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:
Property |
Default animation |
---|---|
Uses the default implied |
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Uses the default implied |
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Uses the default implied |
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Uses the default implied |
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Uses the default implied |
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Uses the default implied |
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Uses the default implied |
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Uses the default implied |
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Uses the default implied |
|
Uses the default implied |
|
There is no default implied animation. |
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Uses the default implied |
|
This property is not animatable. You can achieve the same results by animating the |
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Uses the default implied |
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Uses the default implied |
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Uses the default implied |
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Uses the default implied |
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Uses the default implied |
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Uses the default implied |
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Uses the default implied |
|
Uses the default implied |
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Uses the default implied |
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Uses the default implied |
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Uses the default implied |
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Uses the default implied |
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Uses the default implied |
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Uses the default implied |