防止键盘重叠 UIButton / UITextField

Posted 2023-03-11

【中文标题】防止键盘重叠 UIButton / UITextField

【英文标题】：Prevent keyboard from overlapping UIButton / UITextField

【发布时间】：2014-03-13 06:02:07

【问题描述】：

我一直在通过以下网址阅读 Apple 提供的文本编程指南：

https://developer.apple.com/library/ios/documentation/StringsTextFonts/Conceptual/TextAndWebiPhoneOS/KeyboardManagement/KeyboardManagement.html

我试图防止按钮和文本字段被键盘重叠。

当我按照指南的说明粘贴清单 5-1（如下所列）中的代码时，我收到如下错误：

" Use of unidentified identifier 'scrollView'; Did you mean 'UIScrollView' ? "

和

" Property 'contentsInset' not found in 'scrollView' "



// Call this method somewhere in your view controller setup code.
- (void)registerForKeyboardNotifications

    [[NSNotificationCenter defaultCenter] addObserver:self
            selector:@selector(keyboardWasShown:)
            name:UIKeyboardDidShowNotification object:nil];

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



// 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);
    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.
    CGRect aRect = self.view.frame;
    aRect.size.height -= kbSize.height;
    if (!CGRectContainsPoint(aRect, activeField.frame.origin) ) 
        [self.scrollView scrollRectToVisible:activeField.frame animated:YES];
    


// Called when the UIKeyboardWillHideNotification is sent
- (void)keyboardWillBeHidden:(NSNotification*)aNotification

    UIEdgeInsets contentInsets = UIEdgeInsetsZero;
    scrollView.contentInset = contentInsets;
    scrollView.scrollIndicatorInsets = contentInsets;

【问题讨论】：

你真的使用滚动视图吗？

是的，我已经将 UIViewController 的内容（两个文本字段和一个按钮）嵌入到滚动视图 @GenieWanted

你的 UIScrollView 叫什么名字？您需要指定它来代替 scrollView。

我如何检查这个？ @GenieWanted

您必须在 .h 文件中声明了 UIScrollView。对吗？

【参考方案1】：

试试这个代码会解决你的问题，用TextField替换TextView

-(void)textViewDidBeginEditing:(UITextView *)textView

    [self animateTextFild:textView up:YES];


-(void)textViewDidEndEditing:(UITextView *)textView

    [self animateTextFild:textView up:NO];
    [textView resignFirstResponder];


-(void) animateTextFild:(UITextView *)textField up:(BOOL)up

    int animatedDistance;

    int moveUpValue = textField.frame.origin.y+ textField.frame.size.height;

    UIInterfaceOrientation orientation =
    [[UIApplication sharedApplication] statusBarOrientation];

    if (orientation == UIInterfaceOrientationPortrait ||
        orientation == UIInterfaceOrientationPortraitUpsideDown)
    

        animatedDistance = 216-(730-moveUpValue);
    
    else
    
        animatedDistance = 162-(520-moveUpValue);
    

    if(animatedDistance>0)
    
        const int movementDistance = animatedDistance;

        const float movementDuration = 0.3f;

        int movement = (up ? -movementDistance : movementDistance);

        [UIView beginAnimations: nil context: nil];

        [UIView setAnimationBeginsFromCurrentState: YES];

        [UIView setAnimationDuration: movementDuration];

        myView.frame = CGRectOffset(ViewEdit.frame, 0, movement);

        [UIView commitAnimations];
    

【参考方案2】：

下面的方法会对你有所帮助。

在您的 .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;

并添加以下代码

 - (void)textFieldDidBeginEditing:(UITextField *)textField
    
        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 ||
        orientation == UIInterfaceOrientationPortraitUpsideDown)
    
        animatedDistance = floor(PORTRAIT_KEYBOARD_HEIGHT * heightFraction);
    
    else
    
        animatedDistance = floor(LANDSCAPE_KEYBOARD_HEIGHT * heightFraction);
    

    CGRect viewFrame = self.scrollView.frame;
    viewFrame.origin.y -= animatedDistance;
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationBeginsFromCurrentState:YES];
    [UIView setAnimationDuration:KEYBOARD_ANIMATION_DURATION];

    [self.scrollView setFrame:viewFrame];

    [UIView commitAnimations];
    for (id navigBar in [self.view subviews])
    
        if ([navigBar isKindOfClass:[UINavigationBar class]])
        
            [self.view bringSubviewToFront:navigBar];
        
    



- (void)textFieldDidEndEditing:(UITextField *)textField

    CGRect viewFrame = self.scrollView.frame;
    viewFrame.origin.y += animatedDistance;

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

    [self.scrollView setFrame:viewFrame];

    [UIView commitAnimations];
    for (id navigBar in [self.view subviews]) 

        if ([navigBar isKindOfClass:[UINavigationBar class]])
        
            [self.view bringSubviewToFront:navigBar];
        
    

【参考方案3】：

我找到的最合适的解决方案：COCOAWITHLOVE

// Keyboard correction method.
CGFloat animatedDistance;
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;

- (void)textFieldDidBeginEditing:(UITextField *)textField

    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 ||
        orientation == UIInterfaceOrientationPortraitUpsideDown)
    
        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

    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];


- (BOOL)textFieldShouldReturn:(UITextField *)textField

    [textField resignFirstResponder];
    return YES;