使用iOS SDK：
我有一个带UITextFields的UIView，可以启动键盘。我需要它能够：
启动键盘后，允许滚动UIScrollView的内容以查看其他文本字段自动“跳转”（通过向上滚动）或缩短
我知道我需要一个UIScrollView。我已经尝试将UIView的类更改为UIScrollView，但仍然无法上下滚动文本框。
我需要UIView和UIScrollView吗？一个在另一个里面吗？
要自动滚动到活动文本字段，需要执行哪些操作？
理想情况下，尽可能多的组件设置将在Interface Builder中完成。我只想编写需要的代码。
注意：我使用的UIView（或UIScrollView）是由一个选项卡（UITabBar）启动的，它需要正常工作。
我正在添加滚动条，只为键盘出现时使用。尽管不需要它，但我觉得它提供了一个更好的界面，例如，用户可以滚动和更改文本框。
当键盘上下移动时，我可以改变UIScrollView的框架大小。我只是在使用：
-(void)textFieldDidBeginEditing:(UITextField *)textField {
//Keyboard becomes visible
scrollView.frame = CGRectMake(scrollView.frame.origin.x,
scrollView.frame.origin.y,
scrollView.frame.size.width,
scrollView.frame.size.height - 215 + 50); // Resize
}
-(void)textFieldDidEndEditing:(UITextField *)textField {
// Keyboard will hide
scrollView.frame = CGRectMake(scrollView.frame.origin.x,
scrollView.frame.origin.y,
scrollView.frame.size.width,
scrollView.frame.size.height + 215 - 50); // Resize
}
然而，这不会自动“向上移动”或将可见区域中的下部文本字段居中，这是我真正想要的。
这是使用Swift的解决方案。
import UIKit
class ExampleViewController: UIViewController, UITextFieldDelegate {
@IBOutlet var scrollView: UIScrollView!
@IBOutlet var textField1: UITextField!
@IBOutlet var textField2: UITextField!
@IBOutlet var textField3: UITextField!
@IBOutlet var textField4: UITextField!
@IBOutlet var textField5: UITextField!
var activeTextField: UITextField!
// MARK: - View
override func viewDidLoad() {
super.viewDidLoad()
self.textField1.delegate = self
self.textField2.delegate = self
self.textField3.delegate = self
self.textField4.delegate = self
self.textField5.delegate = self
}
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
self.registerForKeyboardNotifications()
}
override func viewWillDisappear(animated: Bool) {
super.viewWillDisappear(animated)
self.unregisterFromKeyboardNotifications()
}
// MARK: - Keyboard
// Call this method somewhere in your view controller setup code.
func registerForKeyboardNotifications() {
let center: NSNotificationCenter = NSNotificationCenter.defaultCenter()
center.addObserver(self, selector: "keyboardWasShown:", name: UIKeyboardDidShowNotification, object: nil)
center.addObserver(self, selector: "keyboardWillBeHidden:", name: UIKeyboardWillHideNotification, object: nil)
}
func unregisterFromKeyboardNotifications () {
let center: NSNotificationCenter = NSNotificationCenter.defaultCenter()
center.removeObserver(self, name: UIKeyboardDidShowNotification, object: nil)
center.removeObserver(self, name: UIKeyboardWillHideNotification, object: nil)
}
// Called when the UIKeyboardDidShowNotification is sent.
func keyboardWasShown (notification: NSNotification) {
let info : NSDictionary = notification.userInfo!
let kbSize = (info.objectForKey(UIKeyboardFrameBeginUserInfoKey)?.CGRectValue() as CGRect!).size
let contentInsets: UIEdgeInsets = UIEdgeInsetsMake(0.0, 0.0, kbSize.height, 0.0);
scrollView.contentInset = contentInsets;
scrollView.scrollIndicatorInsets = contentInsets;
// If active text field is hidden by keyboard, scroll it so it's visible
// Your app might not need or want this behavior.
var aRect = self.view.frame
aRect.size.height -= kbSize.height;
if (!CGRectContainsPoint(aRect, self.activeTextField.frame.origin) ) {
self.scrollView.scrollRectToVisible(self.activeTextField.frame, animated: true)
}
}
// Called when the UIKeyboardWillHideNotification is sent
func keyboardWillBeHidden (notification: NSNotification) {
let contentInsets = UIEdgeInsetsZero;
scrollView.contentInset = contentInsets;
scrollView.scrollIndicatorInsets = contentInsets;
}
// MARK: - Text Field
func textFieldDidBeginEditing(textField: UITextField) {
self.activeTextField = textField
}
func textFieldDidEndEditing(textField: UITextField) {
self.activeTextField = nil
}
}
Swift 2.0版本：
添加UIScrollView并在其顶部添加textFields。将故事板引用到VC。
@IBOutlet weak var username: UITextField!
