField!
   @IBOutlet weak var debit: UITextField!
   
       func myDebitDetector(textfield: UITextField ){
           print("using debit")
           credit.text = ""
   
       }
   
       func myCreditDetector(textfield: UITextField) {
           print("using cedit")
           debit.text = ""
       }
   
       override func viewWillAppear(animated: Bool) {
   
   
   
           debit.addTarget(self, action: "myDebitDetector:", forControlEvents: UIControlEvents.TouchDown)
           credit.addTarget(self, action: "myCreditDetector:", forControlEvents: UIControlEvents.TouchDown)
       ....
   
       }
   }