键盘上按“Enter”键时如何触发功能

Question

当用户按下手机键盘上的“Enter”时，如何触发测试功能的按键回调功能？

import UIKit
class ViewController: UIViewController, UITextFieldDelegate {
    @IBOutlet weak var label: UILabel!
    @IBOutlet weak var textfield: UITextField!

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

    @IBAction func btn(_ sender: Any) {
        //textfield.resignFirstResponder()
        label.text = textfield.text!
        print("\n func completed \n")
    }

    func test(textField: UITextField!) {
        textfield.resignFirstResponder()
        print("\n func completed \n")
    }
}

Answer 1

你可以直接试试

func textFieldShouldReturn(_ textField: UITextField) -> Bool {    
   textField.resignFirstResponder() // options 1
   self.test(textField)  // option 2
   self.calledFromAnyWhere() // option 3  
   return true
}

编辑：如果要调用按钮的操作，则首选创建共享功能

 @IBAction func btn(_ sender: Any) {

   self.calledFromAnyWhere()
}

func calledFromAnyWhere()
{
    // any content
}

Answer 2

您可以添加目标来处理特定事件，如下所示：

textField.addTarget(self, action: #selector(editingDidEnd), for: .editingDidEndOnExit)


@objc func editingDidEnd() {
    // Do whatever you would like here, in your case
    self.btnCallback()
}