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 4.2完整解决方案

我用一组协议创建了GIST,它简化了显示、隐藏或更改键盘时添加额外空间的工作。

特点:

正确使用键盘帧变化(例如,键盘高度变化,如emojii→普通键盘)。 标签栏和工具栏支持UITableView的例子(在其他例子你收到不正确的插入)。 动态动画持续时间(非硬编码)。 面向协议的方法,可以很容易地为您的目的进行修改。

使用

包含一些滚动视图(当然也支持表格视图)的视图控制器的基本用法示例。

class SomeViewController: UIViewController {
  @IBOutlet weak var scrollView: UIScrollView!

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

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

extension SomeViewController: ModifableInsetsOnKeyboardFrameChanges {
  var scrollViewToModify: UIScrollView { return scrollView }
}

核心:帧改变观察者

协议KeyboardChangeFrameObserver将在每次键盘帧被改变时触发事件(包括显示,隐藏,帧改变)。

在viewWillAppear()或类似方法调用addKeyboardFrameChangesObserver()。 在viewWillDisappear()或类似的方法调用removeKeyboardFrameChangesObserver()。

实现:滚动视图

ModifableInsetsOnKeyboardFrameChanges协议将UIScrollView支持添加到核心协议。当键盘帧改变时,它改变滚动视图的嵌入。

你的类需要设置滚动视图,一个人的插入将增加/减少键盘帧的变化。

var scrollViewToModify: UIScrollView { get }

其他回答

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

另一个简单的方法(只适用于一个部分)

//cellForRowAtIndexPath
UItextField *tf;
[cell addSubview:tf];
tf.tag = indexPath.row;
tf.delegate = self;

//textFieldDidBeginEditing:(UITextField *)text
[[self.tableView scrollToRowsAtIndexPath:[NSIndexPath indexPathForRow:text.tag in section:SECTIONINTEGER] animated:YES];

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

基于bartjomiej semazynk解决方案的Swift 3最简单的解决方案:

override func viewDidLoad() {
    super.viewDidLoad()

    NotificationCenter.default.addObserver(self, selector: #selector(CreateEditRitualViewController.keyboardWillShow(notification:)), name: NSNotification.Name.UIKeyboardDidShow, object: nil)
    NotificationCenter.default.addObserver(self, selector: #selector(CreateEditRitualViewController.keyboardWillHide(notification:)), name: NSNotification.Name.UIKeyboardDidHide, object: nil)
}

deinit {
    NotificationCenter.default.removeObserver(self)
}

// MARK: Keyboard Notifications

@objc func keyboardWillShow(notification: NSNotification) {
    if let keyboardHeight = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue.height {
        tableView.contentInset = UIEdgeInsetsMake(0, 0, keyboardHeight, 0)
    }
}

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

Swift 3-4动画和键盘帧改变的解决方案:

首先,创建Bool类型:

// MARK: - Private Properties
private var isKeyboardShowing = false

其次,在系统键盘通知中添加观察者:

// MARK: - Overriding ViewController Life Cycle Methods
override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)

    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow), name: .UIKeyboardWillShow, object: nil)

    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide), name: .UIKeyboardWillHide, object: nil)

    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillChangeFrame), name: .UIKeyboardWillChangeFrame, object: nil)
}

第三,准备动画功能:

func adjustTableViewInsets(keyboardHeight: CGFloat, duration: NSNumber, curve: NSNumber){
    var extraHeight: CGFloat = 0
    if keyboardHeight > 0 {
        extraHeight = 20
        isKeyboardShowing = true
    } else {
        isKeyboardShowing = false
    }

    let contentInset = UIEdgeInsets(top: 0, left: 0, bottom: keyboardHeight + extraHeight, right: 0)
    func animateFunc() {
        //refresh constraints
        //self.view.layoutSubviews()
        tableView.contentInset = contentInset
    }

    UIView.animate(withDuration: TimeInterval(duration), delay: 0, options: [UIViewAnimationOptions(rawValue: UInt(curve))], animations: animateFunc, completion: nil)
}

然后添加target/action方法(由观察者调用):

// MARK: - Target/Selector Actions
func keyboardWillShow(notification: NSNotification) {
    if !isKeyboardShowing {
        if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
            let keyboardHeight = keyboardSize.height

            let duration = notification.userInfo?[UIKeyboardAnimationDurationUserInfoKey] as! NSNumber
            let curve = notification.userInfo?[UIKeyboardAnimationCurveUserInfoKey] as! NSNumber

            adjustTableViewInsets(keyboardHeight: keyboardHeight, duration: duration, curve: curve)
        }
    }
}

func keyboardWillHide(notification: NSNotification) {
    let duration = notification.userInfo?[UIKeyboardAnimationDurationUserInfoKey] as! NSNumber
    let curve = notification.userInfo?[UIKeyboardAnimationCurveUserInfoKey] as! NSNumber
    adjustTableViewInsets(keyboardHeight: 0, duration: duration, curve: curve)
}

func keyboardWillChangeFrame(notification: NSNotification) {
    if isKeyboardShowing {
        let duration = notification.userInfo?[UIKeyboardAnimationDurationUserInfoKey] as! NSNumber
        let curve = notification.userInfo?[UIKeyboardAnimationCurveUserInfoKey] as! NSNumber

        if let newKeyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
            let keyboardHeight = newKeyboardSize.height
            adjustTableViewInsets(keyboardHeight: keyboardHeight, duration: duration, curve: curve)
        }
    }
}

最后,不要忘记在deinit或viewWillDisappear中删除观察者:

deinit {
    NotificationCenter.default.removeObserver(self)
}