UITextField：键盘出现时移动视图-Java 学习之路

我目前正在开发一个带有单个视图的iPhone应用程序，它有多个UITextField用于输入 . 键盘显示时，它覆盖底部文本字段 . 所以我添加了相应的 textFieldDidBeginEditing: 方法，以便向上移动视图，效果很好：

- (void)textFieldDidBeginEditing:(UITextField *)textField {
    if ( ( textField != inputAmount ) && ( textField != inputAge ) ) {
        NSTimeInterval animationDuration = 0.300000011920929;
        CGRect frame = self.view.frame;
        frame.origin.y -= kOFFSET_FOR_KEYBOARD;
        frame.size.height += kOFFSET_FOR_KEYBOARD;
        [UIView beginAnimations:@"ResizeForKeyboard" context:nil];
        [UIView setAnimationDuration:animationDuration];
        self.view.frame = frame;
        [UIView commitAnimations];      
    }
}

如果消息源是键盘显示时可见的文本字段之一，则此方法检查，如果不是，则向上移动视图 .

我还添加了 textFieldDidEndEnditing: 方法，它再次向下移动视图（并根据更改的输入更新一些模型对象）：

- (void)textFieldDidEndEditing:(UITextField *)textField {
    if ( ( textField != inputMenge ) && ( textField != inputAlter ) ) {
        NSTimeInterval animationDuration = 0.300000011920929;
        CGRect frame = self.view.frame;
        frame.origin.y += kOFFSET_FOR_KEYBOARD;
        frame.size.height -= kOFFSET_FOR_KEYBOARD;
        [UIView beginAnimations:@"ResizeForKeyboard" context:nil];
        [UIView setAnimationDuration:animationDuration];
        self.view.frame = frame;
        [UIView commitAnimations];      
    }
    // Additional Code
}

但是，这个解决方案有一个简单的缺陷：当我完成编辑其中一个“隐藏”文本字段并触摸另一个文本字段时，键盘消失，视图向下移动，视图再次向上移动，键盘重新出现 .

是否有可能防止键盘在两个编辑（“隐藏”文本字段）之间消失和重新出现 - 这样当所选文本字段从键盘隐藏的文本字段变为不隐藏的字段时，视图才会移动）？

6 回答

此解决方案基于ComSubVie的解决方案 .

好处：

它支持设备旋转 - 适用于所有方向;
它不会对动画持续时间和曲线的值进行硬编码，而是从键盘通知中读取它们;
它利用 UIKeyboardWillShowNotification 而不是 UIKeyboardDidShowNotification 来同步键盘动画和自定义动作;
它不使用已弃用的 UIKeyboardBoundsUserInfoKey ;
由于按下国际键，它处理键盘调整大小;
通过取消注册键盘事件来修复内存泄漏;
所有键盘处理代码都封装在一个单独的类中 - KBKeyboardHandler ;
灵活性 - KBKeyboardHandler 课程可以轻松扩展/修改，以更好地满足特定需求;

限制：

适用于iOS 4及更高版本，需要进行少量修改才能支持旧版本;
适用于具有单个 UIWindow 的应用程序 . 如果使用多个UIWindows，则可能需要修改 retrieveFrameFromNotification: 方法 .

用法：

在项目中包含KBKeyboardHandler.h，KBKeyboardHandler.m和KBKeyboardHandlerDelegate.h . 在视图控制器中实现 KBKeyboardHandlerDelegate 协议 - 它由单个方法组成，当键盘显示，隐藏或其大小发生变化时，将调用该方法 . 实例化 KBKeyboardHandler 并设置其委托（通常为self） . 请参见下面的示例 MyViewController .

KBKeyboardHandler.h ：

#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>

@protocol KBKeyboardHandlerDelegate;

@interface KBKeyboardHandler : NSObject

- (id)init;

// Put 'weak' instead of 'assign' if you use ARC
@property(nonatomic, assign) id<KBKeyboardHandlerDelegate> delegate; 
@property(nonatomic) CGRect frame;

@end

KBKeyboardHandler.m ：

#import "KBKeyboardHandler.h"
#import "KBKeyboardHandlerDelegate.h"

@implementation KBKeyboardHandler

- (id)init
{
    self = [super init];
    if (self)
    {
        [[NSNotificationCenter defaultCenter] addObserver:self
                                                 selector:@selector(keyboardWillShow:)
                                                     name:UIKeyboardWillShowNotification
                                                   object:nil];

