iphone - 暂停 UIImageview 动画

我想暂停 UIImageView animation 并且根据我的研究发现您可以停止图像的动画，但不能暂停序列。通过在 stop animating 上调用语句 UIImageView 然后它停止动画并清空 ImageView 。

要暂停 UIImages 的动画，必须使用 NSTimer 。

我已经在应用程序中使用一个 NSTimer 来以不同的时间间隔一个接一个地加载 view controllers。我在每个 UIImages 中都有一个 view controller 的幻灯片。

问题是当定时器暂停时 view controllers 被暂停加载，但当时显示的 view controller 仍然重复显示该 UIImages 的 view controller 幻灯片，直到恢复暂停。所以我也想暂停那个幻灯片。

这是我使用 NSTimer 的地方

-(void)playpauseAction:(id)sender {
if([audioPlayer isPlaying])
{
    [sender setImage:[UIImage imageNamed:@"Play Icon.png"] forState:UIControlStateSelected];
    [audioPlayer pause];
    [self pauseTimer];
}else{
    [sender setImage:[UIImage imageNamed:@"pause.png"] forState:UIControlStateNormal];
    [audioPlayer play];
    [self resumeTimer];
if(isFirstTime == YES)
    {
     self.timer = [NSTimer scheduledTimerWithTimeInterval:11.0
                                         target:self
                                         selector:@selector(displayviewsAction:)
                                         userInfo:nil
                                        repeats:NO];
        isFirstTime  = NO;
    }
    }
    }

这就是 displayviewsAction 如何以不同的时间间隔一个接一个地加载 11 个 View Controller

- (void)displayviewsAction:(id)sender
 {
 First *firstController = [[First alloc] init];
 firstController.view.frame = CGRectMake(0, 0, 320, 480);
 CATransition *transitionAnimation = [CATransition animation];
 [transitionAnimation setDuration:1];
 [transitionAnimation setType:kCATransitionFade];
 [transitionAnimation setTimingFunction:[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn]];
 [self.view.layer addAnimation:transitionAnimation forKey:kCATransitionFade];
 [self.view addSubview:firstController.view];
 [self.view addSubview:toolbar];
 [firstController release];
 self.timer = [NSTimer scheduledTimerWithTimeInterval:23 target:self selector:@selector(Second) userInfo:nil repeats:NO];

 }

 -(void)Second
{
Second *secondController = [[Second alloc] init];
secondController.view.frame = CGRectMake(0, 0, 320, 480);
CATransition *transitionAnimation = [CATransition animation];
[transitionAnimation setDuration:1];
[transitionAnimation setType:kCATransitionReveal];
[transitionAnimation setTimingFunction:[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn]];
[self.view.layer addAnimation:transitionAnimation forKey:kCATransitionReveal];
[self.view addSubview:secondController.view];
[self.view addSubview:toolbar];
[secondController release];
self.timer = [NSTimer scheduledTimerWithTimeInterval:27 target:self selector:@selector(Third) userInfo:nil repeats:NO];
}

这就是在 View Controller 中启动图像动画的方式

// Displays UIImageView
UIImageView* ImageView = [[UIImageView alloc] initWithFrame:CGRectMake(10, 5, 300, 235)];
self.view.backgroundColor = [UIColor brownColor];
// load all the frames of our animation
ImageView.animationImages = [NSArray arrayWithObjects:
                                [UIImage imageNamed:@"1a.png"],
                                [UIImage imageNamed:@"1b.png"],
                                nil];

 // all frames will execute in 25 seconds
 ImageView.animationDuration = 25;
// start animating
[ImageView startAnimating];
ImageView.layer.borderWidth = 2;
ImageView.layer.borderColor = [[UIColor whiteColor]CGColor];
[ImageView.layer setMasksToBounds:YES];
[ImageView.layer setCornerRadius:15.0f];
[baseView addSubview:ImageView];

现在，如果有人可以指导我如何在 UIImage animation 暂停时暂停 NSTimer 的幻灯片。

感谢帮助。

最佳答案

您可以使用苹果提供的代码来暂停和恢复您的动画。

-(void)pauseLayer:(CALayer*)layer
{
CFTimeInterval pausedTime = [layer convertTime:CACurrentMediaTime() fromLayer:nil];
layer.speed = 0.0;
layer.timeOffset = pausedTime;
}

-(void)resumeLayer:(CALayer*)layer
{
CFTimeInterval pausedTime = [layer timeOffset];
layer.speed = 1.0;
layer.timeOffset = 0.0;
layer.beginTime = 0.0;
CFTimeInterval timeSincePause = [layer convertTime:CACurrentMediaTime() fromLayer:nil] - pausedTime;
layer.beginTime = timeSincePause;
}

并且要让 CALayer 传递给 pauseLayer 函数，您可以使用以下代码。

CALayer *player = ImageView.layer;
[self pauseLayer:player];

希望对你有帮助。

关于iphone - 暂停 UIImageview 动画，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/11103227/