关于 Core Animation

Core Animation是一组非常强大的动画处理API,使用它能做出很多优雅的动画效果。能用的动画类有4个子类：CABasicAnimation、CAKeyframeAnimation、CATransition、CAAnimationGroup

开发步骤:

1. 初始化一个动画对象(CAAnimation)并设置一些动画相关属性.

2. 添加动画对象到层(CALayer)中,开始执行动画.

CALayer中很多属性都可以通过CAAnimation实现动画效果, 包括opacity, position, transform, bounds, contents等，具体可以在API文档中查找

通过调用CALayer的addAnimation:forKey:增加动画到层(CALayer)中,这样就能触发动画了.通过调用removeAnimationForKey:可以停止层中的动画.

注：Core Animation的动画执行过程都是在后台操作的,不会阻塞主线程.

创建动画时你可能用到的属性

巧妙的运用这些可以属性实现很棒的动画效果，比如下面：用CABasicAnimation实现的动画

CABasicAnimation动画

简单的呼吸和摇摆动画

animation.gif

简单的代码

 1.呼吸动画
    CABasicAnimation *animation =[CABasicAnimation animationWithKeyPath:@"opacity"];
    animation.fromValue = [NSNumber numberWithFloat:1.0f];
    animation.toValue = [NSNumber numberWithFloat:0.0f];
    animation.autoreverses = YES;    //回退动画（动画可逆，即循环）
    animation.duration = 1.0f;
    animation.repeatCount = MAXFLOAT;
    animation.removedOnCompletion = NO;
    animation.fillMode = kCAFillModeForwards;//removedOnCompletion,fillMode配合使用保持动画完成效果
    animation.timingFunction=[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
    [self.alphaTagButton.layer addAnimation:animation forKey:@"aAlpha"];  

2.摇摆动画
    //设置旋转原点
    self.sharkTagButton.layer.anchorPoint = CGPointMake(0.5, 0);
    CABasicAnimation* rotationAnimation = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];
    //角度转弧度（这里用1，-1简单处理一下）
    rotationAnimation.toValue = [NSNumber numberWithFloat:1];
    rotationAnimation.fromValue = [NSNumber numberWithFloat:-1];
    rotationAnimation.duration = 1.0f;
    rotationAnimation.repeatCount = MAXFLOAT;
    rotationAnimation.removedOnCompletion = NO;
    rotationAnimation.autoreverses = YES;
    rotationAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
    rotationAnimation.fillMode = kCAFillModeForwards;
    [self.sharkTagButton.layer addAnimation:rotationAnimation forKey:@"revItUpAnimation"];

陀螺仪&加速仪的动画

ps:好吧 这个属于乱入，和上面的摇摆动画差不多的效果，只是这个是手动的 哈哈

3、陀螺仪&加速仪的动画
    self.motionManager = [[CMMotionManager alloc] init];
    self.motionManager.deviceMotionUpdateInterval = 1.0f/100.0f; //1秒100次
    self.sharkTagButton.layer.anchorPoint = CGPointMake(0.5, 0);
    [self.motionManager startDeviceMotionUpdatesToQueue:[NSOperationQueue currentQueue] withHandler:^(CMDeviceMotion *motion, NSError *error) {
        if(fabs(motion.attitude.roll)<1.0f)
        {
            [UIView animateWithDuration:0.6 animations:^{
                self.sharkTagButton.layer.transform = CATransform3DMakeRotation(-(motion.attitude.roll), 0, 0, 1);
            }];
        }else if (fabs(motion.attitude.roll)<1.5f)
        {
            [UIView animateWithDuration:0.6 animations:^{
                int s;
                if (motion.attitude.roll>0)
                {
                    s=-1;
                }else
                {
                    s = 1;
                }
                self.sharkTagButton.layer.transform = CATransform3DMakeRotation(s*M_PI_2, 0, 0, 1);
            }];
        }
        if ((motion.attitude.pitch)<0)
        {
            [UIView animateWithDuration:0.6 animations:^{
                self.sharkTagButton.layer.transform = CATransform3DMakeRotation(M_PI, 0, 0, 1);
            }];
        }

    }];

