通过 UiscrollView 快速滚动到 UITextField 仅作为第一次错误
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【中文标题】通过 UiscrollView 快速滚动到 UITextField 仅作为第一次错误【英文标题】：Swift Scroll to UITextField via UiscrollView only acts first time bug 【发布时间】：2017-10-14 15:58:12 【问题描述】：我在这里发布我的完整代码。问题是最初加载应用程序和视图控制器时。它完全有效。点击两个文本字段，滚动视图向上推，键盘位于当前文本字段下方。但是，如果点击文本字段.. 向上移动视图并在文本字段上重复，它就不再这样做了。此外，如果通过导航控制器返回然后再次加载此视图控制器，它不会做任何事情。它不再滚动了..（不再向上推动文本字段并且键盘在它下方）...
import UIKit
import Parse
import Alamofire
import SwiftyJSON
class VCreservacion: UIViewController,UITextFieldDelegate,UIScrollViewDelegate
var SUCURSALID = 0
var EMP_NOMBRE = ""
var DIRECCION = ""
var PROVINCIA = ""
var RESTID = 20556
@IBOutlet var lbl_empresa: UILabel!
@IBOutlet var lbl_direccion: UILabel!
@IBOutlet var lbl_step: UILabel!
@IBOutlet var cantidadView: UIView!
@IBOutlet var datePicker: UIDatePicker!
@IBOutlet var btn_reservar: UIButton!
@IBOutlet var stackView: UIStackView!
@IBOutlet var scrollView: UIScrollView!
@IBOutlet var txtComentario: UITextField!
@IBOutlet weak var txtCelular: UITextField!
var activeField: UITextField?
var steps = 2
// MARK: RESERVE ACTION
@IBAction func ReserveAction(_ sender: UIButton)
print("Reservando...")
// For date formater
var dateformated = ""
var dateformated2 = ""
let formatter = DateFormatter()
formatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
//formatter.timeZone = NSTimeZone(forSecondsFromGMT: 0) as TimeZone!
dateformated = formatter.string(from: datePicker.clampedDate)
dateformated2 = formatter.string(from: datePicker.date)
print(dateformated)
print(dateformated2)
let cart = Cart.sharedInstance
guard let user = PFUser.current() else
cart.showAlertView("Login", message: "Debes estar logeado para poder reservar.")
return
Alamofire.request("URL String", parameters: ["qty": "\(steps)","sucursalid":"\(self.SUCURSALID)","restid":"\(RESTID)","comment":"\(txtComentario.text!)","phone":"\(txtCelular.text!)","datetime":"\(dateformated)","action":"request","userid":"\(user.objectId!)"]).authenticate(usingCredential: cart.credential).responseJSON()
response in
if (response.error != nil )
print(response.error.debugDescription)
print(response.request)
cart.showAlertView("Error", message: "there was an error.")
if(response.result.value != nil)
let json = JSON(response.result.value!);
print(json);
let success:Bool = json["success"].boolValue
let error: Bool = json["error"].boolValue
if(success)
print("con exito")
let alert = UIAlertController(title: "Reserva Enviada", message: "Tu reserva ha sido enviada y será revisada por el establecimiento", preferredStyle: .alert)
let okAction = UIAlertAction(title: "OK", style: UIAlertActionStyle.default)
UIAlertAction in
// Get the previous Controller.
let targetController: UIViewController = (self.navigationController?.viewControllers[self.navigationController!.viewControllers.count - 3])!
// And go to that Controller
self.navigationController?.popToViewController(targetController, animated: true)
alert.addAction(okAction)
self.present(alert,animated:true)
@IBAction func stepperValue(_ sender: UIStepper)
self.lbl_step.text = Int(sender.value).description
steps = Int(sender.value)
override func viewWillAppear(_ animated: Bool)
super.viewWillAppear(animated)
registerForKeyboardNotifications()
self.scrollView.delegate = self
override func viewWillDisappear(_ animated: Bool)
super.viewWillDisappear(animated)
deregisterFromKeyboardNotifications()
self.scrollView.delegate = nil
// MARK: Viewdidload
override func viewDidLoad()
super.viewDidLoad()
// enable scroll on scrollview
self.scrollView.isScrollEnabled = true
// step label initial value 2
self.lbl_step.text = "2"
// Get celular or phone
if ( Cart.sharedInstance.User_celular != "")
txtCelular.text = Cart.sharedInstance.User_celular
else
txtCelular.text = Cart.sharedInstance.User_phone
let nearesthour = Date().nearestHour()
self.datePicker.minimumDate = nearesthour
self.txtComentario.delegate = self
self.txtCelular.delegate = self
self.txtCelular.tag = 20
self.scrollView.delegate = self
// tap gesture recognizer
let tap = UITapGestureRecognizer(target: self, action: #selector(handleTap(_:)))
self.scrollView.addGestureRecognizer(tap)
print("el enarest hour es \(nearesthour as Date?) y el date normal es \(Date())")
self.btn_reservar.layer.cornerRadius = 10
self.cantidadView.layer.cornerRadius = 10
self.lbl_empresa.text = EMP_NOMBRE
self.lbl_direccion.text = DIRECCION
/*
print("VC Reservacion")
print("SUCURSAL \(SUCURSALID) ")
print("EMP NOMBRE " + EMP_NOMBRE)
print("DIRECCION " + DIRECCION)
*/
// MARK: TEXTFIELD STUFF
func textFieldShouldBeginEditing(_ textField: UITextField) -> Bool
self.activeField = textField
return true
/*
func textFieldDidBeginEditing(_ textField: UITextField)
self.activeField = textField
*/
func textFieldDidEndEditing(_ textField: UITextField)
activeField = nil
func registerForKeyboardNotifications()
//Adding notifies on keyboard appearing
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWasShown(notification:)), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillBeHidden(notification:)), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
func deregisterFromKeyboardNotifications()
//Removing notifies on keyboard appearing
NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillHide, object: nil)
@objc func keyboardWasShown(notification: NSNotification)
//Need to calculate keyboard exact size due to Apple suggestions
print(" Keyboaard shown")
var info = notification.userInfo!
