[英]Disable / Enable a button in Xcode
嗨,我是Swift编程的新手。 我正在尝试做的是在viewDidLoad中禁用我的按钮(登录),仅在文本字段中包含文本时才启用。 这是我到目前为止所取得的成就。 (虽然不多!)
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
signIn.isEnabled = false
// Do any additional setup after loading the view, typically from a nib.
}
@IBOutlet weak var emailtxt: UITextField!
@IBOutlet weak var passwordtxt: UITextField!
@IBOutlet weak var signIn: UIButton!
我需要帮助在signIn中创建一个函数,该函数将禁用按钮,直到文本字段(emailtxt和passwordtxt)中包含文本,然后继续。
很高兴有人可以对我进行分类。 提前致谢!
像这样将ViewController
设置为emailtxt
和passwordtxt
委托,
override func viewDidLoad() {
super.viewDidLoad()
signIn.isEnabled = false
emailtxt.delegate = self
passwordtxt.delegate = self
// Do any additional setup after loading the view, typically from a nib.
}
使您的ViewController
符合UITextFieldDelegate
并在文本输入完成后启用/禁用,
extension ViewController: UITextFieldDelegate {
func textFieldDidEndEditing(_ textField: UITextField) {
if emailtxt.text?.isEmpty == false && passwordtxt.text?.isEmpty == false {
signIn.isEnabled = true
} else {
signIn.isEnabled = false
}
}
}
这是您共享的代码的修补程序。
import UIKit
extension UIViewController {
func hideKeyboardWhenTappedAround() {
let tap: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(UIViewController.dismissKeyboard))
tap.cancelsTouchesInView = false
view.addGestureRecognizer(tap)
}
@objc func dismissKeyboard() {
view.endEditing(true)
}
}
extension SignInVC: UITextFieldDelegate {
func textFieldDidEndEditing(_ textField: UITextField) {
if emailtxt.text?.isEmpty == false && passwordtxt.text?.isEmpty == false {
signIn.isEnabled = true
} else {
signIn.isEnabled = false
}
}
}
class SignInVC: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
signIn.isEnabled = false
emailtxt.delegate = self
passwordtxt.delegate = self
self.hideKeyboardWhenTappedAround()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
@IBOutlet weak var emailtxt: UITextField!
@IBOutlet weak var passwordtxt: UITextField!
@IBOutlet weak var signIn: UIButton!
}
首先在viewDidLoad()
为所有textField添加这些:
emailtxt.addTarget(self, action: #selector(textFieldDidChange(_:)),
for: UIControlEvents.editingChanged)
passwordtxt.addTarget(self, action: #selector(textFieldDidChange(_:)),
for: UIControlEvents.editingChanged)
然后使用:
@objc func textFieldDidChange(_ textField: UITextField) {
self.buttonIsEnabled()
}
func buttonIsEnabled() {
var buttonIsEnabled = true
defer {
self.signIn.isEnabled = buttonIsEnabled
}
guard let emailtxt = self.emailtxt.text, !emailtxt.isEmpty else {
addButtonIsEnabled = false
return
}
guard let passwordtxt = self. passwordtxt.text, ! passwordtxt.isEmpty else {
addButtonIsEnabled = false
return
}
}
我在代码中使用了这种方式,效果很好。
甚至您可以为buttonIsEnabled添加更多方法以进行其他检查,例如:
self.checkEmailIsValid(for: emailtxt)
当然,您应该在处理以下方法之前:
func checkEmailIsValid(for: String) {
//...
}
我要做的是从您的一个文本字段中创建一个IBAction,并将事件设置为Editing Changed
:
该代码应如下所示:
@IBAction func textFieldEditingDidChange(_ sender: UITextField) {
}
然后,您可以通过将同一插座从插座拖到其余字段来将其连接到两个文本字段。 如果两个连接均正确,则单击IBAction左侧的圆圈应显示两个文本字段:
现在,每次您在两个字段中的任何文本更改时, 都会触发该操作。
然后,在文件的顶部,我将创建一个返回false的计算属性,除非两个字段中都包含以下内容:
var shouldEnableButton: Bool {
guard let text1 = textField1.text, let text2 = textField2.text else {
return false
}
return text1.isEmpty && text2.isEmpty ? false : true
}
最后,我们将shouldEnableButton
添加到我们的IBAction中:
@IBAction func textFieldEditingDidChange(_ sender: UITextField) {
button.isEnabled = shouldEnableButton
}
当您将第二个文本字段连接到插座时,它将错误地将 Editing Did End
作为其事件 分配 :
删除此事件,然后单击并从“ Editing Changed
拖动到您的IBAction中:
使用SwiftValidator
https://github.com/SwiftValidatorCommunity/SwiftValidator
这样,您将如下设置电子邮件和密码的验证
import SwiftValidator
let validator = Validator()
validator.registerField(emailTextField, errorLabel: emailErrorLabel, rules: [RequiredRule(), EmailRule(message: "Invalid email")])
// MARK: - ValidationDelegate
extension ViewController: ValidationDelegate {
func validationSuccessful() {
self.loginUser()
}
func validationFailed(_ errors:[(Validatable ,ValidationError)]) {
for (field, error) in errors {
//Handle as per need - show extra label - shake view etc
/*
if let field = field as? UITextField {
Utilities.shakeTheView(shakeView: field)
}
error.errorLabel?.text = error.errorMessage
error.errorLabel?.isHidden = false
*/
}
}
}
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