核心动画(基础动画)-转

一.简单介绍   CAPropertyAnimation的子类 

属性解析: 

fromValue：keyPath相应属性的初始值 
toValue：keyPath相应属性的结束值 
　　随着动画的进行，在长度为duration的持续时间内，keyPath相应属性的值从fromValue渐渐的变为toValue。 
　　如果 fillMode=kCAFillModeForwards和removedOnComletion=NO，那么在动画执行完毕后，图层会保持显示动画执行后的状态。但在实质上，图层的属性值还是动画执行前的初始值，并没有真正被改变。 
　　比如，CALayer的position初始值为(0,0)，CABasicAnimation的fromValue为(10,10)，toValue为(100,100)，虽然动画执行完毕后图层保持在(100,100)这个位置，实质上图层的position还是为(0,0)。

二.平移动画

#import "ViewController.h"

@interface ViewController ()
@property(nonatomic,strong) CALayer *myLayer;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    //创建layer
    CALayer *layer = [CALayer layer];
    //设置layer属性
    layer.bounds = CGRectMake(0, 0, 50, 80);
    layer.backgroundColor = [UIColor yellowColor].CGColor;
    layer.position = CGPointMake(50, 50);
    layer.anchorPoint = CGPointMake(0, 0);
    layer.cornerRadius = 20;
    //添加layer
    [self.view.layer addSublayer:layer];
    _myLayer = layer;
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

//设置动画(基础动画)
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
    //创建核心动画
    CABasicAnimation *animation = [CABasicAnimation animation];

    //告诉系统要执行什么的动画
    animation.keyPath = @"position";
    //设置通过动画，将layer从哪儿移动到哪儿
    animation.fromValue = [NSValue valueWithCGPoint:CGPointMake(0, 0)];
    animation.toValue = [NSValue valueWithCGPoint:CGPointMake(200, 300)];

    //设置动画执行完毕之后不删除动画
    animation.removedOnCompletion = NO;
    //设置保持动画的最新状态
    animation.fillMode = kCAFillModeForwards;

    //添加核心动画到layer
    [self.myLayer addAnimation:animation forKey:nil];
}

@end

　　说明: byValue和toValue的区别，前者是在当前的位置上增加多少，后者是到指定的位置。 设置代理：设置动画的代理，可以监听动画的执行过程，这里设置控制器为代理。 

#import <QuartzCore/QuartzCore.h>
@interface ViewController ()<CAAnimationDelegate>
@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    //创建layer
    CALayer *layer = [CALayer layer];
    //设置layer的属性
    layer.bounds = CGRectMake(0, 0, 50, 80);
    layer.backgroundColor = [UIColor yellowColor].CGColor;
    layer.position = CGPointMake(50, 50);
    layer.anchorPoint = CGPointMake(0, 0);
    layer.cornerRadius = 20;
    //添加layer
    [self.view.layer addSublayer:layer];
    self.myLayer = layer;
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

//设置动画(基础动画)
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
    //创建核心动画
    CABasicAnimation *animation = [CABasicAnimation animation];
    //告诉系统要执行什么样的动画
    animation.keyPath = @"position";
    //设置通过动画,将layer从哪儿移动到哪儿
    animation.fromValue = [NSValue valueWithCGPoint:CGPointMake(0, 0)];
    animation.toValue = [NSValue valueWithCGPoint:CGPointMake(200, 300)];
    //设置动画执行完毕之后不删除动画
    animation.removedOnCompletion = NO;
    //设置保持动画的最新状态
    animation.fillMode = kCAFillModeForwards;
    animation.delegate = self;
    //打印
    NSString *str = NSStringFromCGPoint(self.myLayer.position);
    NSLog(@"执行前:%@",str);
    //添加核心动画到layer
    [_myLayer addAnimation:animation forKey:nil];
}

#pragma mark -Core Animation Delegate
- (void)animationDidStart:(CAAnimation *)anim{
    NSLog(@"开始执行动画");
}

- (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag{
    //动画执行完毕，打印执行完毕后的position值
    NSString *str = NSStringFromCGPoint(_myLayer.position);
    NSLog(@"执行后:%@",str);
}

