这是我当前的代码，它可以工作，但是在较小的设备上，字段会移动到用户显示上方。我如何编辑它以确保这些字段不会对用户隐藏？我从 gregbarbosa 的 tut 中窃取了一些代码，因此带答案的解释会很有帮助。谢谢。
import UIKit
class LoginViewController: UIViewController {
//MARK: Storyboard
@IBOutlet weak var scrollView: UIScrollView!
@IBOutlet weak var teamID: UITextField!
@IBOutlet weak var scoutID: UITextField!
@IBOutlet weak var pinNum: UITextField!
@IBOutlet weak var signin: UIButton!
@IBOutlet weak var diamondPic: UIImageView!
@IBOutlet weak var nodextext: UILabel!
@IBOutlet weak var loginB: UIButton!
@IBOutlet weak var moverL: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
let tapGesture: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: "hideKeyboard")
// prevents the scroll view from swallowing up the touch event of child buttons
tapGesture.cancelsTouchesInView = false
scrollView.addGestureRecognizer(tapGesture)
}
@IBAction func loginTapped(sender: UIButton) {
var userDefaults = NSUserDefaults.standardUserDefaults()
var secretKey = userDefaults.stringForKey("secretkey")
var team:String = teamID.text
var scout:String = scoutID.text
var password:String = pinNum.text
var loginQuery = PFQuery(className:"User")
loginQuery.whereKey("teamID", equalTo:team)
loginQuery.whereKey("scoutID", equalTo:scout)
loginQuery.whereKey("password", equalTo:password)
loginQuery.findObjectsInBackgroundWithBlock {
(objects: [AnyObject]!, error: NSError!) -> Void in
if error == nil && objects.count != 0 {
self.performSegueWithIdentifier("SecondViewController", sender: self)
} else if error == nil && objects.count == 0{
var alert : UIAlertView = UIAlertView(title: "Login Error", message: "Your TeamID, ScoutID, or Password is inncorrect.", delegate: nil, cancelButtonTitle: "Ok")
alert.show()
} else {
// Log details of the failure
NSLog("Error: %@ %@", error, error.userInfo!)
}
}
}
@IBOutlet weak var loginTapped: UIButton!
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(true)
self.registerForKeyboardNotifications()
}
override func viewWillDisappear(animated: Bool) {
self.deregisterFromKeyboardNotifications()
super.viewWillDisappear(true)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
func registerForKeyboardNotifications() -> Void {
NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWasShown:", name: UIKeyboardDidShowNotification, object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWasShown:", name: UIKeyboardWillShowNotification, object: nil)
}
func deregisterFromKeyboardNotifications() -> Void {
println("Deregistering!")
NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWasShown:", name: UIKeyboardDidHideNotification, object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWasShown:", name: UIKeyboardWillHideNotification, object: nil)
}
func keyboardWasShown(notification: NSNotification) {
var info: Dictionary = notification.userInfo!
var keyboardSize: CGSize = (info[UIKeyboardFrameBeginUserInfoKey]?.CGRectValue().size)!
var buttonOrigin: CGPoint = self.loginB.frame.origin;
var buttonHeight: CGFloat = self.loginB.frame.size.height;
var visibleRect: CGRect = self.view.frame
visibleRect.size.height -= keyboardSize.height
if (!CGRectContainsPoint(visibleRect, buttonOrigin)) {
var scrollPoint: CGPoint = CGPointMake(0.0, buttonOrigin.y - visibleRect.size.height + buttonHeight + 4)
self.scrollView.setContentOffset(scrollPoint, animated: true)
}
nodextext.hidden = true
diamondPic.hidden = true
}
func hideKeyboard() {
teamID.resignFirstResponder() //FirstResponder's must be resigned for hiding keyboard.
scoutID.resignFirstResponder()
pinNum.resignFirstResponder()
self.scrollView.setContentOffset(CGPointZero, animated: true)
diamondPic.hidden = false
nodextext.hidden = false
}
}
先谢谢你。
最佳答案
有几种方法可以做到这一点。首先，当 UI 元素成为第一响应者时，您可以手动更改 ScrollView 的内容偏移量。您可以使用 UITextFieldDelegate 和 textFieldDidBeginEditing: 方法进行检查。这通常被证明是困难的。另一件事是将所有 UI 元素放在 TableView 中，并在文本字段等 UIElement 成为第一响应者时调用 scrollToRowAtIndexPath:atScrollPosition:animated:。
关于ios - 键盘打开时以编程方式提升 UI 文本字段，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/28180899/