有没有一种方法可以使用 swift 在 alertview 内的文本字段中提供验证
Posted
技术标签:
【中文标题】有没有一种方法可以使用 swift 在 alertview 内的文本字段中提供验证【英文标题】：Is there a way of providing validation in the textfield which is inside alertview using swift 【发布时间】：2016-09-26 07:05:14 【问题描述】：我有一个警报视图，它显示一个用户必须输入的文本字段。问题是如果用户单击“授权”而不输入它，则警报视图将被解雇。我想不出一种在不关闭警报视图的情况下向用户显示它是强制性的方法。
代码：
func tableView(tableView: UITableView!, didSelectRowAtIndexPath indexPath: NSIndexPath!)
print("You selected cell #\(self.empNameArr[indexPath.row])!")
let alertController = UIAlertController(title: "OD Authorise", message: "", preferredStyle: UIAlertControllerStyle.Alert)
let AUTHORISE = UIAlertAction(title: "AUTHORISE", style: UIAlertActionStyle.Default, handler:
alert -> Void in
let firstTextField = alertController.textFields![3] as UITextField
print("<><><><><><>",firstTextField.text)
)
let DENY = UIAlertAction(title: "DENY", style: UIAlertActionStyle.Default, handler:
(action : UIAlertAction!) -> Void in
)
let CANCEL = UIAlertAction(title: "CANCEL", style: UIAlertActionStyle.Default, handler:
(action : UIAlertAction!) -> Void in
)
alertController.addTextFieldWithConfigurationHandler (txtRemarks : UITextField!) -> Void in
txtRemarks.font = UIFont(name: (txtRemarks.font?.fontName)!, size: 11)
txtRemarks.text = " Employee Name :\(self.empNameArr[indexPath.row]) "
txtRemarks.userInteractionEnabled=false
txtRemarks.borderStyle = UITextBorderStyle.None
alertController.addTextFieldWithConfigurationHandler (txtRemarks : UITextField!) -> Void in
txtRemarks.font = UIFont(name: (txtRemarks.font?.fontName)!, size: 11)
txtRemarks.text = " From Date :\(self.leavDateArr[indexPath.row]) "
txtRemarks.userInteractionEnabled=false
txtRemarks.borderStyle = UITextBorderStyle.None
alertController.addTextFieldWithConfigurationHandler (txtRemarks : UITextField!) -> Void in
txtRemarks.font = UIFont(name: (txtRemarks.font?.fontName)!, size: 11)
txtRemarks.text = " To Date :\(self.ToDate[indexPath.row]) "
txtRemarks.userInteractionEnabled=false
txtRemarks.borderStyle = UITextBorderStyle.None
alertController.addTextFieldWithConfigurationHandler (txtRemarks : UITextField!) -> Void in
txtRemarks.font = UIFont(name: (txtRemarks.font?.fontName)!, size: 11)
txtRemarks.text = " Leave reason :\(self.Reason[indexPath.row]) "
txtRemarks.userInteractionEnabled=false
txtRemarks.borderStyle = UITextBorderStyle.None
alertController.addTextFieldWithConfigurationHandler (txtRemarks : UITextField!) -> Void in
txtRemarks.placeholder = "Enter Your Remarks"
txtRemarks.font = UIFont(name: (txtRemarks.font?.fontName)!, size: 15)
txtRemarks.userInteractionEnabled=true
txtRemarks.borderStyle = UITextBorderStyle.Line
txtRemarks.textAlignment = NSTextAlignment.Center
alertController.addAction(AUTHORISE)
alertController.addAction(DENY)
alertController.addAction(CANCEL)
self.presentViewController(alertController, animated: true, completion: nil)
【问题讨论】：
您可以先禁用按钮，然后实现文本字段委托方法来检查何时启用按钮。 【参考方案1】：将您的类设置为 UIAlertViewDelegate 并将您的 alrtView 的委托设置为您的类。
然后这样做
- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
if (buttonIndex == 1)
NSString *name = [alertView textFieldAtIndex:0].text;
// Here check for validation. If the text is empty disable button or however you would like to handle it
【讨论】：
这个问题被标记为 Swift，而不是 Objective-C。【参考方案2】： class ViewController: UIViewController,UITextFieldDelegate
override func viewDidLoad()
super.viewDidLoad()
// 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.
var authorizeaction:UIAlertAction?
@IBAction func tapBtnaction(sender: AnyObject)
let titleStr = "title"
let messageStr = "message"
let alert = UIAlertController(title: titleStr, message: messageStr, preferredStyle: UIAlertControllerStyle.Alert)
let placeholderStr = "Enter your Remarks"
alert.addTextFieldWithConfigurationHandler((textField: UITextField) in
textField.placeholder = placeholderStr
textField.addTarget(self, action: #selector(self.textChanged(_:)), forControlEvents: .EditingChanged)
)
let authorize = UIAlertAction(title: "Authorize", style: UIAlertActionStyle.Default, handler: (_) -> Void in
)
let deny = UIAlertAction(title: "Deny", style: UIAlertActionStyle.Default, handler: (_) -> Void in
let textfield = alert.textFields!.first!
//Do what you want with the textfield!
