core Animation之CAKeyframeAnimation(关键帧动画)

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

属性解析：

values：就是上述的NSArray对象。里面的元素称为”关键帧”(keyframe)。动画对象会在指定的时间(duration)内，依次显示values数组中的每一个关键帧

path：可以设置一个CGPathRef\CGMutablePathRef,让层跟着路径移动。path只对CALayer的anchorPoint和position起作用。如果你设置了path，那么values将被忽略

keyTimes：可以为对应的关键帧指定对应的时间点,其取值范围为0到1.0,keyTimes中的每一个时间值都对应values中的每一帧.当keyTimes没有设置的时候,各个关键帧的时间是平分的

说明：CABasicAnimation可看做是最多只有2个关键帧的CAKeyframeAnimation

#import "ViewController.h"
 
@interface ViewController ()
@property(nonatomic,strong)UIButton *btn;
@end
 
@implementation ViewController
 
- (void)viewDidLoad {
    [super viewDidLoad];
    self.btn=[UIButton buttonWithType:UIButtonTypeSystem];
    self.btn.frame=CGRectMake(100, 100, 50, 40);
    [self.btn setTitle:@"按钮" forState:UIControlStateNormal];
    [self.btn addTarget:self action:@selector(btnClick:) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:self.btn];
}
 
-(void)btnClick:(id)sender
{
    //关键帧动画有两种实现方式 一种是通过设置values的值来改变 另一种是通过设置path属性值来改变
     
    //values属性
    CAKeyframeAnimation *keyframeAnimation=[CAKeyframeAnimation animation];
    keyframeAnimation.keyPath=@"position";
    NSValue *value1=[NSValue valueWithCGPoint:CGPointMake(100, 100)];
    NSValue *value2=[NSValue valueWithCGPoint:CGPointMake(200, 100)];
    NSValue *value3=[NSValue valueWithCGPoint:CGPointMake(200, 200)];
    NSValue *value4=[NSValue valueWithCGPoint:CGPointMake(100, 200)];
    NSValue *value5=[NSValue valueWithCGPoint:CGPointMake(100, 100)];
    keyframeAnimation.values=@[value1,value2,value3,value4,value5];
    //values和keyTimes的个数是一样的 值在0-1之间 逐渐增加直到为1
    keyframeAnimation.keyTimes=@[[NSNumber numberWithFloat:0.1],[NSNumber numberWithFloat:0.3],[NSNumber numberWithFloat:0.5],[NSNumber numberWithFloat:0.75],[NSNumber numberWithFloat:1]];
    keyframeAnimation.removedOnCompletion=NO;
    keyframeAnimation.fillMode=kCAFillModeForwards;
    keyframeAnimation.duration=4.0;
    keyframeAnimation.timingFunction=[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
    keyframeAnimation.delegate=self;
    //设置动画的key 这样可以移除动画 [self.btn.layer removeAnimationForKey:<#(NSString *)#>]
    [self.btn.layer addAnimation:keyframeAnimation forKey:@"cuiyw"];
     
     
    //path属性
//    CAKeyframeAnimation *keyframeAnimation=[CAKeyframeAnimation animation];
//    keyframeAnimation.keyPath=@"position";
//    CGMutablePathRef path=CGPathCreateMutable();
//    CGPathAddEllipseInRect(path, NULL, CGRectMake(100, 100, 200, 200));
//    keyframeAnimation.path=path;
//    keyframeAnimation.duration=5.0;
//    //ease 缓解
////    kCAMediaTimingFunctionLinear 线性（匀速）|
////    kCAMediaTimingFunctionEaseIn 先慢|
////    kCAMediaTimingFunctionEaseOut 后慢|
////    kCAMediaTimingFunctionEaseInEaseOut 先慢 后慢 中间快|
////    kCAMediaTimingFunctionDefault 默认
//    keyframeAnimation.timingFunction=[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
//    keyframeAnimation.removedOnCompletion=NO;
//    keyframeAnimation.fillMode=kCAFillModeForwards;
//    
//    [self.btn.layer addAnimation:keyframeAnimation forKey:nil];
//    
     
}
- (void)animationDidStart:(CAAnimation *)anim
{
    NSLog(@"开始动画");
}
- (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag
{
    NSLog(@"结束动画");
 
}
 
- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}
 
@end