iOS/Swift：如何檢測 UITextField 上的觸摸動作

Question

我想檢測 UITextField 上的觸摸動作。

觸摸文本字段內部似乎不會觸發“Touch Up Inside”動作。

Answer 1

似乎沒有為UITextField啟用“Touch Up Inside”，但“Touch Down”有效。

所以解決方法如下：

斯威夫特 4.x

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

斯威夫特 3.x

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

@objc func myTargetFunction(textField: UITextField) {
    print("myTargetFunction")
}

Answer 2

Swift 4 及更高版本：

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

這是一個委托函數。

Answer 3

這是 Swfit：

並且您不需要使用“touchUpInside”，只需使用如下委托方法：

使您的視圖控制器成為委托：

class ViewController: UIViewController, UITextFieldDelegate{

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

這是其他委托方法：

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.
}

來自快速文檔：

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 不響應 "touchUpInside" 看右邊，你會發現它是可接受的控制事件

Answer 4

Swift 3 更新

這是 Swift 3 的代碼：

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

這是函數：

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

Answer 5

我參考了Apple的UIControlEvents 文檔並提出了以下內容：

首先將 UITextFieldDelegate 添加到您的類中，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

對於 Swift 3.1：

1）創建一個手勢識別器：

let textViewRecognizer = UITapGestureRecognizer()

2) 向識別器添加處理程序：

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

3) 將識別器添加到文本視圖中：

textView.addGestureRecognizer(textViewRecognizer)

4) 將處理程序添加到您的類中：

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

Answer 7

為了使這更清楚一些，這些東西需要到位。 我用它來做到這一點，如果用戶在我自己的信用textField的應用程序中輸入了一些東西，借方textField textField任何內容都會被刪除。

1. UITextFieldDelegate需要在視圖控制器中聲明，即類 SecondViewController：
2. 檢測器函數func myDebitDetector func myCreditDetector需要在 ViewController 類中。

3. 將debit.addTarget 和 credit.addtarget放入視圖中。

4. @IBOutlet 弱變量借記：UITextField！ 和@IBOutlet 弱變量信用：UITextField！ 是故事板上的文本字段並連接到視圖控制器。

    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) .... } }

Answer 8

將 UITextField 委托設置為您的視圖控制器

對象-C

textField.delegate = self;

迅速

textField.delegate = self

實現委托方法

對象-c

-(void)textField:(UITextField*)textField didBeginEditing {
   // User touched textField
}

迅速

func textFieldDidBeginEditing(textField: UITextField!) {    //delegate method

}

Answer 9

斯威夫特 3.0 版本：

textFieldClientName.addTarget(self, action: Selector(("myTargetFunction:")), for: UIControlEvents.touchDown)

Answer 10

斯威夫特 4.2。

嘗試.editingDidEnd而不是.touchDown和delegate 。

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

@objc func myTargetFunction(textField: UITextField) {
    print("textfield pressed")
}

Answer 11

在 xamarin.iOS 上我很容易使用：

YourTextField.WeakDelegate = this;

[...]

[Export("textFieldDidBeginEditing:")]
public void TextViewChanged(UITextField textField)
{
    if (YourTextField.Equals(textField))
        IsYourTextFileFocused = true;
}

Answer 12

** Swift 4.0 + **
Use custom action like this


YourTextField.addTarget(self, action: #selector(myTargetFunction(_:)), for: .allEditingEvents)

@IBAction private func myTargetFunction(_ sender: Any) {
        if let textField = sender as? UITextField {
            // get textField here
        }
    }