@IBOutlet weak var password: UITextField!
@IBOutlet weak var scrollView: UIScrollView!
添加以下方法：UITextFieldDelegate和UIScrollViewDelegate。
//MARK:- TEXTFIELD METHODS
func textFieldShouldReturn(textField: UITextField) -> Bool {
if(username.returnKeyType == UIReturnKeyType.Default) {
password.becomeFirstResponder()
}
textField.resignFirstResponder()
return true
}
func textFieldDidBeginEditing(textField: UITextField) {
dispatch_async(dispatch_get_main_queue()) {
let scrollPoint:CGPoint = CGPointMake(0,textField.frame.origin.y/4)
self.scrollView!.setContentOffset(scrollPoint, animated: true);
}
}
func textFieldShouldEndEditing(textField: UITextField) -> Bool {
dispatch_async(dispatch_get_main_queue()) {
UIView.animateWithDuration(0, animations: { self.scrollView!.setContentOffset(CGPointZero,animated: true) })
}
return true
}
override func touchesBegan(touches: Set<UITouch>,
withEvent event: UIEvent?) {
self.view.endEditing(true)
}
func scrollViewWillBeginDragging(scrollView: UIScrollView) {
self.scrollView.scrollEnabled = true
dispatch_async(dispatch_get_main_queue()) {
UIView.animateWithDuration(0, animations: { self.scrollView!.setContentOffset(CGPointZero,animated: true)
})
}
}
在textFieldDidBginEditing和textFieldDidEndEditing中调用函数[self-animateTextField:textField up:YES]，如下所示：
-(void)textFieldDidBeginEditing:(UITextField *)textField
{
[self animateTextField:textField up:YES];
}
- (void)textFieldDidEndEditing:(UITextField *)textField
{
[self animateTextField:textField up:NO];
}
-(void)animateTextField:(UITextField*)textField up:(BOOL)up
{
const int movementDistance = -130; // tweak as needed
const float movementDuration = 0.3f; // tweak as needed
int movement = (up ? movementDistance : -movementDistance);
[UIView beginAnimations: @"animateTextField" context: nil];
[UIView setAnimationBeginsFromCurrentState: YES];
[UIView setAnimationDuration: movementDuration];
self.view.frame = CGRectOffset(self.view.frame, 0, movement);
[UIView commitAnimations];
}
我希望这段代码对你有所帮助。
雨燕5
func animateTextField(textField: UITextField, up: Bool) {
let movementDistance: CGFloat = -130
let movementDuration: Double = 0.3
var movement:CGFloat = 0
if up {
movement = movementDistance
} else {
movement = -movementDistance
}
UIView.animate(withDuration: movementDuration, delay: 0, options: [.beginFromCurrentState]) {
self.view.frame = self.view.frame.offsetBy(dx: 0, dy: movement)
}
}
func textFieldDidBeginEditing(_ textField: UITextField) {
animateTextField(textField: textField, up: true)
}
func textFieldDidEndEditing(_ textField: UITextField) {
animateTextField(textField: textField, up: false)
}
这是我的“仅UITextView扩展”解决方案，基于Paul Hudson@twostraws的解决方案（向他和这里所有类似答案的作者致敬）。
import UIKit
extension UITextView {
func adjustableForKeyboard() {
let notificationCenter = NotificationCenter.default
notificationCenter.addObserver(self, selector: #selector(adjustForKeyboard), name: UIResponder.keyboardWillHideNotification, object: nil)
notificationCenter.addObserver(self, selector: #selector(adjustForKeyboard), name: UIResponder.keyboardWillChangeFrameNotification, object: nil)
}
@objc private func adjustForKeyboard(notification: Notification) {
guard let keyboardValue = notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue else {
return
}
let keyboardScreenEndFrame = keyboardValue.cgRectValue
let keyboardViewEndFrame = convert(keyboardScreenEndFrame, from: window)
if notification.name == UIResponder.keyboardWillHideNotification {
contentInset = .zero
} else {
contentInset = UIEdgeInsets(top: 0, left: 0, bottom: keyboardViewEndFrame.height - safeAreaInsets.bottom, right: 0)
}
scrollIndicatorInsets = contentInset
scrollRangeToVisible(selectedRange)
}
}
用法：
override func viewDidLoad() {
super.viewDidLoad()
textView.adjustableForKeyboard()
}
