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

因此,经过数小时的艰苦工作,尝试使用这些当前的解决方案(完全失败),我终于让事情正常工作,并更新它们以使用新的动画块。我的回答完全基于Ortwin上面的回答。

所以不管出于什么原因,上面的代码就是不适合我。我的设置似乎和其他人的很相似,但可能是因为我用的是iPad或4.3……不知道。它在做一些古怪的数学运算然后把我的tableview从屏幕上拍下来。

见我的解决方案的最终结果:http://screencast.com/t/hjBCuRrPC(请忽略照片。: - p)

所以我沿用了Ortwin的基本原理,但改变了计算原点的方法。Y和尺寸。我的表格视图的高度和键盘的高度。当我从结果中减去窗口的高度时,它告诉我有多少交集。如果它大于0(也就是有一些重叠),我执行帧高度的动画。

此外,还有一些重绘问题得到了解决,1)等待滚动到单元格直到动画完成,2)使用UIViewAnimationOptionBeginFromCurrentState选项隐藏键盘。

有几件事需要注意。

_topmostrowbeforekeyboardwasshow & _originalFrame是在头文件中声明的实例变量。 自我。guestEntryTableView是我的tableView(我在外部文件中) iaskcgrecswap是Ortwin用于翻转帧坐标的方法 我只更新tableView的高度如果它至少有50px会显示 因为我不在UIViewController中,所以我没有self。视图,我只是把tableView返回到它的原始框架

同样,如果我Ortwin没有提供关键,我也不会得到这个答案。代码如下:

- (IBAction)textFieldDidBeginEditing:(UITextField *)textField
{
    self.activeTextField = textField;

    if ([self.guestEntryTableView indexPathsForVisibleRows].count) {
        _topmostRowBeforeKeyboardWasShown = (NSIndexPath*)[[self.guestEntryTableView indexPathsForVisibleRows] objectAtIndex:0];
    } else {
        // this should never happen
        _topmostRowBeforeKeyboardWasShown = [NSIndexPath indexPathForRow:0 inSection:0];
        [textField resignFirstResponder];
    }
}

- (IBAction)textFieldDidEndEditing:(UITextField *)textField
{
    self.activeTextField = nil;
}

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

    NSValue* keyboardFrameValue = [userInfo objectForKey:UIKeyboardFrameEndUserInfoKey];

    // Reduce the tableView height by the part of the keyboard that actually covers the tableView
    UIInterfaceOrientation orientation = [[UIApplication sharedApplication] statusBarOrientation];
    CGRect windowRect = [[UIApplication sharedApplication] keyWindow].bounds;
    CGRect viewRectAbsolute = [self.guestEntryTableView convertRect:self.guestEntryTableView.bounds toView:[[UIApplication sharedApplication] keyWindow]];
    CGRect keyboardFrame = [keyboardFrameValue CGRectValue];
    if (UIInterfaceOrientationLandscapeLeft == orientation ||UIInterfaceOrientationLandscapeRight == orientation ) {
        windowRect = IASKCGRectSwap(windowRect);
        viewRectAbsolute = IASKCGRectSwap(viewRectAbsolute);
        keyboardFrame = IASKCGRectSwap(keyboardFrame);
    }

    // fix the coordinates of our rect to have a top left origin 0,0
    viewRectAbsolute = FixOriginRotation(viewRectAbsolute, orientation, windowRect.size.width, windowRect.size.height);

    CGRect frame = self.guestEntryTableView.frame;
    _originalFrame = self.guestEntryTableView.frame;

    int remainder = (viewRectAbsolute.origin.y + viewRectAbsolute.size.height + keyboardFrame.size.height) - windowRect.size.height;

    if (remainder > 0 && !(remainder > frame.size.height + 50)) {
        frame.size.height = frame.size.height - remainder;
        float duration = [[userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
        [UIView animateWithDuration: duration
                        animations:^{
                            self.guestEntryTableView.frame = frame;
                        }
                        completion:^(BOOL finished){
                            UITableViewCell *textFieldCell = (UITableViewCell*) [[self.activeTextField superview] superview];
                            NSIndexPath *textFieldIndexPath = [self.guestEntryTableView indexPathForCell:textFieldCell];
                            [self.guestEntryTableView scrollToRowAtIndexPath:textFieldIndexPath atScrollPosition:UITableViewScrollPositionMiddle animated:YES];
                        }];
    }

