新浪微博加号按钮动画实现方案

1.使用UIView的动画实现：

+ (void)animateWithDuration:(NSTimeInterval)duration

delay:(NSTimeInterval)delay

usingSpringWithDamping:(CGFloat)dampingRatio

initialSpringVelocity:(CGFloat)velocity

options:(UIViewAnimationOptions)options

animations:(void (^)(void))animations

completion:(void (^)(BOOL finished))completion

该方法的使用可见：http://blog.csdn.net/jacob_ios/article/details/51678444

2.动画方案二：

CABasicAnimation *positionAnimation;

positionAnimation = [CABasicAnimation animationWithKeyPath:@"position"];

positionAnimation.fromValue = [NSValue valueWithCGPoint:fromPosition];

positionAnimation.toValue = [NSValue valueWithCGPoint:toPosition];

整个实现的详细过程代码：https://github.com/xinyuly/XYMenuAnimateView