线性动画。 初始化动画对象：     _imageView = [[UIImageView alloc]init];     [_imageView setBackgroundColor:[UIColor clearColor]];     [_imageView setFrame:CGRectMake(20, 40, 20, 60)];     [_imageView setI

1.书写动画代码，设置参数。 CAKeyframeAnimation * mover = [CAKeyframeAnimation animationWithKeyPath:@"position"];     NSMutableArray * val = [NSMutableArray array];     [val addObject:[NSValue valueWithCGP

有个很关键的属性：rotationMode // 把rotationMode设置=kCAAnimationRotateAuto根据曲线的切线自动旋转     keyframeAnimation.rotationMode =kCAAnimationRotateAuto ; //// ViewController.m// CAKeyframeAnimation--+CAS

//关键帧动画 CAKeyframeAnimation- (void)keyAnimation{CALayer *layer =[CALayer layer];layer.bounds = CGRectMake(0, 0, 100, 100);layer.position = CGPointMake(100,100);layer.backgroundColor = [UIColor yellow