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

    return self;
}

- (void)dealloc
{
    [[NSNotificationCenter defaultCenter] removeObserver:self];
    [super dealloc];
}

@synthesize delegate;
@synthesize frame;

- (void)keyboardWillShow:(NSNotification *)notification
{
    CGRect oldFrame = self.frame;    
    [self retrieveFrameFromNotification:notification];

    if (oldFrame.size.height != self.frame.size.height)
    {
        CGSize delta = CGSizeMake(self.frame.size.width - oldFrame.size.width,
                                  self.frame.size.height - oldFrame.size.height);
        if (self.delegate)
            [self notifySizeChanged:delta notification:notification];
    }
}

- (void)keyboardWillHide:(NSNotification *)notification
{
    if (self.frame.size.height > 0.0)
    {
        [self retrieveFrameFromNotification:notification];
        CGSize delta = CGSizeMake(-self.frame.size.width, -self.frame.size.height);

        if (self.delegate)
            [self notifySizeChanged:delta notification:notification];
    }

    self.frame = CGRectZero;
}

- (void)retrieveFrameFromNotification:(NSNotification *)notification
{
    CGRect keyboardRect;
    [[[notification userInfo] objectForKey:UIKeyboardFrameEndUserInfoKey] getValue:&keyboardRect];
    self.frame = [[UIApplication sharedApplication].keyWindow.rootViewController.view convertRect:keyboardRect fromView:nil];
}

- (void)notifySizeChanged:(CGSize)delta notification:(NSNotification *)notification
{
    NSDictionary *info = [notification userInfo];

    UIViewAnimationOptions curve;
    [[info objectForKey:UIKeyboardAnimationCurveUserInfoKey] getValue:&curve];

    NSTimeInterval duration;
    [[info objectForKey:UIKeyboardAnimationDurationUserInfoKey] getValue:&duration];

    void (^action)(void) = ^{
        [self.delegate keyboardSizeChanged:delta];
    };

    [UIView animateWithDuration:duration
                          delay:0.0
                        options:curve
                     animations:action
                     completion:nil];    
}

@end

KBKeyboardHandlerDelegate.h ：

@protocol KBKeyboardHandlerDelegate

- (void)keyboardSizeChanged:(CGSize)delta;

@end

示例 MyViewController.h ：

@interface MyViewController : UIViewController<KBKeyboardHandlerDelegate>
...
@end

示例 MyViewController.m ：

@implementation MyViewController
{
    KBKeyboardHandler *keyboard;
}

- (void)dealloc
{
    keyboard.delegate = nil;
    [keyboard release];
    [super dealloc];
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    keyboard = [[KBKeyboardHandler alloc] init];
    keyboard.delegate = self;
}

- (void)viewDidUnload
{
    [super viewDidUnload];
    keyboard.delegate = nil;
    [keyboard release];
    keyboard = nil;
}

- (void)keyboardSizeChanged:(CGSize)delta
{
    // Resize / reposition your views here. All actions performed here 
    // will appear animated.
    // delta is the difference between the previous size of the keyboard 
    // and the new one.
    // For instance when the keyboard is shown, 
    // delta may has width=768, height=264,
    // when the keyboard is hidden: width=-768, height=-264.
    // Use keyboard.frame.size to get the real keyboard size.

    // Sample:
    CGRect frame = self.view.frame;
    frame.size.height -= delta.height;
    self.view.frame = frame;
}

更新：修复了iOS 7警告，感谢@weienv .

回复于 2024-04-26T11:55:32+08:00

我刚刚解决了这个问题 . 该解决方案是 UIKeyboardDidShowNotification 和 UIKeyboardDidHideNotification 观察者与上述 textFieldDidBeginEditing: 和 textFieldDidEndEditing: 方法的组合 .

您需要三个附加变量，一个用于存储当前选定的UITextField（我已命名为activeField），一个用于指示当前视图是否已移动，另一个用于指示是否显示键盘 .

