我希望将IBOutlet围绕父视图中的特定点旋转,目前我只知道如何围绕锚点旋转它,但是我想使用对象层外的点。
旋转角度相对于该点从设备方向计算而来。
- (void)viewDidLoad{
[super viewDidLoad];
locationManager=[[CLLocationManager alloc] init];
locationManager.desiredAccuracy = kCLLocationAccuracyBest;
locationManager.headingFilter = 1;
locationManager.delegate=self;
[locationManager startUpdatingHeading];
[locationManager startUpdatingLocation];
compassImage.layer.anchorPoint=CGPointZero;
}
- (void)locationManager:(CLLocationManager *)manager didUpdateHeading:(CLHeading *)newHeading{
// Convert Degree to Radian and move the needle
float oldRad = -manager.heading.trueHeading * M_PI / 180.0f;
float newRad = -newHeading.trueHeading * M_PI / 180.0f;
CABasicAnimation *theAnimation;
theAnimation=[CABasicAnimation animationWithKeyPath:@"transform.rotation"];
theAnimation.fromValue = [NSNumber numberWithFloat:oldRad];
theAnimation.toValue=[NSNumber numberWithFloat:newRad];
theAnimation.duration = 0.5f;
[compassImage.layer addAnimation:theAnimation forKey:@"animateMyRotation"];
compassImage.transform = CGAffineTransformMakeRotation(newRad);
NSLog(@"%f (%f) => %f (%f)", manager.heading.trueHeading, oldRad, newHeading.trueHeading, newRad);
}
如何使UIImageView绕(x,y)旋转alpha度?