如何在同一视图控制器上选择文本字段（Swift 3）

Question

I have 2 textfields. I would like what ever is entered in textfield a to be displayed in textfield b. However textfield b is used just for display. The user can only enter a name in textfield a. The user enters a name in textfield a and it will be displayed in textfield b.

    import UIKit

class ViewController: UIViewController {

@IBOutlet var a: UITextField!
@IBOutlet var b: UITextField!
override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.

    b.isEnabled = false



}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}}

enter image description here

Answer 1

You can use textfield's delegate methods like "textfieldEndEditing" or "textfieldShouldChangeCharacterinrange" and in this delegate method you can set text of your textfield b. Second thing if you just want to display text then you can use uilable also instead of textfield b!

Answer 2

import UIKit

class ViewController: UIViewController {
@IBOutlet weak var a: UITextField!
@IBOutlet weak var b: UITextField!

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
    b.isEnabled = false
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}


}

// use extensions your code will be clear always 
// UITextfield delegate
extension ViewController: UITextFieldDelegate {
func textFieldDidEndEditing(_ textField: UITextField) {
    // if you have many textfields and the user dismissed the keyboard or tapped any other textfield
    if textField === a {
        b.text = textField.text
    }
}

// if the user clicked the return key in keyboard
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
    // this works if you have only a and b textfields
    // b.text = textField.text

    // use this if statment if you have many text fields
    if textField === a {
        b.text = textField.text
    }
    return true
}

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
    // if you want to see your text changes live as soon as the user clicks any button
    b.text = textField.text

    return true
  }

}

Don't forget to connect TextFields to delegate from storyboard or nib whatever your using