iOS 7 - 键盘动画

Question

我正在尝试了解 iPhone 5 模拟器上 iOS 7.0 中的新键盘动画。我想在键盘出现时调整UITableView 的大小，但我无法获得正确的动画细节。
当键盘出现或消失时，我正在使用来自NSNotification 对象的信息。

这是我的日志：

Move keyboard from {{0, 920}, {320, 216}} to {{0, 352}, {320, 216}}
 with duration: 0.400000
 and animation curve: 7

UIViewAnimationCurveEaseInOut = 0
UIViewAnimationCurveEaseIn = 1
UIViewAnimationCurveEaseOut = 2
UIViewAnimationCurveLinear = 3

动画曲线是未知值，怎么办？

Answer 1

在 iOS 7 中，键盘使用了一种新的、未记录的动画曲线。虽然有些人注意到对动画选项使用未记录的值，但我更喜欢使用以下内容：

[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:[notification.userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue]];
[UIView setAnimationCurve:[notification.userInfo[UIKeyboardAnimationCurveUserInfoKey] integerValue]];
[UIView setAnimationBeginsFromCurrentState:YES];

// work

[UIView commitAnimations];

虽然建议使用基于块的动画，但从键盘通知返回的动画曲线是 UIViewAnimationCurve，而您需要传递给基于块的动画的选项是 UIViewAnimationOptions。使用传统的 UIView 动画方法，您可以直接将值通过管道输入。最重要的是，这将使用新的未记录动画曲线（整数值 7）并使动画与键盘匹配。而且，它同样适用于 iOS 6 和 7。

Answer 2

现在我找到了解决方案。动画从点{0, 920} 开始到{0, 352}。问题是UITableView对象以{160, 568}的大小开始，所以我在动画开始之前将UITableView的大小更改为{160, 920}。

关于未知动画曲线，我只是将参数设置为animationCurve << 16，将其从视图动画曲线转换为视图动画选项。
该值不等于线性、缓入、缓出和缓入动画曲线。

这是我的代码：

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

和：

- (void)keyboardWillShow:(NSNotification *)aNotification {
    NSDictionary *userInfo = aNotification.userInfo;

    //
    // Get keyboard size.

    NSValue *beginFrameValue = userInfo[UIKeyboardFrameBeginUserInfoKey];
    CGRect keyboardBeginFrame = [self.view convertRect:beginFrameValue.CGRectValue fromView:nil];

    NSValue *endFrameValue = userInfo[UIKeyboardFrameEndUserInfoKey];
    CGRect keyboardEndFrame = [self.view convertRect:endFrameValue.CGRectValue fromView:nil];

    //
    // Get keyboard animation.

    NSNumber *durationValue = userInfo[UIKeyboardAnimationDurationUserInfoKey];
    NSTimeInterval animationDuration = durationValue.doubleValue;

    NSNumber *curveValue = userInfo[UIKeyboardAnimationCurveUserInfoKey];
    UIViewAnimationCurve animationCurve = curveValue.intValue;

    //
    // Create animation.

    CGRect tableViewFrame = self.tableView.frame;
    bTableViewFrame.size.height = (keyboardBeginFrame.origin.y - tableViewFrame.origin.y);
    self.tableView.frame = tableViewFrame;

    void (^animations)() = ^() {
        CGRect tableViewFrame = self.tableView.frame;
        tableViewFrame.size.height = (keyboardEndFrame.origin.y - tableViewFrame.origin.y);
        self.tableView.frame = tableViewFrame;
    };

    //
    // Begin animation.

    [UIView animateWithDuration:animationDuration
                          delay:0.0
                        options:(animationCurve << 16)
                     animations:animations
                     completion:nil];
}

Answer 3

您可以使用animateWithDuration 块并在其中设置曲线。它很干净而且工作得很好。

UIViewAnimationCurve curve = [[notification.userInfo objectForKey:UIKeyboardAnimationCurveUserInfoKey] integerValue];
double duration = [[notification.userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];

[UIView animateWithDuration:duration
                    delay:0
                  options:UIViewAnimationOptionBeginFromCurrentState 
               animations:^{
                 [UIView setAnimationCurve:curve];
                 /* ANIMATION HERE */
                 // don't forget layoutIfNeeded if you use autolayout
               }
               completion:nil];

编码愉快！

更新

你可以使用我写的一个简单的UIViewController类https://github.com/Just-/UIViewController-KeyboardAnimation