)
let cancel = UIAlertAction(title: "Cancel", style: UIAlertActionStyle.Cancel, handler: (_) -> Void in
let textfield = alert.textFields!.first!
//Do what you want with the textfield!
)
alert.addAction(cancel)
alert.addAction(authorize)
alert.addAction(deny)
//self.actionToEnable = action
authorizeaction = authorize
authorizeaction!.enabled = false
self.presentViewController(alert, animated: true, completion: nil)
func textChanged(sender:UITextField)
if sender.text?.characters.count > 0
authorizeaction?.enabled = true
else
authorizeaction?.enabled = false
Output:
编辑：
如果您不想启用或禁用授权操作，则可以使用以下代码。
let authorize = UIAlertAction(title: "Authorize", style: UIAlertActionStyle.Default, handler: (_) -> Void in
if let textfield : UITextField = alert.textFields![0]
if textfield.text?.characters.count == 0
//empty
self.presentViewController(alert, animated: true, completion:
let tempAlert = UIAlertController(title: "Error", message: "Please Enter remarks", preferredStyle: UIAlertControllerStyle.Alert)
tempAlert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.Cancel, handler: (action) in
))
alert.presentViewController(tempAlert, animated: true, completion: nil)
)
else
//authorize
)
仅显示消息的替代选项是 Toast。 https://github.com/scalessec/Toast
【讨论】：
你能解释一下这个“#selector(self.textChanged(_:))” @Jeesson_7 它与 TextField 委托方法 shouldChangeCharactersInRange 相同，它在文本字段中提供文本更改事件。 嘿，谢谢你的努力。问题是我在单击表格行时显示了此警报视图。我已将我的代码添加到我现在编辑的问题中。【参考方案3】：您需要将手势识别器添加到在解雇发生之前触发的 UIAlertController 为此，您可以参考以下答案： Prevent UIAlertController to dismiss
否则你可以使用下面的代码：
let alertController = UIAlertController(title: "OD Authorise", message: "", preferredStyle: UIAlertControllerStyle.alert)
let AUTHORISE = UIAlertAction(title: "AUTHORISE", style: UIAlertActionStyle.default, handler:
alert -> Void in
let firstTextField = alertController.textFields![4] as UITextField
if firstTextField.text?.count == 0
//print("Please enter your remark first")
SVProgressHUD.showError(withStatus: "Please enter your remark first")
self.present(alertController, animated: true, completion: nil)
return
print("<><><><><><>",firstTextField.text ?? "")
)
let DENY = UIAlertAction(title: "DENY", style: UIAlertActionStyle.default, handler:
(action : UIAlertAction!) -> Void in
)
let CANCEL = UIAlertAction(title: "CANCEL", style: UIAlertActionStyle.default, handler:
(action : UIAlertAction!) -> Void in
)
alertController.addTextField (txtRemarks : UITextField!) -> Void in
txtRemarks.font = UIFont(name: (txtRemarks.font?.fontName)!, size: 11)
txtRemarks.text = " Employee Name : YOUR ARRAY OBJECT"//\(self.empNameArr[indexPath.row]) "
txtRemarks.isUserInteractionEnabled=false
txtRemarks.borderStyle = UITextBorderStyle.none
alertController.addTextField (txtRemarks : UITextField!) -> Void in
txtRemarks.font = UIFont(name: (txtRemarks.font?.fontName)!, size: 11)
txtRemarks.text = " From Date : YOUR ARRAY OBJECT"//\(self.leavDateArr[indexPath.row]) "
txtRemarks.isUserInteractionEnabled=false
txtRemarks.borderStyle = UITextBorderStyle.none
alertController.addTextField (txtRemarks : UITextField!) -> Void in
txtRemarks.font = UIFont(name: (txtRemarks.font?.fontName)!, size: 11)
txtRemarks.text = " To Date : YOUR ARRAY OBJECT"//\(self.ToDate[indexPath.row]) "
txtRemarks.isUserInteractionEnabled=false
txtRemarks.borderStyle = UITextBorderStyle.none
alertController.addTextField (txtRemarks : UITextField!) -> Void in
txtRemarks.font = UIFont(name: (txtRemarks.font?.fontName)!, size: 11)
txtRemarks.text = " Leave reason : YOUR ARRAY OBJECT"//\(self.Reason[indexPath.row]) "
txtRemarks.isUserInteractionEnabled=false
txtRemarks.borderStyle = UITextBorderStyle.none
alertController.addTextField (txtRemarks : UITextField!) -> Void in
txtRemarks.placeholder = "Enter Your Remarks"
txtRemarks.font = UIFont(name: (txtRemarks.font?.fontName)!, size: 15)
txtRemarks.isUserInteractionEnabled=true
txtRemarks.borderStyle = UITextBorderStyle.line
txtRemarks.textAlignment = NSTextAlignment.center
alertController.addAction(AUTHORISE)
alertController.addAction(DENY)
alertController.addAction(CANCEL)
self.present(alertController, animated: true, completion: nil)
【讨论】：
以上是关于有没有一种方法可以使用 swift 在 alertview 内的文本字段中提供验证的主要内容，如果未能解决你的问题，请参考以下文章
IOS swift TableView有没有一种方法可以重用它们