这就是两个 UITextField 委托方法现在的样子：

- (void)textFieldDidBeginEditing:(UITextField *)textField {
    activeField = textField;
}

- (void)textFieldDidEndEditing:(UITextField *)textField {
    activeField = nil;
    // Additional Code
}

加载视图时，将创建以下两个观察者：

- (void)viewDidLoad {
    // Additional Code
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWasShown:)
                                                 name:UIKeyboardDidShowNotification
                                               object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWasHidden:)
                                                 name:UIKeyboardDidHideNotification
                                               object:nil];
}

相应的方法实现如下：

- (void)keyboardWasShown:(NSNotification *)aNotification {
    if ( keyboardShown )
        return;

    if ( ( activeField != inputAmount ) && ( activeField != inputAge ) ) {
        NSDictionary *info = [aNotification userInfo];
        NSValue *aValue = [info objectForKey:UIKeyboardBoundsUserInfoKey];
        CGSize keyboardSize = [aValue CGRectValue].size;

        NSTimeInterval animationDuration = 0.300000011920929;
        CGRect frame = self.view.frame;
        frame.origin.y -= keyboardSize.height-44;
        frame.size.height += keyboardSize.height-44;
        [UIView beginAnimations:@"ResizeForKeyboard" context:nil];
        [UIView setAnimationDuration:animationDuration];
        self.view.frame = frame;
        [UIView commitAnimations];

        viewMoved = YES;
    }

    keyboardShown = YES;
}

- (void)keyboardWasHidden:(NSNotification *)aNotification {
    if ( viewMoved ) {
        NSDictionary *info = [aNotification userInfo];
        NSValue *aValue = [info objectForKey:UIKeyboardBoundsUserInfoKey];
        CGSize keyboardSize = [aValue CGRectValue].size;

        NSTimeInterval animationDuration = 0.300000011920929;
        CGRect frame = self.view.frame;
        frame.origin.y += keyboardSize.height-44;
        frame.size.height -= keyboardSize.height-44;
        [UIView beginAnimations:@"ResizeForKeyboard" context:nil];
        [UIView setAnimationDuration:animationDuration];
        self.view.frame = frame;
        [UIView commitAnimations];

        viewMoved = NO;
    }

    keyboardShown = NO;
}

此代码现在按预期工作 . 键盘仅在按下“完成”按钮时被解除，否则它将保持可见状态并且视图不会移动 .

另外需要注意的是，我认为可以通过询问 NSNotification 对象来动态获取 animationDuration ，因为我已经使用了类似的解决方案，但是没有让它工作（它现在就是这样） .

回复于 2024-04-26T11:55:32+08:00

此视图控制器必须是 UITextView Delegate，您必须在 viewdidload 中设置 self.textview.delegate = self

-(void) textViewDidBeginEditing:(UITextView *)textView
    {
        NSLog(@"%f",self.view.frame.origin.y);
        [UIView beginAnimations:nil context:NULL];
        [UIView setAnimationDuration:0.25f];
        CGRect frame = self.view.frame;
        frame.origin.y =frame.origin.y -204;
        [self.view setFrame:frame];
        [UIView commitAnimations];
    }

-(void) textViewDidEndEditing:(UITextView *)textView
{
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:0.25f];
    CGRect frame = self.view.frame;
    frame.origin.y = frame.origin.y + 204;
    [self.view setFrame:frame];
    [UIView commitAnimations];
}

回复于 2024-04-26T11:55:32+08:00

我得到你的问题只是简单的事情只是给UIScrollview的出口 . 为视图中的每个文本字段设置唯一的Tag属性 .

-(void)textFieldDidBeginEditing:(UITextField *)textField
    {   
        switch (textField.tag)
        {
            case 2:    //can be your textfiled tag
              { CGPoint scrollPoint = CGPointMake(0, yourtextfield.frame.origin.y-150); 
                                           //set figure y-150 as per your comfirt
                  [scrollview setContentOffset:scrollPoint animated:YES]; 
             }break;

              case 3:   
              { CGPoint scrollPoint = CGPointMake(0, yourtextfield.frame.origin.y-180); 
                                           //set figure y-180 as per your comfirt
                  [scrollview setContentOffset:scrollPoint animated:YES]; 
             }break;

             ...

         }
    }

    -(void)textFieldDidEndEditing:(UITextField *)textField{

        if(textField.tag==3){
            [scrollview setContentOffset:CGPointZero animated:YES];
                }
         //set the last textfield when you want to disappear keyboard.
    }

回复于 2024-04-26T11:55:32+08:00

Write below code in your view controller. tbl is your table view. 

