如何检查多个文本字段是否为 nil，并相应地在 Swift 中启用按钮

huangapple
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英文:

How to check multiple textfields are nil or not and enable button accordingly in swift

问题

需要在所有文本字段都有文本时才能启用 nextBtn。

尝试以下代码：但是使用此代码，当我点击第一个文本字段时，nextBtn 就会启用，为什么呢？如何只在填写完所有文本字段后才启用 nextBtn？请指导我。

  1. override func viewDidLoad() {
  2.     super.viewDidLoad()
  3.     
  4.     nextBtn.isEnabled = false
  5.     nextBtn.alpha = 0.5
  6. }
  8. func textFieldDidBeginEditing(_ textField: UITextField) {
  9.     
  10.     if fullNameTextField.text == nil{
  11.         nextBtn.alpha = 0.5
  12.         nextBtn.isEnabled = false
  13.     }
  14.     else if dateOfBirthTextField.text == nil{
  15.         nextBtn.alpha = 0.5
  16.         nextBtn.isEnabled = false
  17.     }
  18.     else if schoolNameTextField.text == nil{
  19.         nextBtn.alpha = 0.5
  20.         nextBtn.isEnabled = false
  21.     }
  22.     else if schoolLocationTextField.text == nil{
  23.         nextBtn.alpha = 0.5
  24.         nextBtn.isEnabled = false
  25.     }
  26.     else if gradeClassTextField.text == nil{
  27.         nextBtn.alpha = 0.5
  28.         nextBtn.isEnabled = false
  29.     }
  30.     else{
  31.         nextBtn.alpha = 1
  32.         nextBtn.isEnabled = true
  33.     }
  34. }

编辑：我尝试了这样做。现在，在第二个文本字段上点击后，nextBtn 变为可用，为什么呢？请指导我。

  1. func textFieldDidBeginEditing(_ textField: UITextField) {
  3.     if fullNameTextField.text == "", dateOfBirthTextField.text == "", schoolNameTextField.text == "", gradeClassTextField.text == ""{
  4.         nextBtn.alpha = 0.5
  5.         nextBtn.isEnabled = false
  6.     }
  7.     else{
  8.         nextBtn.alpha = 1
  9.         nextBtn.isEnabled = true
  10.     }
  11. }
英文:

I need to enable nextBtn when all textfields has some text only

tried below code: but with this code when i tap on first textfield then my nextBtn becomes enabled why? how to make nextBtn enable after filling the all textfields only. please guide me

  1. override func viewDidLoad() {
  2.     super.viewDidLoad()
  3.     
  4.     nextBtn.isEnabled = false
  5.     nextBtn.alpha = 0.5
  6. }
  8. func textFieldDidBeginEditing(_ textField: UITextField) {
  9.     
  10.     if fullNameTextField.text == nil{
  11.         nextBtn.alpha = 0.5
  12.         nextBtn.isEnabled = false
  13.     }
  14.     else if dateOfBirthTextField.text == nil{
  15.         nextBtn.alpha = 0.5
  16.         nextBtn.isEnabled = false
  17.     }
  18.     else if schoolNameTextField.text == nil{
  19.         nextBtn.alpha = 0.5
  20.         nextBtn.isEnabled = false
  21.     }
  22.     else if schoolLocationTextField.text == nil{
  23.         nextBtn.alpha = 0.5
  24.         nextBtn.isEnabled = false
  25.     }
  26.     else if gradeClassTextField.text == nil{
  27.         nextBtn.alpha = 0.5
  28.         nextBtn.isEnabled = false
  29.     }
  30.     else{
  31.         nextBtn.alpha = 1
  32.         nextBtn.isEnabled = true
  33.     }
  34. }

edit: i have tried like this. now after taping on second textfield then nextBtn becomes enable why? please guide me

  1. func textFieldDidBeginEditing(_ textField: UITextField) {
  3.     if fullNameTextField.text == "", dateOfBirthTextField.text == "", schoolNameTextField.text == "", gradeClassTextField.text == ""{
  4.         nextBtn.alpha = 0.5
  5.         nextBtn.isEnabled = false
  6.     }
  7.     else{
  8.         nextBtn.alpha = 1
  9.         nextBtn.isEnabled = true
  10.     }
  11. }