Answer 4

请改用UIKeyboardWillChangeFrameNotification，因为一些国际键盘，如中文键盘，在使用过程中会改变高度。即使在横向模式下，此代码也可以为您提供正确的键盘高度。 （注意：下面的代码是Autolayout）

//set your observer, in a method like viewDidLoad
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillChange:) name:UIKeyboardWillChangeFrameNotification object:nil];

- (void)keyboardWillChange:(NSNotification *)notification {
    CGRect initialRect = [notification.userInfo[UIKeyboardFrameBeginUserInfoKey] CGRectValue];
    CGFloat initialHeight = self.view.frame.size.height - [self.view convertRect:initialRect fromView:nil].origin.y;
    CGRect keyboardRect = [notification.userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];
    CGFloat newHeight = self.view.frame.size.height - [self.view convertRect:keyboardRect fromView:nil].origin.y;
    //set your constraints here, based on initialHeight and newHeight, which are the heights of the keyboard before & after animation.
    [self.contentView setNeedsUpdateConstraints];
    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDuration:[notification.userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue]];
    [UIView setAnimationCurve:[notification.userInfo[UIKeyboardAnimationCurveUserInfoKey] integerValue]];
    [UIView setAnimationBeginsFromCurrentState:YES];
    [self.contentView layoutIfNeeded];
    [UIView commitAnimations];
}

Answer 5

要使用与键盘相同的动画，您必须使用未记录的曲线选项。

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

    CGRect rect = [userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];
    NSTimeInterval animationDuration = [[userInfo valueForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
    NSInteger curve = [[userInfo objectForKey:UIKeyboardAnimationCurveUserInfoKey] intValue] << 16;

    [UIView animateWithDuration:animationDuration delay:0.0 options:curve animations:^{

    } completion:nil];
}

我发现实际上animateWithDuration:delay:usingSpringWithDamping:initialSpringVelocity:options:animations:completion: 方法是现在在iOS7 和iOS8 中完成所有动画的新方法。您只需设置正确的持续时间、阻尼和速度，您将获得相同的效果，但您也可以更改速度/时间。

Answer 6

在 Swift 4 中

为键盘通知添加观察者：

• UIKeyboardDidShowNotification
• UIKeyboardDidHideNotification

通过

NSNotificationCenter.defaultCenter().addObserver(_ observer: Any, 
        selector aSelector: Selector, 
        name aName: NSNotification.Name?, 
        object anObject: Any?)

并实现选择器以使用键盘动画为 UI 设置动画。 为了创建一个有效的曲线值，我们需要将 UIResponder.keyboardAnimationCurveUserInfoKey 移动

func keyboardWillShow(_ notification: Notification!) {
    if let info = notification.userInfo {
        let keyboardSize = info[UIResponder.keyboardFrameEndUserInfoKey] as? CGRect
        let duration = info[UIResponder.keyboardAnimationDurationUserInfoKey] as? Double 
        let curveVal = (info[UIResponder.keyboardAnimationCurveUserInfoKey] as? NSNumber)?.intValue ?? 7 // default value for keyboard animation
        let options = UIView.AnimationOptions(rawValue: UInt(curveVal << 16))
        UIView.animate(withDuration: duration, delay: 0, options: options, animations: {
        // any operation to be performed
    }, completion: nil)
    }
}

Answer 7

在 iOS 13 中，您处于隐式动画中，因此只需在通知处理程序中修改您的布局，它就会以正确的持续时间和曲线进行动画处理。

Answer 8

注册接收通知：

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

通过动画更改视图的 frame.origin.y 来响应。

- (void)keyboardWillShow:(NSNotification *)aNotification {

    NSDictionary *userInfo = aNotification.userInfo;
    NSValue *endFrameValue = userInfo[UIKeyboardFrameEndUserInfoKey];
    CGRect keyboardEndFrame = [self.view convertRect:endFrameValue.CGRectValue fromView:nil];

    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:[aNotification.userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue]];
    [UIView setAnimationCurve:[aNotification.userInfo[UIKeyboardAnimationCurveUserInfoKey] integerValue]];
    [UIView setAnimationBeginsFromCurrentState:YES];

    CGRect searchButtonFrame = self.searchButton.frame;
    searchButtonFrame.origin.y = (keyboardEndFrame.origin.y - searchButtonFrame.size.height);
    self.searchButton.frame = searchButtonFrame;

    [UIView commitAnimations];
}