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

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)
}

如果你使用UITableViewController而不是UIViewController,它会自动这样做。

这非常有效,在iPad上也是如此。

- (BOOL)textFieldShouldReturn:(UITextField *)textField 
{

    if(textField == textfield1){
            [accountName1TextField becomeFirstResponder];
        }else if(textField == textfield2){
            [self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:0 inSection:1] atScrollPosition:UITableViewScrollPositionTop animated:YES];
            [textfield3 becomeFirstResponder];

        }else if(textField == textfield3){
            [self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:1 inSection:1] atScrollPosition:UITableViewScrollPositionTop animated:YES];
            [textfield4 becomeFirstResponder];

        }else if(textField == textfield4){
            [self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:2 inSection:1] atScrollPosition:UITableViewScrollPositionTop animated:YES];
            [textfield5 becomeFirstResponder];

        }else if(textField == textfield5){
            [self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:3 inSection:1] atScrollPosition:UITableViewScrollPositionTop animated:YES];
            [textfield6 becomeFirstResponder];

        }else if(textField == textfield6){
            [self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:4 inSection:1] atScrollPosition:UITableViewScrollPositionTop animated:YES];
            [textfield7 becomeFirstResponder];

        }else if(textField == textfield7){
            [self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:5 inSection:1] atScrollPosition:UITableViewScrollPositionTop animated:YES];
            [textfield8 becomeFirstResponder];

        }else if(textField == textfield8){
            [self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:6 inSection:1] atScrollPosition:UITableViewScrollPositionTop animated:YES];
            [textfield9 becomeFirstResponder];

        }else if(textField == textfield9){
            [self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:7 inSection:1] atScrollPosition:UITableViewScrollPositionTop animated:YES];
            [textField resignFirstResponder];
        }

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。

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;
}