iOS动画相关(持续更新)

1.When my application is entering background, because the user push the home button, the animations correctly set in pause, but when i re-open my app, the animations have disappeard.How could i fix it please ?

当我的应用进入了后台,因为用户按了home键,动画被设置成了暂停,但当我重新打开应用时,动画都消失了,我如何修复它?

This is correct and built-in behavior. When you leave the app, all animations are removed from their layers: the system calls removeAllAnimations on every layer.

你的情况是系统默认的行为.当你离开了应用后(比如进入了后台),所有的动画都从他们的layer上移除了:因为系统调用了removeAllAnimations,针对所有的layer.

附录:

UIViewController中的view显示步骤

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进入UIViewController时的情况:

viewDidLoad
viewWillLayoutSubviews
viewDidLayoutSubviews
viewWillAppear
viewWillLayoutSubviews
viewDidLayoutSubviews
viewDidAppear

切换了Controller后的情况(比如你在TabbarController中切换了):

viewWillDisappear
viewDidDisappear

再次切换回来后的情况:
viewWillLayoutSubviews
viewDidLayoutSubviews
viewWillAppear
viewWillLayoutSubviews
viewDidLayoutSubviews
viewDidAppear

退入到后台后的情况:

无

从后台进入程序时的情况:

viewWillLayoutSubviews
viewDidLayoutSubviews

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为了解决从后台切换回来或者从TabbarController切换回来动画还能继续动画效果,需要如下的解决方案:

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];

    // 添加通知(处理从后台进来后的情况)
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(addAnimation:)
                                                 name:UIApplicationWillEnterForegroundNotification
                                               object:nil];

    // 添加动画的代码
}

- (void)addAnimation:(NSNotification *)notificaiton
{
　 　// 添加动画的代码
}

2.基本动画类型

旋转动画

/* 旋转 */
    CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];

    // 一次完整的动画所持续的时间
    animation.duration = 1.f;

    // 重复次数
    animation.repeatCount = HUGE_VALF;

    // 起始角度
    animation.fromValue = [NSNumber numberWithFloat:0.0];

    // 终止角度
    animation.toValue   = [NSNumber numberWithFloat:- 2 * M_PI];

    // 添加动画
    [_showView.layer addAnimation:animation
                           forKey:@"rotate-layer"];

透明度

// 透明度动画
    CABasicAnimation* fadeAnim = [CABasicAnimation animationWithKeyPath:@"opacity"];

    // 初始值
    fadeAnim.fromValue = [NSNumber numberWithFloat:1.0];

    // 结束值
    fadeAnim.toValue   = [NSNumber numberWithFloat:0.0];

    // 动画持续一次的时间
    fadeAnim.duration = 1.0;

    // 开始动画
    [_showView.layer addAnimation:fadeAnim forKey:@"opacity"];

    // 无论动画是否被中断,其最终的值还是被设置过了
    _showView.layer.opacity = 0.0;

borderWidth动画

// borderWidth动画
    CABasicAnimation *borderWidthAnimation = \
        [CABasicAnimation animationWithKeyPath:@"borderWidth"];

    // 初始值
    borderWidthAnimation.fromValue = [NSNumber numberWithFloat:0.0];

    // 结束值
    borderWidthAnimation.toValue   = [NSNumber numberWithFloat:3.0];

    // 动画持续一次的时间
    borderWidthAnimation.duration    = 1.f;

    // 开始动画
    [_showView.layer addAnimation:borderWidthAnimation forKey:@"borderWidth"];

    // 无论动画是否被中断,其最终的值还是被设置过了
    _showView.layer.borderWidth = 3.0f;

backgroundColor动画

// backgroundColor动画
    CABasicAnimation *borderWidthAnimation = \
        [CABasicAnimation animationWithKeyPath:@"backgroundColor"];

    // 初始值
    borderWidthAnimation.fromValue = (id)[[UIColor redColor] CGColor];

    // 结束值
    borderWidthAnimation.toValue   = (id)[[UIColor greenColor] CGColor];

    // 动画持续一次的时间
    borderWidthAnimation.duration    = 1.f;

    // 开始动画
    [_showView.layer addAnimation:borderWidthAnimation forKey:@"borderWidth"];

    // 无论动画是否被中断,其最终的值还是被设置过了
    _showView.layer.backgroundColor = [[UIColor greenColor] CGColor];

borderColor动画

// borderColor动画
    CABasicAnimation *borderWidthAnimation = \
        [CABasicAnimation animationWithKeyPath:@"borderColor"];

    // 初始值
    borderWidthAnimation.fromValue = (id)[[UIColor redColor] CGColor];

    // 结束值
    borderWidthAnimation.toValue   = (id)[[UIColor greenColor] CGColor];

    // 动画持续一次的时间
    borderWidthAnimation.duration    = 1.f;

    // 开始动画
    [_showView.layer addAnimation:borderWidthAnimation forKey:@"borderWidth"];

    // 无论动画是否被中断,其最终的值还是被设置过了
    _showView.layer.backgroundColor = [[UIColor greenColor] CGColor];

 bounds.size.height动画

// bounds.size.height动画
    CABasicAnimation *borderWidthAnimation = \
        [CABasicAnimation animationWithKeyPath:@"bounds.size.height"];

    // 初始值
    borderWidthAnimation.fromValue = [NSNumber numberWithFloat:100.0f];

    // 结束值
    borderWidthAnimation.toValue   = [NSNumber numberWithFloat:300.f];

    // 动画持续一次的时间
    borderWidthAnimation.duration    = 0.5f;

    // 选择一种动画的时间轴方式
    borderWidthAnimation.timingFunction = \
        [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];

    // ??
    borderWidthAnimation.fillMode = kCAFillModeForwards;

    // 开始动画
    [_showView.layer addAnimation:borderWidthAnimation forKey:@"bounds.size.height"];

    // 无论动画是否被中断,其最终的值还是被设置过了
    _showView.layer.bounds = CGRectMake(self.view.center.x, self.view.center.y, 20, 300.f);

contents动画

// 初始化一张图片
    UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 100, 100)];
    imageView.image = [UIImage imageNamed:@"1"];

    // 添加进view中
    [self.view addSubview:imageView];

    // contents动画
    CABasicAnimation *crossFade = [CABasicAnimation animationWithKeyPath:@"contents"];

    crossFade.duration = 2.0;
    crossFade.fromValue  = (id)([UIImage imageNamed:@"1"].CGImage);
    crossFade.toValue    = (id)([UIImage imageNamed:@"2"].CGImage);

    [imageView.layer addAnimation:crossFade forKey:@"animateContents"];

    // 进行最后的设置
    imageView.image = [UIImage imageNamed:@"2"];

圆角动画

// 初始化一张图片
    UIView *showView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 100, 100)];
    showView.backgroundColor = [UIColor redColor];
    [self.view addSubview:showView];

    // 圆角动画
    CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"cornerRadius"];

    animation.fromValue = [NSNumber numberWithFloat:0.f];
    animation.toValue   = [NSNumber numberWithFloat:30.f];
    animation.duration  = 1.0;
    [showView.layer setCornerRadius:30.f];

    // 最后设置
    [showView.layer addAnimation:animation forKey:@"cornerRadius"];

支持的动画太多了,以下是苹果的官方文档中提出的支持的动画:

http://www.cnblogs.com/pengyingh/articles/2379631.html