经过大量的试验和错误,我放弃了,并提出了这个问题。我见过很多人有类似的问题,但不能得到所有的答案工作正确。

我有一个由自定义单元格组成的UITableView。单元格由相邻的5个文本字段组成(有点像网格)。

当我试图滚动和编辑UITableView底部的单元格时,我不能设法让我的单元格正确地定位在键盘上方。

我看到过很多关于改变视图大小的回答……但到目前为止,没有一种效果很好。

谁能用一个具体的代码示例来阐明这样做的“正确”方式?


当前回答

Swift最简单的解决方案:

override func viewDidLoad() {
    super.viewDidLoad()
    
    searchBar?.becomeFirstResponder()
    NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(MyViewController.keyboardWillShow(_:)), name: UIKeyboardDidShowNotification, object: nil)
    NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(MyViewController.keyboardWillHide(_:)), name: UIKeyboardDidHideNotification, object: nil)
}

deinit {
    NSNotificationCenter.defaultCenter().removeObserver(self)
}

func keyboardWillShow(notification: NSNotification) {
    if let userInfo = notification.userInfo {
        if let keyboardHeight = userInfo[UIKeyboardFrameEndUserInfoKey]?.CGRectValue.size.height {
            tableView.contentInset = UIEdgeInsetsMake(0, 0, keyboardHeight, 0)
        }
    }
}

func keyboardWillHide(notification: NSNotification) {
    UIView.animateWithDuration(0.2, animations: { self.table_create_issue.contentInset = UIEdgeInsetsMake(0, 0, 0, 0) })
    // For some reason adding inset in keyboardWillShow is animated by itself but removing is not, that's why we have to use animateWithDuration here
    }

Swift 4.2或更高版本

override func viewDidLoad() {
    super.viewDidLoad()
    searchBar?.becomeFirstResponder()
    NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillShow), name: UIResponder.keyboardDidShowNotification, object: nil)
    NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillHide), name: UIResponder.keyboardDidHideNotification, object: nil)
}

deinit {
    NotificationCenter.default.removeObserver(self)
}

 @objc func keyboardWillShow(notification: NSNotification) {
    if let userInfo = notification.userInfo {
            let keyboardHeight = (userInfo[UIResponder.keyboardFrameEndUserInfoKey] as AnyObject).cgRectValue.size.height
            accountSettingsTableView.contentInset = UIEdgeInsets(top: 0, left: 0, bottom: keyboardHeight, right: 0)
        
    }
}
@objc func keyboardWillHide(notification: NSNotification) {
    UIView.animate(withDuration: 0.2, animations: { self.accountSettingsTableView.contentInset = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0) })}
}

其他回答

以下是我的解决方案,灵感来自iOS7日历应用程序的“事件编辑”屏幕。

该解决方案的关键之一是当用户滚动表格时键盘被取消。

实现:

1)添加属性,将存储选定的文本字段:

@property (strong) UITextField *currentTextField;

和BOOL变量,我们将使用它来检查当用户滚动表时是否需要隐藏键盘。

BOOL hideKeyboardOnScroll;

2)处理UITextField委托回调:

#pragma mark - UITextFieldDelegate

- (void) textFieldDidBeginEditing: (UITextField *) textField {
    self.currentTextField = textField;
}

- (void) textFieldDidEndEditing: (UITextField *) textField {
    self.currentTextField = nil;
}

- (BOOL) textFieldShouldReturn: (UITextField *) textField {
   [textField resignFirstResponder];

    CGPoint newContentOffset = CGPointZero;
    if (tableView.contentSize.height > tableView.frame.size.height) {
        newContentOffset.y = MIN(tableView.contentOffset.y, tableView.contentSize.height - tableView.frame.size.height);
    }
    [tableView setContentOffset: newContentOffset animated: YES];

    return YES;
}

3)处理UIScrollViewDelegate方法来检查用户滚动视图。

#pragma mark - UIScrollViewDelegate

- (void) scrollViewDidScroll: (UIScrollView *) scrollView {
    if (hideKeyboardOnScroll == YES) {
        [self.currentTextField resignFirstResponder];
    }
}

4)在视图控制器的[viewWillAppear]方法中订阅键盘通知,并在[viewWillDisappear]方法中取消订阅。

- (void) viewWillAppear: (BOOL) animated {
    [super viewWillAppear: animated];

    [ [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];

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

5)处理键盘通知:

- (void) keyboardWillShow: (NSNotification *) notification {
    CGRect keyboardFrame = [ [ [notification userInfo] objectForKey: UIKeyboardFrameBeginUserInfoKey] CGRectValue];