Demo地址：
https://github.com/yongliangP/CABasicAnimationDemo

CATransition之简单的转场动画

CAAnimation的子类，用于做转场动画，能够为层提供移出屏幕和移入屏幕的动画效果。

• 常用动画类型:

注：私有API只能通过字符串使用哈

• 过渡方向参数:

简单的CATransition动画

CATransitionDemo2.gif

-(void)animationWithType:(NSString*)type
{

    //- 创建一个转场动画:
    CATransition *transition = [CATransition animation];
    transition.repeatCount = 5;

    //    - 确定动画类型:
    transition.type = type;

    //    - 确定子类型(方向等)
    transition.subtype = kCATransitionFromLeft;

    //    - 确定动画时间
    transition.duration = 1;

    //    - 添加动画
    [self.imageView.layer addAnimation:transition forKey:nil];

}

使用时只用传你的想要的动画类型就好，私有API只能通过字符串使用哈。

[self animationWithType:self.dataArray[indexPath.row]];

DEMO地址：https://github.com/yongliangP/CATransitionDemo

---20160908更新

CAKeyframeAnimation

先看图，就是那个在跑的小圆球，为了方便，把动画集成在了一个Demo里了

ScreenShotDemo2.gif

• 1 .简单介绍

  CAKeyframeAnimation是CApropertyAnimation的子类，跟CABasicAnimation的区别是：CABasicAnimation只能从一个数值(fromValue)变到另一个数值(toValue)，而CAKeyframeAnimation会使用一个NSArray保存这些数值，是一种更灵活的动画方式。

• 2 .属性介绍

• 3 .实现
  • 3.1 values方式实现

-(void)setUpCAKeyframeAnimationUseValues
{

    CAKeyframeAnimation *animation = [CAKeyframeAnimation animation];

    animation.keyPath = @"position";

    NSValue *value1 = [NSValue valueWithCGPoint:CGPointMake(50, 50)];

    NSValue *value2 = [NSValue valueWithCGPoint:CGPointMake(kWindowWidth - 50, 50)];

    NSValue *value3 = [NSValue valueWithCGPoint:CGPointMake(kWindowWidth - 50, kWindowHeight-50)];

    NSValue *value4 = [NSValue valueWithCGPoint:CGPointMake(50, kWindowHeight-50)];

    NSValue *value5 = [NSValue valueWithCGPoint:CGPointMake(50, 50)];

    animation.values = @[value1,value2,value3,value4,value5];
    animation.repeatCount = MAXFLOAT;

    animation.removedOnCompletion = NO;

    animation.fillMode = kCAFillModeForwards;

    animation.duration = 6.0f;

    animation.timingFunction=[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];

    [self.keyButton.layer addAnimation:animation forKey:@"values"];

}

• • 3.2 path方式实现

-(void)setUpCAKeyframeAnimationUsePath
{
    CAKeyframeAnimation *animation = [CAKeyframeAnimation animation];

    animation.keyPath = @"position";

    CGMutablePathRef path = CGPathCreateMutable();

    //矩形线路
    CGPathAddRect(path, NULL, CGRectMake(50,50, kWindowWidth - 100,kWindowHeight - 100));

    animation.path=path;

    CGPathRelease(path);

    animation.repeatCount = MAXFLOAT;

    animation.removedOnCompletion = NO;

    animation.fillMode = kCAFillModeForwards;

    animation.duration = 10.0f;

    animation.timingFunction=[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];

    [self.keyButton.layer addAnimation:animation forKey:@"path"];


}

• • 3.3 keyTimes演示

-(void)setUpCAKeyframeAnimationUsekeyTimes
{

    CAKeyframeAnimation *animation = [CAKeyframeAnimation animation];
//    animation.keyPath = @"transform.translation.x";
    animation.keyPath = @"position.x";
    animation.values = @[@0, @20, @-20, @20, @0];
    animation.keyTimes = @[ @0, @(1 / 6.0), @(3 / 6.0), @(5 / 6.0), @1 ];
    animation.duration = 0.5;
    animation.additive = YES;
    [self.sharkTagButton.layer addAnimation:animation forKey:@"keyTimes"];

}

附：关于keyPath你可能用到的属性

照例放Demo
Demo地址：
https://github.com/yongliangP/CABasicAnimationDemo

作者：iceMaple

原文链接：http://www.jianshu.com/p/a098f6e3617f