UIImageView animationRepeatCount 奇怪的行为

UIImageView animationRepeatCount strange behaviour(UIImageView animationRepeatCount 奇怪的行为)

问题描述

所以我有这段代码可以无限次地为一组图像设置动画，但是一旦我尝试限制它动画的次数，它就根本不起作用.甚至没有显示图像.

So i have this code that animates a set of images an unlimited amount of times just fine, however as soon as i try to limit the number of times it animates it simply does not work. No image is even displayed.

有效的代码:

animatedMap.animationImages = [NSArray arrayWithObjects:
                               [UIImage imageNamed:@"0.gif"],
                               [UIImage imageNamed:@"1.gif"],
                               [UIImage imageNamed:@"2.gif"],
                               [UIImage imageNamed:@"3.gif"],
                               //etc...];
animatedMap.animationDuration = 20.0f;
animatedMap.animationRepeatCount = 0;
[animatedMap startAnimating];

不起作用的代码:

animatedMap.animationImages = [NSArray arrayWithObjects:
                               [UIImage imageNamed:@"0.gif"],
                               [UIImage imageNamed:@"1.gif"],
                               [UIImage imageNamed:@"2.gif"],
                               [UIImage imageNamed:@"3.gif"],
                               //etc...];
animatedMap.animationDuration = 20.0f;
animatedMap.animationRepeatCount = 1;
[animatedMap startAnimating];

这看起来真的很奇怪?

推荐答案

我注意到了同样的行为，我的解决方案是将动画代码的开头放在不同的位置.

I noticed the same behavior, my solution was to put the start of animation code in a different place.

对我来说，它是一个视图控制器，所以我将 imageView.startAnimating() 放在 viewWillAppear: 中，而不是 viewDidLoad:.

For me, it was a View Controller, so I put imageView.startAnimating() in viewWillAppear: instead of viewDidLoad:.

我不是 100% 了解问题所在，但可以假设动画不会触发，因为通过将 animationRepeatCount 设置为 1，您的一个动画"会在视图之前发生被陈列.更技术性地说，带有一个动画的 CATransaction::Commit 在视图显示之前执行，而不是在视图显示时执行.

I don't 100% understand what is the problem, but one can assume that the animation doesn't fire because by setting the animationRepeatCount to 1, your "one animation" happens before the view is displayed. To be more technical, the CATransaction::Commit with the one animation gets performed before the view is displayed, and not when the view is displayed.

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