-(void)viewWillAppear:(BOOL)animated{


    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillChangeFrame:) name:UIKeyboardWillChangeFrameNotification object:nil];
    [[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
{
    [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillChangeFrameNotification object:nil];
    [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillShowNotification object:nil];
    [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillHideNotification object:nil];
}



#pragma mark - Keyboard Methods
-(void)keyboardWillShow:(NSNotification *)notification
{
//    375 × 667  ( 750 × 1334 ) iPhone 6
    //414 × 736
    CGRect keyboardRect = [[[notification userInfo] valueForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];
    int H = [[UIScreen mainScreen] bounds].size.height - 64- 20 -keyboardRect.size.height;
    [UIView animateWithDuration:0.5 animations:^{
        tbl.contentInset = UIEdgeInsetsMake(tbl.contentInset.top, tbl.contentInset.left, H, tbl.contentInset.right);
    }];
}

-(void)keyboardWillChangeFrame:(NSNotification *)notification
{
    CGRect keyboardRect = [[[notification userInfo] valueForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];
//    int H = IS_IPHONE_5?504-keyboardRect.size.height:416-keyboardRect.size.height;
     int H = [[UIScreen mainScreen] bounds].size.height - 64- 20  -keyboardRect.size.height;
    [UIView animateWithDuration:0.5 animations:^{
        //        scroll.frame = rect;
        tbl.contentInset = UIEdgeInsetsMake(tbl.contentInset.top, tbl.contentInset.left, H, tbl.contentInset.right);
    }];
}


-(void)keyboardWillHide:(NSNotification *)notification
{

    [UIView animateWithDuration:0.3 animations:^{
        //        scroll.frame = rect;
        tbl.contentInset = UIEdgeInsetsMake(tbl.contentInset.top, tbl.contentInset.left, 0, tbl.contentInset.right);
    }];
}

回复于 2024-04-26T11:55:32+08:00

非常简单的解决方案，适用于所有屏幕尺寸

首先，您必须将UITextFields嵌入到UIScrollView中 . 在我的例子中，我有几个UITextFields和一个UITextView .

enter image description here

然后你必须从UITextFieldDelegate，UITextViewDelegate继承 .

class SettingsVC: UIViewController, UITextFieldDelegate, UITextViewDelegate

将textfield和textview的委托分配给self .

fullNameTextField.delegate = self usernameTextField.delegate = self websiteTextField.delegate = self profileDescription.delegate = self

然后使用此代码：

var editingTextInput: UIView!


override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)

    NotificationCenter.default.addObserver(self,
                                           selector: #selector(self.keyboardShown(notification:)),
                                           name: NSNotification.Name.UIKeyboardDidShow,
                                           object: nil)
    

  }
  
    override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)
    
    NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardDidShow, object: nil)
  }
  
  func keyboardShown(notification: NSNotification) {
    
    if let infoKey  = notification.userInfo?[UIKeyboardFrameEndUserInfoKey],
      let rawFrame = (infoKey as AnyObject).cgRectValue {
      
      let keyboardFrame = view.convert(rawFrame, to: view)
      let editingTextInputFrame = self.editingTextInput.convert(self.editingTextInput.frame, to: view)

      
      if editingTextInputFrame.maxY > keyboardFrame.minY{
        
        let diff = keyboardFrame.minY - editingTextInputFrame.maxY
        containerScrollView.setContentOffset(CGPoint(x: 0, y: -diff), animated: true)
        
      }
    }
  }
  
  func textFieldDidBeginEditing(_ textField: UITextField) {
    self.editingTextInput = textField
  }
  
  func textViewDidBeginEditing(_ textView: UITextView) {
    self.editingTextInput = textView
  }
  
  func textFieldDidEndEditing(_ textField: UITextField) {
    containerScrollView.setContentOffset(CGPoint.zero, animated: true)
  }
  
  func textViewDidEndEditing(_ textView: UITextView) {
    containerScrollView.setContentOffset(CGPoint.zero, animated: true)
  }

简而言之，您订阅了UIKeyboardDidShow通知 . 当您点击textField或显示textView键盘时，您可以轻触键盘的输入元素的框架和框架 . 将它们转换为viewController的坐标系并将输入元素的最低点与键盘的最高点进行比较 . 如果element的下半部分低于键盘的最高值，则将containerScrollView的偏移量设置为它们之间的差值 .

if editingTextInputFrame.maxY > keyboardFrame.minY{
            
            let diff = keyboardFrame.minY - editingTextInputFrame.maxY
            containerScrollView.setContentOffset(CGPoint(x: 0, y: -diff), animated: true)
            
          }

res1

res2

回复于 2024-04-26T11:55:32+08:00

UITextField：键盘出现时移动视图

6 回答

非常简单的解决方案，适用于所有屏幕尺寸

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