iOS CAKeyframeAnimation

//代理方法
- (void)animationDidStart:(CAAnimation *)anim；
- (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag；

//eg. move
- (void)testMove
{
CAKeyframeAnimation *anim = [CAKeyframeAnimation animation];

anim.keyPath = @"position";

NSValue *v1 = [NSValue valueWithCGPoint:CGPointZero];
NSValue *v2 = [NSValue valueWithCGPoint:CGPointMake(100, 0)];
NSValue *v3 = [NSValue valueWithCGPoint:CGPointMake(100, 200)];
NSValue *v4 = [NSValue valueWithCGPoint:CGPointMake(0, 200)];
anim.values = @[v1, v2, v3, v4];

//控制每个动画的时间
//    anim.keyTimes = @[@(0.5), @(0.25), @(0.25)];

anim.duration = 2.0;

anim.removedOnCompletion = NO;
anim.fillMode = kCAFillModeForwards;

[self.redView.layer addAnimation:anim forKey:nil];
}

//eg. circle
- (void)testCircle
{
CAKeyframeAnimation *anim = [CAKeyframeAnimation animation];

anim.keyPath = @"position";
anim.removedOnCompletion = NO;
anim.fillMode = kCAFillModeForwards;
anim.duration = 3.0;

CGMutablePathRef path = CGPathCreateMutable();
//圆形动画
CGPathAddEllipseInRect(path, NULL, CGRectMake(100, 100, 200, 200));
anim.path = path;
CGPathRelease(path);

// 设置动画的执行节奏
anim.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
anim.delegate = self;

[self.redView.layer addAnimation:anim forKey:nil];
}