ios - 相机处于横向模式

Question

我正在使用 AVFoundation 框架来管理相机。当我处于横向模式时，我希望将拍摄按钮保持在屏幕右侧，如下图所示:

知道怎么做吗？

Answer 1

这是我的解决方案。

1) 禁用自动旋转，(我假设你不想旋转整个 View )

2) 将您的 View Controller 注册为 UIDeviceOrientationDidChangeNotification 的观察者

- (void)viewDidLoad {
    ...
    NSNotificationCenter *notificationCenter = [NSNotificationCenter defaultCenter];
    [notificationCenter addObserver:self selector:@selector(deviceOrientationDidChange) name:UIDeviceOrientationDidChangeNotification object:nil];
    [[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
    ...
}

并确保在释放观察者对象之前调用 removeObserver。

- (void)dealloc {
    [[NSNotificationCenter defaultCenter] removeObserver:self name:UIDeviceOrientationDidChangeNotification object:nil];
}

3) 处理方向变化

- (void)deviceOrientationDidChange {
    UIDeviceOrientation orientation = [[UIDevice currentDevice] orientation];
    switch (orientation) {
        case UIDeviceOrientationPortrait:
        {
            [self rotateInterfaceWithDegrees:0.0];
        }
            break;
        case UIDeviceOrientationPortraitUpsideDown:
        {
            [self rotateInterfaceWithDegrees:180.0];
        }
            break;
        case UIDeviceOrientationLandscapeLeft:
        {
            [self rotateInterfaceWithDegrees:90.0];
        }
            break;
        case UIDeviceOrientationLandscapeRight:
        {
            [self rotateInterfaceWithDegrees:270.0];
        }
            break;

        default:
            break;
    }
}

4) 进行旋转变换并应用到你的按钮上

- (void)rotateInterfaceWithDegrees:(NSUInteger)degrees {
    CGAffineTransform transform = CGAffineTransformMakeRotation(degrees*M_PI/180.0);
    [UIView animateWithDuration:0.3   // with animation
                     animations:^{    // optional
                         yourFirstButton.transform = transform;
                         yourSecondButton.transform = transform;
                         ...
                     }];
}

希望对您有所帮助。