let keyboardSize = (info[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue.size
print(" el keyboardsize is \(keyboardSize)")
let contentInsets : UIEdgeInsets = UIEdgeInsetsMake(0.0, 0.0, keyboardSize!.height + 80, 0.0)
self.scrollView.contentInset = contentInsets
self.scrollView.scrollIndicatorInsets = contentInsets
var aRect : CGRect = self.view.frame
print("VIEW COMPLETE FRAME IS \(aRect)")
print("KEYBOARD FRAME HEIGHT \(keyboardSize!.height)")
aRect.size.height -= keyboardSize!.height
print("FRAME MENOS KEYBOARD ES \(aRect)")
print("SCROLLVIEW CONTENT \(self.scrollView.contentSize)")
if let activeField = self.activeField
print("ACTIVEFIELD FRAME ORIGIN \(activeField.frame.origin) ")
print("Active field is textfield tag is \(activeField.tag)")
// if (!aRect.contains(activeField.frame.origin))
print("arect Does Not contains activeField")
self.scrollView.scrollRectToVisible(activeField.frame, animated: true)
print("TEXTFIELD FRAME ES \(activeField.frame)")
print(" SCROLLVIEW CONTENT \(self.scrollView.contentSize)")
//
@objc func keyboardWillBeHidden(notification: NSNotification)
//Once keyboard disappears, restore original positions
var info = notification.userInfo!
let keyboardSize = (info[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue.size
let contentInsets : UIEdgeInsets = UIEdgeInsetsMake(0.0, 0.0, -keyboardSize!.height, 0.0)
self.scrollView.contentInset = contentInsets
self.scrollView.scrollIndicatorInsets = contentInsets
self.activeField = nil
self.view.endEditing(true)
self.scrollView.isScrollEnabled = false
@objc func handleTap(_ sender: UITapGestureRecognizer)
self.view.endEditing(true)
print("Tap")
func textFieldShouldReturn(_ textField: UITextField) -> Bool
self.view.endEditing(true)
return false
override func viewDidLayoutSubviews()
super.viewDidLayoutSubviews()
scrollView.contentSize = CGSize(width: view.frame.width, height: view.frame.height)
print(" SCROLLVIEW CONTENT AFTER SUBVIEWS \(self.scrollView.contentSize)")
/* // NOT WORKING BECAUSE OF UISCROLLVIEW IN PLACE, MUST USE UITAPGESTURE RECOGNIZER
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?)
self.view.endEditing(true)
self.activeField?.resignFirstResponder()
*/
【问题讨论】：
【参考方案1】：我遇到了同样的问题。显然，获取键盘的大小发生了变化。我将 UIKeyboardFrameBeginUserInfoKey 更改为 UIKeyboardFrameEndUserInfoKey 并让它再次工作。
这是我在按下文本字段时移动视图的确切代码
@objc func keyboardWasShown(notification: NSNotification)
self.scrollView.isScrollEnabled = true
var info = notification.userInfo!
let keyboardSize = (info[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue.size
let contentInsets = UIEdgeInsetsMake(0.0, 0.0, keyboardSize!.height, 0.0)
self.scrollView.contentInset = contentInsets
self.scrollView.scrollIndicatorInsets = contentInsets
var aRect : CGRect = self.view.frame
guard let kbHeight = keyboardSize?.height elsereturn
aRect.size.height -= kbHeight
if let activeField = self.activeTextField
if (!aRect.contains(activeField.frame.origin))
self.scrollView.scrollRectToVisible(activeField.frame, animated: true)
【讨论】：
嗯..让我试试！！以上是关于通过 UiscrollView 快速滚动到 UITextField 仅作为第一次错误的主要内容，如果未能解决你的问题，请参考以下文章