iphone - 为 UIImageView 的外观添加弹跳效果

Question

当我要将 UIImageView 作为 subview 显示时，如何添加弹跳效果？我是否必须使用 CoreAnimation 来执行此操作？我现在唯一的猜测是使用 CAKeyframeAnimation，如果有更好的方法请告诉我。这是我当前的代码:

 CABasicAnimation * theAnimation=[CABasicAnimation animationWithKeyPath:@"transform.translation.y"];
    theAnimation.delegate = self;
    theAnimation.duration = 1.0;
    theAnimation.fromValue = [NSNumber numberWithFloat:notif.center.y];
    theAnimation.toValue = [NSNumber numberWithFloat:notif.center.y-20];
    theAnimation.repeatCount = 3;

Answer 1

使用 CABasicAnimation 的 y 轴动画:

CGPoint origin = self.imageView.center;
CGPoint target = CGPointMake(self.imageView.center.x, self.imageView.center.y+100);
CABasicAnimation *bounce = [CABasicAnimation animationWithKeyPath:@"position.y"];
bounce.duration = 0.5;
bounce.fromValue = [NSNumber numberWithInt:origin.y];
bounce.toValue = [NSNumber numberWithInt:target.y];
bounce.repeatCount = 2;
bounce.autoreverses = YES;
[self.imageView.layer addAnimation:bounce forKey:@"position"];

如果你想实现缩小和增长，你必须添加一个 CGAffineTransformMakeScale，例如:

// grow
CGAffineTransform transform = CGAffineTransformMakeScale(1.3, 1.3);
imageView.transform = transform;