}

- (void)keyboardWillHide:(NSNotification*)notification {
    NSDictionary* userInfo = [notification userInfo];
    float duration = [[userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
    [UIView animateWithDuration: duration
                          delay: 0.0
                        options: (UIViewAnimationOptionBeginFromCurrentState)
                     animations:^{
                         self.guestEntryTableView.frame = _originalFrame;
                     }
                     completion:^(BOOL finished){
                         [self.guestEntryTableView scrollToRowAtIndexPath:_topmostRowBeforeKeyboardWasShown atScrollPosition:UITableViewScrollPositionTop animated:YES];
                     }];

}   

#pragma mark CGRect Utility function
CGRect IASKCGRectSwap(CGRect rect) {
    CGRect newRect;
    newRect.origin.x = rect.origin.y;
    newRect.origin.y = rect.origin.x;
    newRect.size.width = rect.size.height;
    newRect.size.height = rect.size.width;
    return newRect;
}

CGRect FixOriginRotation(CGRect rect, UIInterfaceOrientation orientation, int parentWidth, int parentHeight) {
    CGRect newRect;
    switch(orientation)
    {
        case UIInterfaceOrientationLandscapeLeft:
            newRect = CGRectMake(parentWidth - (rect.size.width + rect.origin.x), rect.origin.y, rect.size.width, rect.size.height);
            break;
        case UIInterfaceOrientationLandscapeRight:
            newRect = CGRectMake(rect.origin.x, parentHeight - (rect.size.height + rect.origin.y), rect.size.width, rect.size.height);
            break;
        case UIInterfaceOrientationPortrait:
            newRect = rect;
            break;
        case UIInterfaceOrientationPortraitUpsideDown:
            newRect = CGRectMake(parentWidth - (rect.size.width + rect.origin.x), parentHeight - (rect.size.height + rect.origin.y), rect.size.width, rect.size.height);
            break;
    }
    return newRect;
}

执行滚动的函数可以简单得多:

- (void) textFieldDidBeginEditing:(UITextField *)textField {
    UITableViewCell *cell;

    if (floor(NSFoundationVersionNumber) <= NSFoundationVersionNumber_iOS_6_1) {
    // Load resources for iOS 6.1 or earlier
        cell = (UITableViewCell *) textField.superview.superview;

    } else {
        // Load resources for iOS 7 or later
        cell = (UITableViewCell *) textField.superview.superview.superview; 
       // TextField -> UITableVieCellContentView -> (in iOS 7!)ScrollView -> Cell!
    }
    [tView scrollToRowAtIndexPath:[tView indexPathForCell:cell] atScrollPosition:UITableViewScrollPositionTop animated:YES];
}

就是这样。根本不需要计算。

我尝试了几乎相同的方法,并提出了一个更简单、更小的代码。 我创建了一个IBOutlet iTextView,并与IB中的UITextView相关联。

 -(void)keyboardWillShow:(NSNotification *)notification
    {
        NSLog(@"Keyboard");
        CGRect keyFrame = [[[notification userInfo]objectForKey:UIKeyboardFrameEndUserInfoKey]CGRectValue];

        [UIView beginAnimations:@"resize view" context:nil];
        [UIView setAnimationCurve:1];
        [UIView setAnimationDuration:1.0];
        CGRect frame = iTableView.frame;
        frame.size.height = frame.size.height -  keyFrame.size.height;
        iTableView.frame = frame;
        [iTableView scrollRectToVisible:frame animated:YES];
        [UIView commitAnimations];

    }

这个解决方案为我工作,请注意这一行

[tableView setContentOffset:CGPointMake(0.0, activeField.frame.origin.y-kbSize.height+160) animated:YES];

