相关疑难解决方法(0)

我搜索了很多SO的东西和Apple的参考资料,但仍然无法解决我的问题.

是)我有的:

1. 屏幕与2 UIImageViews nad连接2 UIButtons
2. 2种动画:
   2.1.第一个是向上扩展,然后在viewDidLoad 2.2中一个接一个地向下移动每个图像.第二个,当按下按钮(这是自定义按钮,隐藏在每个UIImageView的'内部')时,它会触发相应UIImageView的动画 - 只有一个,而不是两个 - (也可以向上扩展,然后向下).
3. 当我为iOS4 +写作时,我被告知要使用基于块的动画!

我需要的:

如何取消正在运行的动画？除了最后一个,我设法取消了...:/这是我的代码片段:

[UIImageView animateWithDuration:2.0 
                               delay:0.1 
                             options:UIViewAnimationOptionAllowUserInteraction 
                          animations:^{
        isAnimating = YES;
        self.bigLetter.transform = CGAffineTransformScale(self.bigLetter.transform, 2.0, 2.0);
    } completion:^(BOOL finished){
        if(! finished) return;
        [UIImageView animateWithDuration:2.0 
                                   delay:0.0 
                                 options:UIViewAnimationOptionAllowUserInteraction 
                              animations:^{
            self.bigLetter.transform = CGAffineTransformScale(self.bigLetter.transform, 0.5, 0.5);
        } completion:^(BOOL finished){
            if(! finished) return;
            [UIImageView animateWithDuration:2.0 
                                       delay:0.0 
                                     options:UIViewAnimationOptionAllowUserInteraction 
                                  animations:^{
                self.smallLetter.transform = CGAffineTransformScale(self.smallLetter.transform, 2.0, 2.0);
            } completion:^(BOOL finished){
                if(! finished) return;
                [UIImageView animateWithDuration:2.0 
                                           delay:0.0 
                                         options:UIViewAnimationOptionAllowUserInteraction 
                                      animations:^{
                    self.smallLetter.transform = CGAffineTransformScale(self.smallLetter.transform, 0.5, 0.5);
                }
                                      completion:^(BOOL …