旋转CALayer从起始角度

Question

我想使用byValue不断地旋转一个图层，但是我无法正确实现它。我想每秒旋转6度，以便在60秒内完成一次完整的旋转。

如果图层的初始旋转角度为0，则一切正常。

问题出在当我尝试设置一个初始的fromValue时。如果我将fromValue设置为90度，则动画会从90度旋转到90+6度，然后跳到90+(90+6)度，继续动画，然后再次跳跃。

有什么想法吗？

CABasicAnimation* animation = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];

animation.fromValue = [NSNumber numberWithDouble:M_PI_2];
animation.byValue = [NSNumber numberWithDouble:6.0f*M_PI/180.0f];
animation.toValue = nil;

animation.fillMode = kCAFillModeForwards;
animation.cumulative = YES;
animation.additive = NO;
animation.repeatCount = 10000;
animation.removedOnCompletion = YES;
animation.duration = 1.0;
[myLayer addAnimation:animation forKey:@"transform"];

- Stephan Burlot

Answer 1

这对我有效：

CABasicAnimation* animation = [CABasicAnimation animationWithKeyPath: @"transform"];
CATransform3D transform = CATransform3DMakeRotation (DegreesToRadians (90), 0, 0, 1);
animation.toValue = [NSValue valueWithCATransform3D: transform];
animation.duration = 60;
animation.cumulative = NO;
animation.repeatCount = 10000;
animation.removedOnCompletion = YES;

- fabrice truillot de chambrier