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。
这是我为特定布局想出的破解方案。此解决方案与Matt Gallagher的解决方案相似,即将一个部分滚动到视图中。我还是iPhone开发的新手,不熟悉布局的工作原理。因此,这个黑客。
我的实现需要支持在字段中单击时滚动,以及用户在键盘上选择下一个时滚动。
我有一个UIView,身高775。控件基本上以3人一组的方式分布在一个大的空间中。我最终得到了以下IB布局。
UIView -> UIScrollView -> [UI Components]
黑客来了
我将UIScrollView的高度设置为比实际布局(1250)大500个单位。然后,我创建了一个数组,其中包含我需要滚动到的绝对位置,以及一个基于IB标记号获取它们的简单函数。
static NSInteger stepRange[] = {
0, 0, 0, 0, 0, 0, 0, 0, 0, 140, 140, 140, 140, 140, 410
};
NSInteger getScrollPos(NSInteger i) {
if (i < TXT_FIELD_INDEX_MIN || i > TXT_FIELD_INDEX_MAX) {
return 0 ;
return stepRange[i] ;
}
现在,您需要做的就是在textFieldDidBeginEditing和textFieldShouldReturn中使用以下两行代码(如果要创建下一个字段导航,则使用后者)
CGPoint point = CGPointMake(0, getScrollPos(textField.tag)) ;
[self.scrollView setContentOffset:point animated:YES] ;
一个例子。
- (void) textFieldDidBeginEditing:(UITextField *)textField
{
CGPoint point = CGPointMake(0, getScrollPos(textField.tag)) ;
[self.scrollView setContentOffset:point animated:YES] ;
}
- (BOOL)textFieldShouldReturn:(UITextField *)textField {
NSInteger nextTag = textField.tag + 1;
UIResponder* nextResponder = [textField.superview viewWithTag:nextTag];
if (nextResponder) {
[nextResponder becomeFirstResponder];
CGPoint point = CGPointMake(0, getScrollPos(nextTag)) ;
[self.scrollView setContentOffset:point animated:YES] ;
}
else{
[textField resignFirstResponder];
}
return YES ;
}
此方法不像其他方法那样“向后滚动”。这不是必需的。同样,这是一个相当“高大”的UIView,我没有时间学习内部布局引擎。
Swift 3.0版本的苹果键盘管理代码如下:以下代码中使用的FloatingTF是iOS中基于材质设计的文本字段。
import UIKit
class SignupViewController: UIViewController, UITextFieldDelegate {
//MARK: - IBOutlet:
@IBOutlet weak var emailTF: FloatingTF!
@IBOutlet weak var passwordTF: FloatingTF!
@IBOutlet weak var dobTF: FloatingTF!
@IBOutlet weak var scrollView: UIScrollView!
//MARK: - Variable:
var activeTextField: UITextField!
//MARK: - ViewController Lifecycle:
override func viewDidLoad() {
super.viewDidLoad()
emailTF.delegate = self
passwordTF.delegate = self
dobTF.delegate = self
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
registerKeyboardNotifications()
}
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
deRegisterKeyboardNotifications()
}
//MARK: - Keyboard notification observer Methods
fileprivate func registerKeyboardNotifications() {
NotificationCenter.default.addObserver(self, selector: #selector(SignupViewController.keyboardWillShow), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(SignupViewController.keyboardWillHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}
fileprivate func deRegisterKeyboardNotifications() {
NotificationCenter.default.removeObserver(self, name: .UIKeyboardWillShow, object: self.view.window)
NotificationCenter.default.removeObserver(self, name: .UIKeyboardDidHide, object: self.view.window)
}
func keyboardWillShow(notification: NSNotification) {
let info: NSDictionary = notification.userInfo! as NSDictionary
let value: NSValue = info.value(forKey: UIKeyboardFrameBeginUserInfoKey) as! NSValue
let keyboardSize: CGSize = value.cgRectValue.size
let contentInsets: UIEdgeInsets = UIEdgeInsetsMake(0.0, 0.0, keyboardSize.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: CGRect = self.view.frame
aRect.size.height -= keyboardSize.height
let activeTextFieldRect: CGRect? = activeTextField?.frame
let activeTextFieldOrigin: CGPoint? = activeTextFieldRect?.origin
if (!aRect.contains(activeTextFieldOrigin!)) {
scrollView.scrollRectToVisible(activeTextFieldRect!, animated:true)
} }
func keyboardWillHide(notification: NSNotification) {
let contentInsets: UIEdgeInsets = .zero
scrollView.contentInset = contentInsets
scrollView.scrollIndicatorInsets = contentInsets
}
//MARK: - UITextField Delegate Methods
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
if textField == emailTF {
passwordTF.becomeFirstResponder()
}
else if textField == passwordTF {
dobTF.becomeFirstResponder()
}
else {
self.view.endEditing(true)
}
return true
}
func textFieldDidBeginEditing(_ textField: UITextField) {
activeTextField = textField
scrollView.isScrollEnabled = true
}
func textFieldDidEndEditing(_ textField: UITextField) {
activeTextField = nil
scrollView.isScrollEnabled = false
}
}
在(BOOL)textFieldShouldBeginEditing:(UITextField*)textField中
if (textField.frame.origin.y > self.view.frame.size.height - 216)
{
if (screenHeight>500)
scrollView.contentSize = CGSizeMake(0.0, scrollView.contentSize.height + 100);
else
scrollView.contentSize = CGSizeMake(0.0, scrollView.contentSize.height + 216);
CGPoint scrollPoint = CGPointMake(0.0,(textField.frame.origin.y - (self.view.frame.size.height - 216 - textField.frame.size.height - 20)));
[scrollView setContentOffset:scrollPoint animated:YES];
}
[scrollView setScrollEnabled:YES];
辞职时,你需要写以下代码
scrollView.contentSize = CGSizeMake(0.0, 640);
CGPoint scrollPoint = CGPointMake(0.0,0.0);
[scrollView setContentOffset:scrollPoint animated:YES];
雨燕5
在viewDidLoad或viewDidAppear中添加addKeyboardObserver方法。
fileprivate func addKeyboardObservers(){
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow), name: UIResponder.keyboardWillShowNotification, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide), name: UIResponder.keyboardWillHideNotification, object: nil)
}
fileprivate func removeKeyboardObservers(){
NotificationCenter.default.removeObserver(self, name: UIResponder.keyboardWillHideNotification, object: nil)
NotificationCenter.default.removeObserver(self, name: UIResponder.keyboardWillShowNotification, object: nil)
}
@objc fileprivate func keyboardWillHide(_ notification: Notification){
if (window == nil) {return}
guard let duration = (notification.userInfo?[UIResponder.keyboardAnimationDurationUserInfoKey] as? Double) else {return}
scrollView.contentInset.bottom = .zero
}
@objc fileprivate func keyboardWillShow(_ notification: Notification){
if (window == nil) {return}
if UIApplication.shared.applicationState != .active { return }
// keyboard height
guard let height = (notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? CGRect)?.height else {return}
// keyboard present animation duration
guard let duration = (notification.userInfo?[UIResponder.keyboardAnimationDurationUserInfoKey] as? Double) else {return}
scrollView.contentInset.bottom = height
}
不要忘记删除或消失观察者
self.removeKeyboardObservers()