问题
Below is the code that I'm trying to use to have the view scroll only when the focused textField or UIButton is hidden by the keyboard:
import UIKit
class ViewController: UIViewController, UITextFieldDelegate {
@IBOutlet weak var buttonToBottomConstraint: NSLayoutConstraint!
@IBOutlet weak var textFieldUsername: UITextField!
@IBOutlet weak var textFieldPassword: UITextField!
@IBOutlet weak var scrollView: UIScrollView!
override func viewDidLoad() {
super.viewDidLoad()
NSNotificationCenter.defaultCenter().addObserver(self, selector:"keyboardWillBeHidden:", name: UIKeyboardWillHideNotification, object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector:"keyboardWillBeShown:", name: UIKeyboardWillShowNotification, object: nil)
}
func textFieldDidBeginEditing(textField: UITextField) {
}
func textFieldShouldReturn(textField: UITextField) -> Bool {textField.resignFirstResponder()
return true
}
func keyboardWillBeHidden(notification: NSNotification){
self.scrollView.setContentOffset(CGPointMake(0, 0), animated: true)
}
func keyboardWillBeShown(notification: NSNotification){
let userInfo = notification.userInfo!
if let kbsize = userInfo[UIKeyboardFrameBeginUserInfoKey]?.CGRectValue().size{
self.scrollView .setContentOffset(CGPointMake(0, kbsize.or), animated: true)
}
}
}
Problem: The View scrolls even when the keyboard is not hiding anything.
View at Launch:
View Upon Tapping on a TextField:
Question: How do I check to see if the focused field is hidden by the keyboard, and ONLY if it is, push it above it?
Project: TextFieldScroll
EDIT
App works fine in Portrait mode, however, not in landscape mode. Also in landscape mode, when the Username textField keyboard is up and I tap the Password textField, it remains hidden behind the keyboard. I updated the project on Github and fixed the link. Thanks
Screen shot in landscape:
回答1:
var currentTextField:UITextField?
@IBOutlet weak var textFieldUsername: UITextField!
@IBOutlet weak var textFieldPassword: UITextField!
@IBOutlet weak var scrollView: UIScrollView!
override func viewDidLoad()
{
super.viewDidLoad()
NSNotificationCenter.defaultCenter().addObserver(self, selector:"keyboardWillBeHidden:", name: UIKeyboardWillHideNotification, object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector:"keyboardWillBeShown:", name: UIKeyboardWillShowNotification, object: nil)
}
func textFieldDidBeginEditing(textField: UITextField)
{
currentTextField=textField;
}
func textFieldShouldReturn(textField: UITextField) -> Bool {
textField.resignFirstResponder()
return true
}
func keyboardWillBeHidden(notification: NSNotification){
currentTextField=nil;
self.scrollView.setContentOffset(CGPointMake(0, 0), animated: true)
}
func keyboardWillBeShown(notification: NSNotification){
let userInfo = notification.userInfo!
if let kbsize = userInfo[UIKeyboardFrameBeginUserInfoKey]?.CGRectValue().size
{
let contentInsets = UIEdgeInsets(top: 0, left: 0, bottom: kbsize.height, right: 0)
let screenSize: CGRect = UIScreen.mainScreen().bounds
let screenHeight = screenSize.height
let height:CGFloat=screenHeight-(kbsize.height)-(currentTextField!.frame.size.width)
if(currentTextField!.frame.origin.y>=height )
{
var scrollPoint: CGPoint = CGPointMake(0.0, currentTextField!.frame.origin.y - (kbsize.height));
self.scrollView .setContentOffset(scrollPoint, animated: true)
}
}
}
func textFieldDidEndEditing(textField: UITextField) {
currentTextField=nil;
}
回答2:
I don't see you setting the scrollView's contentSize. Thus, the scrollView scrolls with the keyboard since it uses the screen's size.
来源：https://stackoverflow.com/questions/32063357/swift-scroll-view-only-when-a-textfield-or-button-is-hidden-by-the-keyboard