ios - UIView动画: simulating velocity

Question

我正在尝试使用 UIView 动画将 View 简单地移动到屏幕上:

  [UIView animateWithDuration:.10 delay:0 options: nil animations:^
   {
       self.menusView.frame = endingMenuViewFrame;;
   }
    completion:^(BOOL finished)
   {

   }];

我想添加一个动画，以便 UIView 在它下降之前到达顶部时漂浮一点，即类似于如果有人在空中跳跃 - 当他们第一次跳跃时，他们会快速向上弹起，然后重力当他们到达跳跃的顶点时，逐渐减慢他们的速度，并最终将他们推回地面。有谁知道如何做到这一点？

Answer 1

试试这个代码。每次你的高度减少一半时，这将使你的 View 反弹三次。您可以添加更多退回邮件。

CGFloat offset = 200.0;

CGRect originalFrame = self.menusView.frame;

[UIView animateWithDuration:1.0 animations:^{
    CGRect frame = self.runnerAlertView.frame;
    frame.origin.y = frame.origin.y - offset;
    self.menusView.frame = frame;
} completion:^(BOOL finished){
    [UIView animateWithDuration:1.0 animations:^{

        self.menusView.frame = originalFrame;
    } completion:^(BOOL finished) {
        [UIView animateWithDuration:1.0 animations:^{
            CGRect frame = self.menusView.frame;
            frame.origin.y = frame.origin.y - 0.5 *offset;
            self.menusView.frame = frame;
        } completion:^(BOOL finished){
            [UIView animateWithDuration:1.0 animations:^{

                self.menusView.frame = originalFrame;
            } completion:^(BOOL finished) {
                [UIView animateWithDuration:1.0 animations:^{
                    CGRect frame = self.runnerAlertView.frame;
                    frame.origin.y = frame.origin.y - 0.25 * offset;
                    self.menusView.frame = frame;
                } completion:^(BOOL finished){
                    [UIView animateWithDuration:1.0 animations:^{

                        self.menusView.frame = originalFrame;
                    }];
            }];
        }];
        }];
    }];
}];