    // Find cell with textfield.
    CGRect textFieldFrame = [tableView convertRect: self.currentTextField.frame fromView: self.currentTextField];
    NSIndexPath *indexPath = [tableView indexPathForRowAtPoint: textFieldFrame.origin];
    UITableViewCell *cell = [tableView cellForRowAtIndexPath: indexPath];
    //

    // Shrink tableView size.
    CGRect tableViewFrame = tableView.frame;
    tableView.frame = CGRectMake(tableView.frame.origin.x, tableView.frame.origin.y, tableView.frame.size.width,
                             self.view.frame.size.height - tableView.frame.origin.y - keyboardFrame.size.height);
    //

    // Check if cell is visible in shrinked table size.
    BOOL cellIsFullyVisible = YES;
    if ( cell.frame.origin.y < tableView.contentOffset.y ||
        (cell.frame.origin.y + cell.frame.size.height) > (tableView.contentOffset.y + tableView.frame.size.height) ) {
        cellIsFullyVisible = NO;
    }
    //

    // If cell is not fully visible when scroll table to show cell;
    if (cellIsFullyVisible == NO) {
        CGPoint contentOffset = CGPointMake(tableView.contentOffset.x, CGRectGetMaxY(cell.frame) - tableView.frame.size.height);
        if (cell.frame.origin.y < tableView.contentOffset.y) {
            contentOffset.y = cell.frame.origin.y;
        }
        contentOffset.y = MAX(0, contentOffset.y);

        // For some reason [setContentOffset] is called without delay then
        // this code may not work for some cells. That why we call it with brief delay.
        dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.1 * NSEC_PER_SEC));
        dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
            [UIView animateWithDuration: 0.5 animations:^{
                [tableView setContentOffset: contentOffset animated: NO];
            } completion: ^(BOOL finished) {
                hideKeyboardOnScroll = YES;
            }];
        });
    } else {
        hideKeyboardOnScroll = YES;
    }
    //

    // Finally restore original table frame.
    tableView.frame = tableViewFrame;
    //
}

- (void) keyboardWillHide: (NSNotification *) notification {
    [super keyboardWillHide: notification];

    hideKeyboardOnScroll = NO;
}

我认为没有“正确”的方法来做这件事。您必须为您的用例选择最合适的解决方案。 在我的iPad App中,我有一个UIViewController,它以UIModalPresentationFormSheet的形式呈现,由一个UITableView组成。这个表格每个单元格包含两个UITextFields。 只是调用scrollToRowAtIndexPath:atScrollPosition:animated:在textFieldDidBeginEditing:方法不为我工作。因此,我创建了一个tableFooterView:

- (void)viewDidLoad
{
    [super viewDidLoad];

    m_footerView = [[UIView alloc] initWithFrame:CGRectMake(0.0f, 0.0f, m_tableView.frame.size.width, 300.0f)];
    [m_footerView setBackgroundColor:[UIColor clearColor]];
    [m_tableView setTableFooterView:m_footerView];
    [m_footerView release];
}

这个想法是键盘隐藏tableFooterView而不是UITextFields。tableFooterView必须足够高。之后,你可以在textFieldDidBeginEditing:方法中使用scrollToRowAtIndexPath:atScrollPosition:animated:。

我认为也可以通过添加键盘通知的观察者来动态地显示和隐藏tableFooterView,但我还没有尝试过:

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];

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

- (void)keyboardWillShow:(NSNotification *)notification 
{
     [m_tableView setTableFooterView:m_footerView];
}

- (void)keyboardWillHide:(NSNotification *)notification 
{
     [m_tableView setTableFooterView:nil];
}

- (void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];

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

我刚刚解决了这样一个问题,我参考了大量的解决方案通过谷歌和堆栈溢出。

首先,请确保你已经为UIScrollView设置了IBOutlet, 那么请仔细看看Apple Doc: Keyboard Management。 最后,如果你可以滚动背景,但键盘仍然覆盖文本字段,请看看这段代码:

// If active text field is hidden by keyboard, scroll it so it's visible
// Your application might not need or want this behavior.
CGRect aRect = self.view.frame;
aRect.size.height -= kbSize.height;

if (aRect.size.height < activeField.frame.origin.y+activeField.frame.size.height) {

    CGPoint scrollPoint = CGPointMake(0.0, activeField.frame.origin.y+activeField.frame.size.height-aRect.size.height);

    [scrollView setContentOffset:scrollPoint animated:YES];

这款游戏与苹果游戏的主要区别在于if条件。我认为apple计算滚动距离和键盘是否覆盖文本字段的条件不准确,所以我做了如上修改。

如果有用请告诉我

如果你的UITableView是由UITableViewController的子类管理的,而不是UITableView,并且文本字段委托是UITableViewController,它应该自动管理所有的滚动——所有这些其他注释在实践中是很难实现的。

