当键盘出现时，如何在开始编辑时使UITextField上移？

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。

当前回答

使用ViewModifier快速切换UI

可以使用SwiftUI的ViewModifier。这要简单得多。

import SwiftUI
import Combine

struct KeyboardAwareModifier: ViewModifier {
    @State private var keyboardHeight: CGFloat = 0

    private var keyboardHeightPublisher: AnyPublisher<CGFloat, Never> {
        Publishers.Merge(
            NotificationCenter.default
                .publisher(for: UIResponder.keyboardWillShowNotification)
                .compactMap { $0.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue }
                .map { $0.cgRectValue.height },
            NotificationCenter.default
                .publisher(for: UIResponder.keyboardWillHideNotification)
                .map { _ in CGFloat(0) }
       ).eraseToAnyPublisher()
    }

    func body(content: Content) -> some View {
        content
            .padding(.bottom, keyboardHeight)
            .onReceive(keyboardHeightPublisher) { self.keyboardHeight = $0 }
    }
}

extension View {
    func KeyboardAwarePadding() -> some View {
        ModifiedContent(content: self, modifier: KeyboardAwareModifier())
    }
}

在你看来

struct SomeView: View {
    @State private var someText: String = ""

    var body: some View {
        VStack {
            Spacer()
            TextField("some text", text: $someText)
        }.KeyboardAwarePadding()
    }
}

KeyboardAwarePadding（）将自动为视图添加填充。它更优雅。

2020-01-04 16:59:07

其他回答

从以下链接下载TPKeyBoardAvoiding：https://github.com/michaeltyson/TPKeyboardAvoiding. 展开zipped文件夹，找到TPKeyboardAvoiding文件夹。选择所有.h和.m文件，并将其放到项目中。确保选中了复制项（如果需要）。将UIScrollView拖放到StoryBoard并与TPKeyboardAvoidingScrollView关联。现在，您可以在滚动视图的顶部添加UI元素。注意，即使在拖动scrollView之后，这个类也会检测UI元素的触摸。

在ViewController上：

@IBOutlet weak var usernameTextfield: UITextField!
@IBOutlet weak var passwordTextfield: UITextField!
@IBOutlet weak var loginScrollView: UIScrollView!


override func viewWillAppear(animated: Bool) {
        loginScrollView.scrollEnabled =  false
    }

添加TextField委托。

//MARK:- TEXTFIELD METHODS
func textFieldShouldReturn(textField: UITextField) -> Bool
{
    if (usernameTextfield.resignFirstResponder())
    {
        passwordTextfield.becomeFirstResponder()
    }
    textField.resignFirstResponder();
    loginScrollView!.setContentOffset(CGPoint.zero, animated: true);
    loginScrollView.scrollEnabled =  false
    return true
}
func textFieldDidBeginEditing(textField: UITextField)
{
    loginScrollView.scrollEnabled =  true

    if (textField.tag  == 1 && (device == "iPhone" || device == "iPhone Simulator" || device == "iPod touch"))
    {
        let scrollPoint:CGPoint = CGPointMake(0, passwordTextfield.frame.origin.y/6.4);
        loginScrollView!.setContentOffset(scrollPoint, animated: true);

    }
    else if (textField.tag  == 2 && (device == "iPhone" || device == "iPhone Simulator" || device == "iPod touch"))
    {
        let scrollPoint:CGPoint = CGPointMake(0, passwordTextfield.frame.origin.y/6.0);
        loginScrollView!.setContentOffset(scrollPoint, animated: true);
    }
}
func textFieldDidEndEditing(textField: UITextField)
{
    loginScrollView!.setContentOffset(CGPointZero,animated: true);
}

2016-05-30 10:25:38

您也可以使用textfield委托方法。检查以下代码。当将文本字段放在滚动视图上时，它对我很有用。

- (void)textFieldDidBeginEditing:(UITextField *)textField
{
     if(textField == answer)
    {   
         CGPoint cPoint = textField.frame.origin;
         [scrollView setContentOffset:CGPointMake(0, cPoint.y - 100) animated:YES];
    }
}

注意：您必须根据视图更改cPoint.y-100值。

2012-12-03 17:35:26

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()

2019-07-06 21:16:30

请遵循以下步骤。

1）在.h文件中声明以下变量。

  {      
         CGFloat animatedDistance;
  }

2）在.m文件中声明以下常量。

  static const CGFloat KEYBOARD_ANIMATION_DURATION = 0.3;
  static const CGFloat MINIMUM_SCROLL_FRACTION = 0.2;
  static const CGFloat MAXIMUM_SCROLL_FRACTION = 0.8;
  static const CGFloat PORTRAIT_KEYBOARD_HEIGHT = 216;
  static const CGFloat LANDSCAPE_KEYBOARD_HEIGHT = 162;

3）使用UITextField代理向上/向下移动键盘。

  -(void) textFieldDidBeginEditing:(UITextField *)textField
  { 
         if(UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone)
         {
               CGRect textFieldRect = [self.view.window convertRect:textField.bounds fromView:textField];
               CGRect viewRect = [self.view.window convertRect:self.view.bounds fromView:self.view];

