ios - 如何循环动画几次或几秒钟？

Question

我发现了几个相关的问题，比如this ，但我仍然需要一点帮助。 我想要的是一个按钮，一旦点击，就会以下列任一方式随机飞行: 1，它飞过五个随机位置并飞回原来的位置。或者 2、随机飞行2秒，然后回到原位。

这是我的代码，但仍然缺少停止控件:

   //if the button clicked
    [self animationLoop:@"Wrong!" finished:1 context:nil];
    -(void)animationLoop:(NSString *)animationID finished:(int)finished context:(void *)context {
   [UIView beginAnimations:nil context:nil];
   [UIView setAnimationDuration:1];
   [UIView setAnimationRepeatCount:finished];

   CGFloat x = (CGFloat) (arc4random() % (int) self.view.bounds.size.width);
   CGFloat y = (CGFloat) (arc4random() % (int) self.view.bounds.size.height);
   CGPoint squarePostion = CGPointMake(x, y);
   theWrongButton.center = squarePostion;

   [UIView setAnimationDelegate:self];
   [UIView setAnimationDidStopSelector:@selector(animationLoop:finished:context:)];

  [UIView commitAnimations];
  }

我想我的问题有点像如何让动画循环几次或几秒钟。

Answer 1

您要问的正是上下文参数的用途。它使您能够传入以后可以使用的任何对象。例如，您可能正在寻找这样的内容:

    [self animationLoop:@"Wrong!" finished:1 context:[NSNumber numberWithInt:0]];
-(void)animationLoop:(NSString *)animationID finished:(int)finished context:(void *)context {

    NSNumber *count = (NSNumber *)context;
    if ([count intValue]) >= 5) {
        return;
    }
    [UIView beginAnimations:nil context:[NSNumber numberWithInt:[count intValue]+1]];
    [UIView setAnimationDuration:1];
    [UIView setAnimationRepeatCount:finished];

    CGFloat x = (CGFloat) (arc4random() % (int) self.view.bounds.size.width);
    CGFloat y = (CGFloat) (arc4random() % (int) self.view.bounds.size.height);
    CGPoint squarePostion = CGPointMake(x, y);
    theWrongButton.center = squarePostion;

    [UIView setAnimationDelegate:self];
    [UIView setAnimationDidStopSelector:@selector(animationLoop:finished:context:)];

   [UIView commitAnimations];
   }