答案1

得分: 1

你可以通过以下方式简单地完成它：

  1. let fields = [fullNameTextField, dateOfBirthTextField, schoolNameTextField, schoolLocationTextField, gradeClassTextField]
  2. let isValidFields = fields.allSatisfy { field in
  3.     !field.text.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty
  4. }
  5. if isValidFields {
  6.     nextBtn.alpha = 1
  7.     nextBtn.isEnabled = true
  8. } else {
  9.     nextBtn.alpha = 0.5
  10.     nextBtn.isEnabled = false
  11. }
英文:

You can simply do it by doing it like this

  1. let fields = [fullNameTextField, dateOfBirthTextField, schoolNameTextField, schoolLocationTextField, gradeClassTextField]
  2. let isVaildFields = fields.allSatisfy { field in
  3.             !field.text.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty
  4.          } 
  5. if isVaildFields {
  6.     nextBtn.alpha = 1
  7.     nextBtn.isEnabled = true
  8. } else {
  9.     nextBtn.alpha = 0.5
  10.     nextBtn.isEnabled = false
  11. }

答案2

得分: 0

以下是翻译好的代码部分：

  1. 一种方法是这样的
  3.     class ViewController: UIViewController, UITextFieldDelegate {
  4.         
  5.         @IBOutlet weak var fullNameTextField: UITextField!
  6.         @IBOutlet weak var dateOfBirthTextField: UITextField!
  7.         @IBOutlet weak var schoolNameTextField: UITextField!
  8.         @IBOutlet weak var schoolLocationTextField: UITextField!
  9.         @IBOutlet weak var gradeClassTextField: UITextField!
  10.         @IBOutlet weak var nextBtn: UIButton!
  11.         
  12.         override func viewDidLoad() {
  13.             super.viewDidLoad()
  14.             
  15.             nextBtn.isEnabled = false
  16.             nextBtn.alpha = 0.5
  17.         }
  18.     
  19.         func textFieldDidBeginEditing(_ textField: UITextField) {
  20.             let fields = [fullNameTextField, dateOfBirthTextField, schoolNameTextField,
  21.                           schoolLocationTextField, gradeClassTextField]
  22.             let isValidFields = fields.allSatisfy {
  23.                 !($0?.text?.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty ?? true)
  24.             }
  25.             
  26.             if isValidFields {
  27.                 nextBtn.alpha = 1
  28.                 nextBtn.isEnabled = true
  29.             } else {
  30.                 nextBtn.alpha = 0.5
  31.                 nextBtn.isEnabled = false
  32.             }
  33.         }
  34.     }
  36. 你也可以通过创建文本字段 `@IBOutlet` 的列表来实现，如下所示：
  38.     class ViewController: UIViewController, UITextFieldDelegate {
  39.         
  40.         @IBOutlet var textFields: [UITextField]!
  41.         @IBOutlet weak var nextBtn: UIButton!
  42.         
  43.         override func viewDidLoad() {
  44.             super.viewDidLoad()
  45.             
  46.             nextBtn.isEnabled = false
  47.             nextBtn.alpha = 0.5
  48.         }
  49.     
  50.         func textFieldDidBeginEditing(_ textField: UITextField) {
  51.             let isValidFields = textFields.allSatisfy {
  52.                 !($0.text?.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty ?? true)
  53.             }
  54.             
  55.             if isValidFields {
  56.                 nextBtn.alpha = 1
  57.                 nextBtn.isEnabled = true
  58.             } else {
  59.                 nextBtn.alpha = 0.5
  60.                 nextBtn.isEnabled = false
  61.             }
  62.         }
  63.     }
  65. 如果你只想对单独的文本字段进行操作，可以简单地这样做。
  67.     class ViewController: UIViewController, UITextFieldDelegate {
  68.         
  69.         @IBOutlet weak var fullNameTextField: UITextField!
  70.         @IBOutlet weak var dateOfBirthTextField: UITextField!
  71.         @IBOutlet weak var schoolNameTextField: UITextField!
  72.         @IBOutlet weak var schoolLocationTextField: UITextField!
  73.         @IBOutlet weak var gradeClassTextField: UITextField!
  74.         @IBOutlet weak var nextBtn: UIButton!
  75.         
  76.         override func viewDidLoad() {
  77.             super.viewDidLoad()
  78.             
  79.             nextBtn.isEnabled = false
  80.             nextBtn.alpha = 0.5
  81.         }
  82.         
  83.         func isValid(_ textField: UITextField) -> Bool {
  84.             return !(textField.text?.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty ?? true)
  85.         }
  86.     
  87.         func textFieldDidBeginEditing(_ textField: UITextField) {
  88.             if isValid(fullNameTextField), isValid(dateOfBirthTextField),
  89.                isValid(schoolNameTextField), isValid(schoolLocationTextField),
  90.                isValid(gradeClassTextField) {
  91.                 nextBtn.alpha = 1
  92.                 nextBtn.isEnabled = true
  93.             } else {
  94.                 nextBtn.alpha = 0.5
  95.                 nextBtn.isEnabled = false
  96.             }
  97.         }
  98.     }
英文:

