我想沿圆形路径实现动画，并在动画结束后立即触发完成功能。
感谢这篇文章，我想出了如何使用CAKeyframeAnimation和CGMutablePathRef沿路径执行动画。
CAKeyframeAnimation *pathAnimation = [CAKeyframeAnimation animationWithKeyPath:@"position"];
pathAnimation.calculationMode = kCAAnimationPaced;
pathAnimation.fillMode = kCAFillModeForwards;
pathAnimation.removedOnCompletion = NO;
pathAnimation.duration = 1.0;
CGPoint endPoint = CGPointMake(self.boardReference.view.bounds.size.width/2,self.boardReference.view.bounds.size.height/2);
CGMutablePathRef curvedPath = CGPathCreateMutable();
CGPathMoveToPoint(curvedPath, NULL, self.view.center.x, self.view.center.y);
CGPathAddCurveToPoint(curvedPath, NULL, endPoint.x, self.view.center.y, endPoint.x, self.view.center.y, endPoint.x, endPoint.y);
pathAnimation.path = curvedPath;
CGPathRelease(curvedPath);
[self.view.layer addAnimation:pathAnimation forKey:@"curvedPath"];
[self addNewCardAtPoint:endPoint]; //This should only be launched after the animation has been finished
问题：我的方法addNewCardAtPoint只能在动画完成后调用。目前该过程没有阻塞，因此该方法或多或少同时被调用。
在第一个视图中， animateWithDuration 函数似乎更适合，因为它为动画和完成动作定义了块。但是简单的将 CAKeyframeAnimation 添加到动画块中，结果基本相同，立即执行完成块。
[UIView animateWithDuration:0.8
animations:^{
NSLog(@"-Animate on curved path to end point-");
... //how perform the same path based animation here?
} completion:^(BOOL finished) {
[self addNewCardAtPoint:self.view.center];
}
];
只有在沿着弯曲路径的动画完成后，如何才能触发完整的功能？