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

我发现这是最好的解决方案,请遵循以下代码:

将以下内容附加到垂直空间-底部布局指南-文本字段约束。

@property (weak, nonatomic) IBOutlet NSLayoutConstraint *textViewBottomConst;

第二,为键盘通知添加观察员。

- (void)observeKeyboard {
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];
}

将此添加到您的视图DidLoad

[self observeKeyboard]; 

最后,处理键盘更改的方法。

- (void)keyboardWillShow:(NSNotification *)notification {
//THIS WILL MAKE SURE KEYBOARD DOESNT JUMP WHEN OPENING QUICKTYPE/EMOJI OR OTHER KEYBOARDS.
kbHeight = 0;
height = 0;
self.textViewBottomConst.constant = height;
self.btnViewBottomConst.constant = height;

    NSDictionary *info = [notification userInfo];
    NSValue *kbFrame = [info objectForKey:UIKeyboardFrameEndUserInfoKey];

    NSTimeInterval animationDuration = [[info objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
    CGRect keyboardFrame = [kbFrame CGRectValue];

    CGRect finalKeyboardFrame = [self.view convertRect:keyboardFrame fromView:self.view.window];

    int kbHeight = finalKeyboardFrame.size.height;

    int height = kbHeight + self.textViewBottomConst.constant;

    self.textViewBottomConst.constant = height;

    [UIView animateWithDuration:animationDuration animations:^{
        [self.view layoutIfNeeded];
    }];
}

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

    NSTimeInterval animationDuration = [[info objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];

    self.textViewBottomConst.constant = 10;

    [UIView animateWithDuration:animationDuration animations:^{
        [self.view layoutIfNeeded];
    }];
}

其他回答

这是独立于设备的偏移计算。获取键盘和文本字段之间的重叠高度:

func keyboardShown(notification: NSNotification) {
    let info  = notification.userInfo!
    let value: AnyObject = info[UIKeyboardFrameEndUserInfoKey]!

    let rawFrame = value.CGRectValue
    let keyboardFrame = view.convertRect(rawFrame, fromView: nil)

    let screenHeight = UIScreen.mainScreen().bounds.size.height;
    let Ylimit = screenHeight - keyboardFrame.size.height
    let textboxOriginInSuperview:CGPoint = self.view.convertPoint(CGPointZero, fromCoordinateSpace: lastTextField!)

    self.keyboardHeight = (textboxOriginInSuperview.y+self.lastTextField!.frame.size.height) - Ylimit

    if(self.keyboardHeight>0){
        self.animateViewMoving(true, moveValue: keyboardHeight!)
    }else{
        keyboardHeight=0
    }
}

keyBoardHeight是偏移量。

我把所有的东西都放在一节课上。加载视图控制器时,只需调用以下代码行:

- (void)viewDidLoad {
    [super viewDidLoad];
    KeyboardInsetScrollView *injectView = [[KeyboardInsetScrollView alloc] init];
    [injectView injectToView:self.view withRootView:self.view];
}

以下是示例项目的链接:https://github.com/caohuuloc/KeyboardInsetScrollView

如果文本字段未完全或部分隐藏,则我们不应更改任何内容。我们应该计算隐藏的精确相交区域(键盘的框架和文本字段的框架),然后我们应该更改视图的框架。这里我给出了一个完整的例子。声明3个变量

#定义衬垫10@接口PKViewController()@属性(非原子,赋值)CGRect-originalViewFrame//原始视图的框架@属性(非原子,强)UITextField*activeTextField;//当前文本字段@属性(非原子,赋值)CGRect keyBoardRect;//安全板覆盖面积@完

存储原始帧

- (void)viewDidLoad {
    [super viewDidLoad];
    _originalViewFrame = self.view.frame;
}

将视图控制器添加为键盘通知的观察者

- (void)viewWillAppear:(BOOL)animated{
    [super viewWillAppear:animated];
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWasShown:)
                                                 name:UIKeyboardDidShowNotification
                                               object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWillHide:)
                                                 name:UIKeyboardWillHideNotification
                                               object:nil];
}

移除观察者

- (void)viewWillDisappear:(BOOL)animated{
    [super viewWillDisappear:animated];
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}

当键盘出现时存储键盘覆盖的区域,当键盘消失时将其设置为CGRectZero

- (void)keyboardWasShown:(NSNotification *)notification{
    CGSize keyboardSize = [[[notification userInfo] objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;
    _keyBoardRect = CGRectMake(0, _originalViewFrame.size.height - keyboardSize.height, keyboardSize.width, keyboardSize.height);
    [self moveTextFieldUP];

}
- (void) keyboardWillHide:(NSNotification *)notification{
    _keyBoardRect = CGRectZero;
    [self setDefaultFrame];
}

存储活动文本字段

- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField {
    _activeTextField = textField;
//When keyboard is already present but the textfield is hidden. Case:When return key of  keyboard makes the next textfield as first responder
    if (!CGRectIsEmpty(_keyBoardRect)) { 
        [self moveTextFieldUP];
    }
    return YES;
}
- (BOOL)textFieldShouldReturn:(UITextField *)textField{
    [textField resignFirstResponder];
    return YES;
}

现在我们应该改变视图的框架

- (void)moveTextFieldUP{
    CGRect virtualTextFieldRect = CGRectMake(0, self.view.frame.origin.y, _activeTextField.frame.size.width, _activeTextField.frame.origin.y+_activeTextField.frame.size.height);
    if (CGRectIntersectsRect(_keyBoardRect, virtualTextFieldRect)) {
        CGRect intersectRect = CGRectIntersection(_keyBoardRect, virtualTextFieldRect);
        CGFloat newY = _originalViewFrame.origin.y - intersectRect.size.height;
        CGFloat newHeight = _originalViewFrame.size.height + intersectRect.size.height;
        CGRect newFrame = CGRectMake(0, newY-PADDING, _originalViewFrame.size.width, newHeight+PADDING);
        [UIView animateWithDuration:0.3 animations:^{
            [self.view setFrame:newFrame];
        }];

        NSLog(@"Intersect");
    }
}
- (void)setDefaultFrame {
    [UIView animateWithDuration:0.3 animations:^{
        [self.view setFrame:_originalViewFrame];
    }];
}

虽然这条线索已经得到了足够的答案,但我想建议一种更简单但更通用的方法,就像苹果一样,将键盘的高度考虑在内,这在我们使用键盘顶部的自定义工具栏时非常有用。尽管苹果在这方面的做法没有什么问题。

这是我的方法(略微修改了苹果的方法)-

// Called when the UIKeyboardDidShowNotification is sent.
- (void)keyboardWasShown:(NSNotification*)aNotification
{
    NSDictionary* info = [aNotification userInfo];
    CGSize kbSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;

    UIEdgeInsets contentInsets = UIEdgeInsetsMake(0.0, 0.0, kbSize.height, 0.0);
    self.scrollView.contentInset = contentInsets;
    self.scrollView.scrollIndicatorInsets = contentInsets;
}

// Called when the UIKeyboardWillHideNotification is sent
- (void)keyboardWillBeHidden:(NSNotification*)aNotification
{
    UIEdgeInsets contentInsets = UIEdgeInsetsZero;
    self.scrollView.contentInset = contentInsets;
    self.scrollView.scrollIndicatorInsets = contentInsets;
}

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];
       }
 }