title: How to get UIButton position during animation
body: <p>This is my code  </p>
  
  <pre><code>- (void)viewDidLoad {
  [super viewDidLoad];
  self.timer = [NSTimer scheduledTimerWithTimeInterval:3.f target:self selector:@selector(creatButton) userInfo:nil repeats:YES];
  </code></pre>
  
  <p>}</p>
  
  <pre><code>- (NSMutableArray *)buttonsArray {
  if (!_buttonsArray) {
      _buttonsArray = [[NSMutableArray alloc] init];
  }
  return _buttonsArray;
  </code></pre>
  
  <p>}</p>
  
  <pre><code>- (void)creatButton {
  NSInteger j = arc4random() % 250;
  UIButton *countButton = [[UIButton alloc] initWithFrame:CGRectMake((j * 20) % ((NSInteger)self.view.frame.size.width - 120), -300, 100, 50)];
  
  [self.buttonsArray addObject:countButton];
  
  [self.view addSubview:countButton];
  
  [UIView animateWithDuration:9 delay:0.f
                      options:(UIViewAnimationOptionCurveLinear)
                      animations:^{
  
                          countButton.center = CGPointMake(50 + (j * 20) % ((NSInteger)self.view.frame.size.width - 120), self.view.frame.size.height);
                      }
                      completion:nil];
  </code></pre>
  
  <p>}</p>
  
  <p>and I want to know has any way to get <code>countButton</code>'s position while the animation is "in-flight".</p>