有关一个好例子,请参阅apple示例代码项目:TaggedLocations。

你可以看到它自动滚动,但似乎没有任何代码做到这一点。该项目还具有自定义表视图单元格,因此,如果使用它作为指南构建应用程序,应该会得到预期的结果。

结合并填写几个答案(特别是Ortwin Gentz,用户98013)和另一篇文章中的空白,这将适用于iPad上的SDK 4.3的纵向或横向模式:

@implementation UIView (FindFirstResponder)
- (UIResponder *)findFirstResponder
{
  if (self.isFirstResponder) {        
    return self;     
  }

  for (UIView *subView in self.subviews) {
    UIResponder *firstResponder = [subView findFirstResponder];
    if (firstResponder != nil) {
      return firstResponder;
    }
  }

  return nil;
}
@end

@implementation MyViewController

- (UIResponder *)currentFirstResponder {
  return [self.view findFirstResponder];
}

- (IBAction)editingEnded:sender {
  [sender resignFirstResponder];
}

- (BOOL)textFieldShouldReturn:(UITextField *)textField {
  [textField resignFirstResponder];
  return NO;
}

- (void)textFieldDidBeginEditing:(UITextField *)textField {
  UITableViewCell *cell = (UITableViewCell*) [[textField superview] superview];
  [_tableView scrollToRowAtIndexPath:[_tableView indexPathForCell:cell] atScrollPosition:UITableViewScrollPositionTop animated:YES];
}

- (void)keyboardWillShow:(NSNotification*)notification {
  if ([self currentFirstResponder] != nil) {
    NSDictionary* userInfo = [notification userInfo];

    // we don't use SDK constants here to be universally compatible with all SDKs ≥ 3.0
    NSValue* keyboardFrameValue = [userInfo objectForKey:@"UIKeyboardBoundsUserInfoKey"];
    if (!keyboardFrameValue) {
      keyboardFrameValue = [userInfo objectForKey:@"UIKeyboardFrameEndUserInfoKey"];
    }

    // Reduce the tableView height by the part of the keyboard that actually covers the tableView
    CGRect windowRect = [[UIApplication sharedApplication] keyWindow].bounds;
    CGRect viewRectAbsolute = [_tableView convertRect:_tableView.bounds toView:[[UIApplication sharedApplication] keyWindow]];
    CGRect frame = _tableView.frame;
    if (UIInterfaceOrientationLandscapeLeft == self.interfaceOrientation ||UIInterfaceOrientationLandscapeRight == self.interfaceOrientation ) {
      windowRect = CGRectMake(windowRect.origin.y, windowRect.origin.x, windowRect.size.height, windowRect.size.width);
      viewRectAbsolute = CGRectMake(viewRectAbsolute.origin.y, viewRectAbsolute.origin.x, viewRectAbsolute.size.height, viewRectAbsolute.size.width);
    }
    frame.size.height -= [keyboardFrameValue CGRectValue].size.height - CGRectGetMaxY(windowRect) + CGRectGetMaxY(viewRectAbsolute);

    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:[[userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue]];
    [UIView setAnimationCurve:[[userInfo objectForKey:UIKeyboardAnimationCurveUserInfoKey] intValue]];
    _tableView.frame = frame;
    [UIView commitAnimations];

    UITableViewCell *textFieldCell = (id)((UITextField *)self.currentFirstResponder).superview.superview;
    NSIndexPath *textFieldIndexPath = [_tableView indexPathForCell:textFieldCell];

    // iOS 3 sends hide and show notifications right after each other
    // when switching between textFields, so cancel -scrollToOldPosition requests
    [NSObject cancelPreviousPerformRequestsWithTarget:self];
    _topmostRowBeforeKeyboardWasShown = [[_tableView indexPathsForVisibleRows] objectAtIndex:0];
    [_tableView scrollToRowAtIndexPath:textFieldIndexPath atScrollPosition:UITableViewScrollPositionMiddle animated:YES];
  }
}

- (void) scrollToOldPosition {
  [_tableView scrollToRowAtIndexPath:_topmostRowBeforeKeyboardWasShown atScrollPosition:UITableViewScrollPositionTop animated:YES];
}

- (void)keyboardWillHide:(NSNotification*)notification {
  if ([self currentFirstResponder] != nil) {

    NSDictionary* userInfo = [notification userInfo];

    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:[[userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue]];
    [UIView setAnimationCurve:[[userInfo objectForKey:UIKeyboardAnimationCurveUserInfoKey] intValue]];
    _tableView.frame = self.view.bounds;
    [UIView commitAnimations];

    [self performSelector:@selector(scrollToOldPosition) withObject:nil afterDelay:0.1];
  }
}   

@end