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];
}