               CGFloat midline = textFieldRect.origin.y + 0.5 * textFieldRect.size.height;
               CGFloat numerator =
    midline - viewRect.origin.y
    - MINIMUM_SCROLL_FRACTION * viewRect.size.height;
               CGFloat denominator =
    (MAXIMUM_SCROLL_FRACTION - MINIMUM_SCROLL_FRACTION)
    * viewRect.size.height;
               CGFloat heightFraction = numerator / denominator;

               if (heightFraction < 0.0)
               {
                     heightFraction = 0.0;
               }
               else if (heightFraction > 1.0)
               {
                     heightFraction = 1.0;
               }

               UIInterfaceOrientation orientation =
    [[UIApplication sharedApplication] statusBarOrientation];
               if (orientation == UIInterfaceOrientationPortrait)
               {
                     animatedDistance = floor(PORTRAIT_KEYBOARD_HEIGHT * heightFraction);
               }
               else
               {
                     animatedDistance = floor(LANDSCAPE_KEYBOARD_HEIGHT * heightFraction);
               }

               CGRect viewFrame = self.view.frame;
               viewFrame.origin.y -= animatedDistance;

               [UIView beginAnimations:nil context:NULL];
               [UIView setAnimationBeginsFromCurrentState:YES];
               [UIView setAnimationDuration:KEYBOARD_ANIMATION_DURATION];

               [self.view setFrame:viewFrame];

               [UIView commitAnimations];
       }
  }

  -(void) textFieldDidEndEditing:(UITextField *)textField
  {
       if(UI_USER_INTERFACE_IDIOM()==UIUserInterfaceIdiomPhone)
       {
             CGRect viewFrame = self.view.frame;
             viewFrame.origin.y += animatedDistance;

             [UIView beginAnimations:nil context:NULL];
             [UIView setAnimationBeginsFromCurrentState:YES];
             [UIView setAnimationDuration:KEYBOARD_ANIMATION_DURATION];

             [self.view setFrame:viewFrame];

             [UIView commitAnimations];
       }
 }

2013-04-02 06:47:31

如果您现在的内容不适合iPhone屏幕，您只需要一个ScrollView。（如果您添加ScrollView作为组件的超级视图，只是为了在键盘启动时使TextField向上滚动，那么就不需要了。）防止TextFields被键盘覆盖的标准方法是在显示键盘时向上/向下移动视图。

下面是一些示例代码：

#define kOFFSET_FOR_KEYBOARD 80.0

-(void)keyboardWillShow {
    // Animate the current view out of the way
    if (self.view.frame.origin.y >= 0)
    {
        [self setViewMovedUp:YES];
    }
    else if (self.view.frame.origin.y < 0)
    {
        [self setViewMovedUp:NO];
    }
}

-(void)keyboardWillHide {
    if (self.view.frame.origin.y >= 0)
    {
        [self setViewMovedUp:YES];
    }
    else if (self.view.frame.origin.y < 0)
    {
        [self setViewMovedUp:NO];
    }
}

-(void)textFieldDidBeginEditing:(UITextField *)sender
{
    if ([sender isEqual:mailTf])
    {
        //move the main view, so that the keyboard does not hide it.
        if  (self.view.frame.origin.y >= 0)
        {
            [self setViewMovedUp:YES];
        }
    }
}

//method to move the view up/down whenever the keyboard is shown/dismissed
-(void)setViewMovedUp:(BOOL)movedUp
{
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:0.3]; // if you want to slide up the view

    CGRect rect = self.view.frame;
    if (movedUp)
    {
        // 1. move the view's origin up so that the text field that will be hidden come above the keyboard 
        // 2. increase the size of the view so that the area behind the keyboard is covered up.
        rect.origin.y -= kOFFSET_FOR_KEYBOARD;
        rect.size.height += kOFFSET_FOR_KEYBOARD;
    }
    else
    {
        // revert back to the normal state.
        rect.origin.y += kOFFSET_FOR_KEYBOARD;
        rect.size.height -= kOFFSET_FOR_KEYBOARD;
    }
    self.view.frame = rect;

    [UIView commitAnimations];
}


- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    // register for keyboard notifications
    [[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(keyboardWillShow)
                                             name:UIKeyboardWillShowNotification
                                           object:nil];

    [[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(keyboardWillHide)
                                             name:UIKeyboardWillHideNotification
                                           object:nil];
}

- (void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];
    // unregister for keyboard notifications while not visible.
    [[NSNotificationCenter defaultCenter] removeObserver:self
                                             name:UIKeyboardWillShowNotification
                                           object:nil];

    [[NSNotificationCenter defaultCenter] removeObserver:self
                                             name:UIKeyboardWillHideNotification
                                           object:nil];
}

2009-07-14 18:03:55

当键盘出现时，如何在开始编辑时使UITextField上移？

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