@end

　　通过打印结构可以看出，属性值还是动画执行前的初始值{50,50}，并没有真正被改变为{200,300}。

三.缩放动画

#import "ViewController.h"
@interface ViewController ()
@property(nonatomic,strong) CALayer *myLayer;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    //创建layer
    CALayer *layer = [CALayer layer];
    //设置layer的属性
    layer.bounds = CGRectMake(0, 0, 50, 80);
    layer.backgroundColor = [UIColor yellowColor].CGColor;
    layer.position = CGPointMake(50, 50);
    layer.anchorPoint = CGPointMake(0, 0);
    layer.cornerRadius = 20;
    //添加layer
    [self.view.layer addSublayer:layer];
    self.myLayer = layer;
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

//设置动画(基础动画)
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
    //创建动画
    CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"bounds"];
    //设置动画执行时间
    animation.duration = 2.0;
    //设置动画执行完毕后不删除动画
    animation.removedOnCompletion = NO;
    //设置保持动画的最新状态
    animation.fillMode = kCAFillModeForwards;
    //修改属性，执行动画
    animation.toValue = [NSValue valueWithCGRect:CGRectMake(0, 0, 200, 200)];
    //添加动画到layer
    [_myLayer addAnimation:animation forKey:nil];
}

#pragma mark -Core Animation Delegate
- (void)animationDidStart:(CAAnimation *)anim{
}

- (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag{
}

@end

四.旋转动画

#import "ViewController.h"
@interface ViewController ()
@property(nonatomic,strong) CALayer *myLayer;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    //创建layer
    CALayer *layer = [CALayer layer];
    //设置layer的属性
    layer.bounds = CGRectMake(0, 0, 50, 80);
    layer.backgroundColor = [UIColor yellowColor].CGColor;
    layer.position = CGPointMake(50, 50);
    layer.anchorPoint = CGPointMake(0, 0);
    layer.cornerRadius = 20;
    //添加layer
    [self.view.layer addSublayer:layer];
    self.myLayer = layer;
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

//设置动画(基础动画)
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
    //创建动画
    CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform"];
    //设置动画执行时间
    animation.duration = 2.0;
    //设置动画执行完毕后不删除动画
    animation.removedOnCompletion = NO;
    //设置保持动画的最新状态
    animation.fillMode = kCAFillModeForwards;
    //修改属性，执行动画
    animation.toValue = [NSValue valueWithCATransform3D:CATransform3DMakeRotation(M_PI_2+M_PI_4, 1, 1, 0)];
    //添加动画到layer
    [_myLayer addAnimation:animation forKey:nil];
}

#pragma mark -Core Animation Delegate
- (void)animationDidStart:(CAAnimation *)anim{}

- (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag{}

@end

　　提示：如果要让图形以2D的方式旋转，只需要把CATransform3DMakeRotation在z方向上的值改为1即可。

五.补充 
　　可以通过transform (KVC)的方式来进行设置

@interface ViewController ()
@property(nonatomic,strong) CALayer *myLayer;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    //创建layer
    CALayer *layer = [CALayer layer];
    //设置layer的属性
    layer.bounds = CGRectMake(0, 0, 50, 80);
    layer.backgroundColor = [UIColor yellowColor].CGColor;
    layer.position = CGPointMake(50, 50);
    layer.anchorPoint = CGPointMake(0, 0);
    layer.cornerRadius = 20;
    //添加layer
    [self.view.layer addSublayer:layer];
    self.myLayer = layer;
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

//设置动画(基础动画)
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
    //创建动画
    CABasicAnimation *animation = [CABasicAnimation animation];
    animation.keyPath = @"transform";
    //设置动画执行时间
    animation.duration = 2.0;
    //设置动画执行完毕后不删除动画
    animation.removedOnCompletion = NO;
    //设置保持动画的最新状态
    animation.fillMode = kCAFillModeForwards;
    //修改属性，执行动画
    animation.toValue = [NSValue valueWithCATransform3D:CATransform3DMakeTranslation(0, 100, 1)];
    //添加动画到layer
    [_myLayer addAnimation:animation forKey:nil];
}

#pragma mark -Core Animation Delegate
- (void)animationDidStart:(CAAnimation *)anim{}

- (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag{}

@end