您可以更改160值以使其与您的工作相匹配

- (void)keyboardWasShown:(NSNotification*)aNotification
{
    NSDictionary* info = [aNotification userInfo];
    CGSize kbSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;
    CGRect bkgndRect = activeField.superview.frame;
                        bkgndRect.size.height += kbSize.height;
     [activeField.superview setFrame:bkgndRect];
     [tableView setContentOffset:CGPointMake(0.0, activeField.frame.origin.y-kbSize.height+160) animated:YES];
}

- (void)textFieldDidBeginEditing:(UITextField *)textField
{
   activeField = textField;
}
-(void)textFieldDidEndEditing:(UITextField *)textField
 {
     activeField = nil;
 }
// Called when the UIKeyboardWillHideNotification is sent
- (void)keyboardWillBeHidden:(NSNotification*)aNotification
{
    UIEdgeInsets contentInsets = UIEdgeInsetsZero;
    tableView.contentInset = contentInsets;
    tableView.scrollIndicatorInsets = contentInsets;
    NSDictionary* info = [aNotification userInfo];
    CGSize kbSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;
    CGRect bkgndRect = activeField.superview.frame;
    //bkgndRect.size.height += kbSize.height;
    [activeField.superview setFrame:bkgndRect];
    [tableView setContentOffset:CGPointMake(0.0, activeField.frame.origin.y-kbSize.height) animated:YES];
}

我想我已经想出了与苹果应用程序行为相匹配的解决方案。

首先,在viewWillAppear:订阅键盘通知,这样你就知道什么时候键盘会显示和隐藏,系统会告诉你键盘的大小,但不要忘记在viewWillDisappear:中取消注册。

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

实现类似于下面的方法,以便在键盘显示时调整tableView的大小以匹配可见区域。这里我单独跟踪键盘的状态,所以我可以自己选择何时将tableView设置为全高度,因为你在每个字段更改时都会收到这些通知。不要忘记实现keyboardWillHide:并选择适当的地方来修复你的tableView大小。

-(void) keyboardWillShow:(NSNotification *)note
{
    CGRect keyboardBounds;
    [[note.userInfo valueForKey:UIKeyboardBoundsUserInfoKey] getValue: &keyboardBounds];
    keyboardHeight = keyboardBounds.size.height;
    if (keyboardIsShowing == NO)
    {
        keyboardIsShowing = YES;
        CGRect frame = self.view.frame;
        frame.size.height -= keyboardHeight;

        [UIView beginAnimations:nil context:NULL];
        [UIView setAnimationBeginsFromCurrentState:YES];
        [UIView setAnimationDuration:0.3f];
        self.view.frame = frame;
        [UIView commitAnimations];
    }
}

现在这是滚动位,我们先计算出一些大小,然后我们看到我们在可见区域中的位置,并设置我们想要滚动的矩形,根据它在视图中的位置,将它设置为文本字段中间上方或下方的半视图。在本例中,我们有一个UITextFields数组和一个用于跟踪它们的enum,因此用rowHeight乘以行号就得到了这个外部视图中帧的实际偏移量。

- (void) textFieldDidBeginEditing:(UITextField *)textField
{
    CGRect frame = textField.frame;
    CGFloat rowHeight = self.tableView.rowHeight;
    if (textField == textFields[CELL_FIELD_ONE])
    {
        frame.origin.y += rowHeight * CELL_FIELD_ONE;
    }
    else if (textField == textFields[CELL_FIELD_TWO])
    {
        frame.origin.y += rowHeight * CELL_FIELD_TWO;
    }
    else if (textField == textFields[CELL_FIELD_THREE])
    {
        frame.origin.y += rowHeight * CELL_FIELD_THREE;
    }
    else if (textField == textFields[CELL_FIELD_FOUR])
    {
        frame.origin.y += rowHeight * CELL_FIELD_FOUR;
    }
    CGFloat viewHeight = self.tableView.frame.size.height;
    CGFloat halfHeight = viewHeight / 2;
    CGFloat midpoint = frame.origin.y + (textField.frame.size.height / 2);
    if (midpoint < halfHeight)
    {
        frame.origin.y = 0;
        frame.size.height = midpoint;
    }
    else
    {
        frame.origin.y = midpoint;
        frame.size.height = midpoint;
    }
    [self.tableView scrollRectToVisible:frame animated:YES];
}

这似乎工作得很好。