问题
so i make this otp screen but i have some catch,
i make this otp screen with bunch of uitextfield and i make the logic of it, but i just cant delete on of the num in the textfield that i make
the textfield wont delete when i fill like the first 2 of my num, even i pressess backButton it wont work.....but it will work when i fill the whole num of textfield, in my case is six.
so i have to fill all six of the number and i can delete the number from the textfield, it wont work if only half fill in the textfield.
heres my code :
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
if ((textField.text?.count)! < 1) && (string.count > 0) {
if textField == txtOTP1 {
txtOTP2.becomeFirstResponder()
}
if textField == txtOTP2 {
txtOTP3.becomeFirstResponder()
}
if textField == txtOTP3 {
txtOTP4.becomeFirstResponder()
}
if textField == txtOTP4 {
txtOTP5.becomeFirstResponder()
}
if textField == txtOTP5{
txtOTP6.becomeFirstResponder()
}
if textField == txtOTP6{
txtOTP6.resignFirstResponder()
}
textField.text = string
return false
}else if ((textField.text?.count)! >= 1) && (string.count == 0) {
if textField == txtOTP2{
txtOTP1.becomeFirstResponder()
}
if textField == txtOTP3{
txtOTP2.becomeFirstResponder()
}
if textField == txtOTP4{
txtOTP3.becomeFirstResponder()
}
if textField == txtOTP5{
txtOTP4.becomeFirstResponder()
}
if textField == txtOTP6{
txtOTP5.becomeFirstResponder()
}
if textField == txtOTP1{
txtOTP1.resignFirstResponder()
}
textField.text = ""
return false
}
else if (textField.text?.count)! >= 1 {
textField.text = string
return false
}
return true
}
thats the code i use to make the otp uitextField logic......please tell me i know theres something wrong with my logic, thanks.
- i watch a tutorial to make this otp screen in this vid https://www.youtube.com/watch?v=gZnBXh0TRO8
and according to the maker, he said that to fix this issue i just need to "set user interactions for textfield false and make first textfield first responder", i think i just did that but i maybe i did it wrong....
i really need to fix this guys, thanks.
回答1:
Instead of fixing that code I prefer to create a custom text field that would inform when the deleteBackward key is pressed. So first subclass a UITextField:
import UIKit
class SingleDigitField: UITextField {
// create a boolean property to hold the deleteBackward info
var pressedDelete = false
// customize the text field as you wish
override func willMove(toSuperview newSuperview: UIView?) {
keyboardType = .numberPad
textAlignment = .center
backgroundColor = .blue
isSecureTextEntry = true
isUserInteractionEnabled = false
}
// hide cursor
override func caretRect(for position: UITextPosition) -> CGRect { .zero }
// hide selection
override func selectionRects(for range: UITextRange) -> [UITextSelectionRect] { [] }
// disable copy paste
override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool { false }
// override deleteBackward method, set the property value to true and send an action for editingChanged
override func deleteBackward() {
pressedDelete = true
sendActions(for: .editingChanged)
}
}
Now in your ViewCOntroller:
import UIKit
class ViewController: UIViewController {
// connect the textfields outlets
@IBOutlet weak var firstDigitField: SingleDigitField!
@IBOutlet weak var secondDigitField: SingleDigitField!
@IBOutlet weak var thirdDigitField: SingleDigitField!
@IBOutlet weak var fourthDigitField: SingleDigitField!
override func viewDidLoad() {
super.viewDidLoad()
// add a target for editing changed for each field
[firstDigitField,secondDigitField,thirdDigitField,fourthDigitField].forEach {
$0?.addTarget(self, action: #selector(editingChanged), for: .editingChanged)
}
// make the firsDigitField the first responder
firstDigitField.isUserInteractionEnabled = true
firstDigitField.becomeFirstResponder()
}
// here you control what happens to each change that occurs to the fields
@objc func editingChanged(_ textField: SingleDigitField) {
// check if the deleteBackwards key was pressed
if textField.pressedDelete {
// reset its state
textField.pressedDelete = false
// if the field has text empty its content
if textField.hasText {
textField.text = ""
} else {
// otherwise switch the field, resign the first responder and activate the previous field and empty its contents
switch textField {
case secondDigitField, thirdDigitField, fourthDigitField:
textField.resignFirstResponder()
textField.isUserInteractionEnabled = false
switch textField {
case secondDigitField:
firstDigitField.isUserInteractionEnabled = true
firstDigitField.becomeFirstResponder()
firstDigitField.text = ""
case thirdDigitField:
secondDigitField.isUserInteractionEnabled = true
secondDigitField.becomeFirstResponder()
secondDigitField.text = ""
case fourthDigitField:
thirdDigitField.isUserInteractionEnabled = true
thirdDigitField.becomeFirstResponder()
thirdDigitField.text = ""
default:
break
}
default: break
}
}
}
// make sure there is only one character and it is a number otherwise delete its contents
guard textField.text?.count == 1, textField.text?.last?.isWholeNumber == true else {
textField.text = ""
return
}
// switch the textField, resign the first responder and make the next field active
switch textField {
case firstDigitField, secondDigitField, thirdDigitField:
textField.resignFirstResponder()
textField.isUserInteractionEnabled = false
switch textField {
case firstDigitField:
secondDigitField.isUserInteractionEnabled = true
secondDigitField.becomeFirstResponder()
case secondDigitField:
thirdDigitField.isUserInteractionEnabled = true
thirdDigitField.becomeFirstResponder()
case thirdDigitField:
fourthDigitField.isUserInteractionEnabled = true
fourthDigitField.becomeFirstResponder()
default: break
}
case fourthDigitField:
fourthDigitField.resignFirstResponder()
default: break
}
}
}
Xcode 12 sample project
来源:https://stackoverflow.com/questions/63002801/how-to-create-otp-verification-screen-and-detect-delete-backward-on-multiple-uit