Swift 4.2的小变化…

在我的UITableView上，我有很多部分，但我必须避免浮动标题效果，所以我使用了“dummyViewHeight”方法，就像在Stack Overflow上看到的其他地方一样… 这就是我对这个问题的解决方案(它也适用于键盘+工具栏+建议):

将其声明为类常量:

let dummyViewHeight: CGFloat = 40.0

Then

override func viewDidLoad() {
    super.viewDidLoad()
    //... some stuff here, not needed for this example

    // Create non floating header
    tableView.tableHeaderView = UIView(frame: CGRect(x: 0, y: 0, width: tableView.bounds.size.width, height: dummyViewHeight))
    tableView.contentInset = UIEdgeInsets(top: -dummyViewHeight, left: 0, bottom: 0, right: 0)

    addObservers()
}

override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)
    removeObservers()
}

这里所有的魔法……

@objc func keyboardWillShow(notification: NSNotification) {
    if let userInfo = notification.userInfo {
        let keyboardHeight = (userInfo[UIResponder.keyboardFrameEndUserInfoKey] as AnyObject).cgRectValue.size.height
        tableView.tableHeaderView = UIView(frame: CGRect(x: 0, y: 0, width: self.tableView.bounds.size.width, height: dummyViewHeight))
        tableView.contentInset = UIEdgeInsets(top: -dummyViewHeight, left: 0, bottom: keyboardHeight, right: 0)
    }
}

@objc func keyboardWillHide(notification: NSNotification) {
    UIView.animate(withDuration: 0.25) {
        self.tableView.tableHeaderView = UIView(frame: CGRect(x: 0, y: 0, width: self.tableView.bounds.size.width, height: self.dummyViewHeight))
        self.tableView.contentInset = UIEdgeInsets(top: -self.dummyViewHeight, left: 0, bottom: 0, right: 0)
    }
}

在Swift中的一个例子，使用从UITableViewCell中获取UITextField的indexPath的文本字段的确切点:

func textFieldDidBeginEditing(textField: UITextField) {
    let pointInTable = textField.convertPoint(textField.bounds.origin, toView: self.accountsTableView)
    let textFieldIndexPath = self.accountsTableView.indexPathForRowAtPoint(pointInTable)
    accountsTableView.scrollToRowAtIndexPath(textFieldIndexPath!, atScrollPosition: .Top, animated: true)
}

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

简单快捷的解决方案。

我只要滚动到右边的单元格

    - (void)scrollViewDidScroll:(UIScrollView *)scrollView 

假设我知道表现在处于这个模式_keepMyCellOnTop &我知道选定单元格“_selectedCellIndex”或滚动到选定单元格

- (void)scrollViewDidScroll:(UIScrollView *)scrollView 
{

    if (_keepMyCellOnTop)
    {
        [self.tableView scrollToRowAtIndexPath:_selectedCellIndex atScrollPosition:UITableViewScrollPositionTop animated:NO];
    }
}

这将防止滚动。

将代码放在-(void) scrollViewDidEndScrollingAnimation:(UIScrollView *)scrollView中 结果是上下滚动吗

在viewdidload

-(void)viewdidload{

[super viewdidload];

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

    -(void)keyboardWillChange:(NSNotification*)sender{

        NSLog(@"keyboardwillchange sender %@",sender);

float margin=0  // set your own topmargin


        CGFloat originY = [[sender.userInfo objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].origin.y;


        if (originY >= self.view.frame.size.height){

            NSLog(@"keyboardclose");



            [tb_ setFrame:CGRectMake(0, margin, self.view.frame.size.width, self.view.frame.size.height-margin)];

        }else{

            NSLog(@"keyobard on");

            float adjustedHeight = self.view.frame.size.height - margin - (self.view.frame.size.height-originY);

            [tb_ setFrame:CGRectMake(0, margin, self.view.frame.size.width, adjustedHeight)];
        }







    }