每次动画重复时调用一个方法(Call a method every time animation repeats)

每次动画重复时调用一个方法(Call a method every time animation repeats)

我需要在动画重复之前调用某个方法。 我不知道在哪里放置那行代码。

这是我为对象设置动画的代码：

[UIView animateWithDuration:speed delay:delay options:UIViewAnimationOptionAllowUserInteraction|UIViewAnimationOptionCurveLinear|UIViewAnimationOptionRepeat animations:^(void){ cloud.frame = (CGRectMake(cloud.frame.origin.x, cloud.frame.origin.y+600, cloud.frame.size.width, cloud.frame.size.height)); }completion:^(BOOL finished){ if (finished){ [cloud setBackgroundImage:[UIImage imageNamed:@"cloudWhite.png"] forState:UIControlStateNormal]; } }];

完成部分中调用的方法将不会在每次重复之前执行，而是仅在整个动画完成之后执行，并且在重复之后 - 在这种情况下 - 从不执行。

我的问题是，如何在每个动画重复之前调用一个方法？

I need to call a certain method before my animation repeats. I don't know where to place that line of code.

This is my code for animating an object:

[UIView animateWithDuration:speed delay:delay options:UIViewAnimationOptionAllowUserInteraction|UIViewAnimationOptionCurveLinear|UIViewAnimationOptionRepeat animations:^(void){ cloud.frame = (CGRectMake(cloud.frame.origin.x, cloud.frame.origin.y+600, cloud.frame.size.width, cloud.frame.size.height)); }completion:^(BOOL finished){ if (finished){ [cloud setBackgroundImage:[UIImage imageNamed:@"cloudWhite.png"] forState:UIControlStateNormal]; } }];

Method called in completion part will not be executed before every repeat but only after whole animation is complete, together with al repeats - which is, in this case - never.

My question is, how to call a method before every animation repeat?

最满意答案

我建议重构你的动画，这样它就不会使用UIViewAnimationOptionRepeat 。 相反，编写一个执行动画的单个循环的方法。 然后添加一个以递归方式调用该方法的完成方法块。

您还可以在完成块中的动画的每次迭代中放置要触发的方法调用。

I would suggest refactoring your animation so it does not use UIViewAnimationOptionRepeat. Instead, write a method that executes a single cycle of your animation. Then add a completion method block that calls the method recursively.

You can also put the method call that you want to fire on each iteration of your animation in the completion block.