如何在UIAlertController中验证TextField? [英] How do I validate TextFields in an UIAlertController?
本文介绍了如何在UIAlertController中验证TextField?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
有谁能告诉我如何在 UIAlertController
中验证 UITextFields
?
Can anyone tell me how to validate UITextFields
inside of a UIAlertController
?
我需要它来阻止用户单击保存,除非输入两个字段。
I need it to prevent the user from clicking "Save" unless both fields are entered.
这是我到目前为止的代码:
Here is my code so far:
@IBAction func btnStart(sender: AnyObject) {
var alert = UIAlertController(title: "New user",
message: "Add a new user",
preferredStyle: .Alert)
let saveAction = UIAlertAction(title: "Save",
style: .Default) { (action: UIAlertAction!) -> Void in
self.textFieldName = alert.textFields![0] as UITextField
self.textFieldEmail = alert.textFields![1] as UITextField
self.saveUser(self.textFieldName.text, email: self.textFieldEmail.text)
self.tableView.reloadData()
}
saveAction.enabled = false
let cancelAction = UIAlertAction(title: "Cancel",
style: .Default) { (action: UIAlertAction!) -> Void in
}
alert.addTextFieldWithConfigurationHandler {
(textFieldName: UITextField!) in
textFieldName.placeholder = "Enter full name"
}
alert.addTextFieldWithConfigurationHandler {
(textFieldEmail: UITextField!) in
textFieldEmail.placeholder = "Enter valid email adress"
textFieldEmail.keyboardType = .EmailAddress
}
alert.addAction(saveAction)
alert.addAction(cancelAction)
presentViewController(alert,
animated: true,
completion: nil)
}
这是我验证电子邮件字段的功能:
This is my function for validating the Email field:
func isValidEmail(testStr:String) -> Bool {
let emailRegEx = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}"
if let emailTest = NSPredicate(format:"SELF MATCHES %@", emailRegEx) {
return emailTest.evaluateWithObject(testStr)
}
return false
}
推荐答案
最优雅方法是使用
NotificationCenter.default.addObserver(forName: NSNotification.Name.UITextFieldTextDidChange...
Swift 3.0示例
Swift 3.0 example
let alert = UIAlertController(title: nil, message: nil, preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
let saveAction = UIAlertAction(title:"Save", style: .destructive, handler: { (action) -> Void in
})
alert.addAction(saveAction)
alert.addTextField(configurationHandler: { (textField) in
textField.placeholder = "Enter something"
NotificationCenter.default.addObserver(forName: NSNotification.Name.UITextFieldTextDidChange, object: textField, queue: OperationQueue.main) { (notification) in
saveAction.isEnabled = textField.text!.length > 0
}
})
present(alert, animated: true, completion: nil)
这篇关于如何在UIAlertController中验证TextField?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
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