像iOS指南针一样在指南针内旋转UIImageView

Question

我想在我的应用程序中包含一个指南针和标签，重力旋转并保持其作为iOS应用程序指南针的位置。

我已经完成了一些代码并单独运行，但是当它们一起工作时会变得疯狂。

这是我使用的代码的一部分：

UIImageView * imgCompass; UIImageView * north;

- (void)viewDidLoad
{
    [super viewDidLoad];

locationManager = [[CLLocationManager alloc] init];
locationManager.delegate = self;
locationManager.desiredAccuracy = kCLLocationAccuracyBestForNavigation;
locationManager.distanceFilter = kCLDistanceFilterNone;
locationManager.headingFilter = 1;
[locationManager requestWhenInUseAuthorization];
[locationManager startUpdatingLocation];
[locationManager startUpdatingHeading];

motionManager = [[CMMotionManager alloc] init];
motionManager.accelerometerUpdateInterval = 0.01;
motionManager.gyroUpdateInterval = 0.01;

[motionManager startAccelerometerUpdatesToQueue:[NSOperationQueue currentQueue]
                                    withHandler:^(CMAccelerometerData  *accelerometerData, NSError *error) {
                                        if (!error) {
                                            [self outputAccelertionData:accelerometerData.acceleration];
                                        }
                                        else{
                                            NSLog(@"%@", error);
                                        }
                                    }];
}

- (void)locationManager:(CLLocationManager *)manager didUpdateHeading:(CLHeading *)newHeading {

    // Convert Degree to Radian and move the needle
    newRad =  -newHeading.trueHeading * M_PI / 180.0f;

    [UIView animateWithDuration:0.2 delay:0 options:UIViewAnimationOptionCurveEaseInOut animations:^{
        self.viewCompass.transform = CGAffineTransformMakeRotation(newRad);

    } completion:nil];
}


- (void)outputAccelertionData:(CMAcceleration)acceleration{
    //UIInterfaceOrientation orientationNew;

    // Get the current device angle
    float xx = -acceleration.x;
    float yy = acceleration.y;
    float angle = atan2(yy, xx);


    [UIView animateWithDuration:0.2 delay:0 options:UIViewAnimationOptionCurveEaseOut animations:^{
        // Add 1.5 to the angle to keep the image constantly horizontal to the viewer.
        [self.north setTransform:CGAffineTransformMakeRotation(angle - 1.5)];
    } completion:nil];


}

有什么想法吗？谢谢。我很绝望......

Answer 1

我解决了。只需减去罗盘的半径，然后将结果添加到所需的对象中。在我的情况下，北，东，西和南都是UIImageView。

 - (void)locationManager:(CLLocationManager *)manager didUpdateHeading:(CLHeading *)newHeading {
    self.lblGrados.text = [NSString stringWithFormat:@"%.0f°", newHeading.magneticHeading];

    // Convert Degree to Radian and move the needle
    newRad =  -newHeading.trueHeading * M_PI / 180.0f;

    [UIView animateWithDuration:0.6 delay:0 options:UIViewAnimationOptionCurveEaseInOut animations:^{
        compassView.transform = CGAffineTransformMakeRotation(newRad);
    } completion:nil];

    [UIView animateWithDuration:0.6 delay:0 options:UIViewAnimationOptionCurveEaseOut animations:^{
        [self.north setTransform:CGAffineTransformMakeRotation(-newRad)];
        [self.south setTransform:CGAffineTransformMakeRotation(-newRad)];
        [self.east setTransform:CGAffineTransformMakeRotation(-newRad)];
        [self.west setTransform:CGAffineTransformMakeRotation(-newRad)];
    } completion:nil];
}