UIKeyboardWillChangeFrameNotification UIViewAnimationCurve设置为iOS 7上的7

Question

我希望确定键盘将如何动画。在iOS 6上，我得到了UIKeyboardAnimationCurveUserInfoKey的一个有效值(它应该是一个值为0-3的UIViewAnimationCurve )，但是函数返回的值是7。键盘是如何动画的？7的值能做些什么？

NSConcreteNotification 0xc472900 {name = UIKeyboardWillChangeFrameNotification; userInfo = {
    UIKeyboardAnimationCurveUserInfoKey = 7;
    UIKeyboardAnimationDurationUserInfoKey = "0.25";
    UIKeyboardBoundsUserInfoKey = "NSRect: {{0, 0}, {320, 216}}";
    UIKeyboardCenterBeginUserInfoKey = "NSPoint: {160, 588}";
    UIKeyboardCenterEndUserInfoKey = "NSPoint: {160, 372}";
    UIKeyboardFrameBeginUserInfoKey = "NSRect: {{0, 480}, {320, 216}}";
    UIKeyboardFrameChangedByUserInteraction = 0;
    UIKeyboardFrameEndUserInfoKey = "NSRect: {{0, 264}, {320, 216}}";
}}

Answer 1

似乎键盘使用的是一条未记录的/未知的动画曲线。

但你还是可以用的。若要将其转换为块动画的UIViewAnimationOptions，请将其移动16位，如下所示

UIViewAnimationCurve keyboardTransitionAnimationCurve;
[[notification.userInfo valueForKey:UIKeyboardAnimationCurveUserInfoKey]
                           getValue:&keyboardTransitionAnimationCurve];

keyboardTransitionAnimationCurve |= keyboardTransitionAnimationCurve<<16;

[UIView animateWithDuration:0.5
                  delay:0.0
                options:keyboardTransitionAnimationCurve
             animations:^{
                // ... do stuff here
           } completion:NULL];

或者把它当作动画曲线来传递。

UIViewAnimationCurve keyboardTransitionAnimationCurve;
[[notification.userInfo valueForKey:UIKeyboardAnimationCurveUserInfoKey]
                           getValue:&keyboardTransitionAnimationCurve];

[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:0.5];
[UIView setAnimationCurve:keyboardTransitionAnimationCurve];
// ... do stuff here
[UIView commitAnimations];

Answer 2

不幸的是，我不能发表评论，否则我将不会输入一个新的答案。

您还可以使用：

animationOptions |= animationCurve << 16；

这可能是首选的，因为它将保留以前在animationOptions上的OR =操作。

Answer 3

在Swift 4

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)
    }
}