One way of doing it is like

  1. class ViewController: UIViewController, UITextFieldDelegate {
  2. @IBOutlet weak var fullNameTextField: UITextField!
  3. @IBOutlet weak var dateOfBirthTextField: UITextField!
  4. @IBOutlet weak var schoolNameTextField: UITextField!
  5. @IBOutlet weak var schoolLocationTextField: UITextField!
  6. @IBOutlet weak var gradeClassTextField: UITextField!
  7. @IBOutlet weak var nextBtn: UIButton!
  8. override func viewDidLoad() {
  9. super.viewDidLoad()
  10. nextBtn.isEnabled = false
  11. nextBtn.alpha = 0.5
  12. }
  13. func textFieldDidBeginEditing(_ textField: UITextField) {
  14. let fields = [fullNameTextField, dateOfBirthTextField, schoolNameTextField,
  15. schoolLocationTextField, gradeClassTextField]
  16. let isValidFields = fields.allSatisfy {
  17. !($0?.text?.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty ?? true)
  18. }
  19. if isValidFields {
  20. nextBtn.alpha = 1
  21. nextBtn.isEnabled = true
  22. } else {
  23. nextBtn.alpha = 0.5
  24. nextBtn.isEnabled = false
  25. }
  26. }
  27. }

You can also do it by creating list of text field @IBOutlet, Like following:

  1. class ViewController: UIViewController, UITextFieldDelegate {
  2. @IBOutlet var textFields: [UITextField]!
  3. @IBOutlet weak var nextBtn: UIButton!
  4. override func viewDidLoad() {
  5. super.viewDidLoad()
  6. nextBtn.isEnabled = false
  7. nextBtn.alpha = 0.5
  8. }
  9. func textFieldDidBeginEditing(_ textField: UITextField) {
  10. let isValidFields = textFields.allSatisfy {
  11. !($0.text?.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty ?? true)
  12. }
  13. if isValidFields {
  14. nextBtn.alpha = 1
  15. nextBtn.isEnabled = true
  16. } else {
  17. nextBtn.alpha = 0.5
  18. nextBtn.isEnabled = false
  19. }
  20. }
  21. }

And if you only want to do it for individual textfields, you can simply do like this.

  1. class ViewController: UIViewController, UITextFieldDelegate {
  2. @IBOutlet weak var fullNameTextField: UITextField!
  3. @IBOutlet weak var dateOfBirthTextField: UITextField!
  4. @IBOutlet weak var schoolNameTextField: UITextField!
  5. @IBOutlet weak var schoolLocationTextField: UITextField!
  6. @IBOutlet weak var gradeClassTextField: UITextField!
  7. @IBOutlet weak var nextBtn: UIButton!
  8. override func viewDidLoad() {
  9. super.viewDidLoad()
  10. nextBtn.isEnabled = false
  11. nextBtn.alpha = 0.5
  12. }
  13. func isValid(_ textField: UITextField) -> Bool {
  14. return !(textField.text?.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty ?? true)
  15. }
  16. func textFieldDidBeginEditing(_ textField: UITextField) {
  17. if isValid(fullNameTextField), isValid(dateOfBirthTextField),
  18. isValid(schoolNameTextField), isValid(schoolLocationTextField),
  19. isValid(gradeClassTextField) {
  20. nextBtn.alpha = 1
  21. nextBtn.isEnabled = true
  22. } else {
  23. nextBtn.alpha = 0.5
  24. nextBtn.isEnabled = false
  25. }
  26. }
  27. }

huangapple
  • 本文由 发表于 2023年6月15日 19:24:38
  • 转载请务必保留本文链接：https://go.coder-hub.com/76481969.html
  • swift
  • uibutton
  • uitextfield
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