如何在ios7中检测旋转时的横向模式？

Question

我的应用程序显示pdf页面，在纵向模式下显示单个页面（默认模式为纵向）。在旋转到landcscape时，它应该并排显示两页， 在我的ViewController的viewdidloadmethod中添加了以下内容，

  - (void)viewDidLoad
{

        UIDeviceOrientation deviceOrientation = [[UIDevice currentDevice] orientation];
        landscape=UIDeviceOrientationIsLandscape(deviceOrientation);
    if(landscape)
    {
      //logic goes here
    }
    else
    {
     logic for portrait goes here
    }
}

但这对我不起作用，只有肖像逻辑得到了规范。请帮助

Answer 1

方向更改的处理方式略有不同。 当方向发生变化时，您的viewcontroller需要接收通知。

以下是示例代码：

@implementation PortraitViewController
- (void)awakeFromNib
{
    isShowingLandscapeView = NO;
    [[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
    [[NSNotificationCenter defaultCenter] addObserver:self
                                 selector:@selector(orientationChanged:)
                                 name:UIDeviceOrientationDidChangeNotification
                                 object:nil];
}

- (void)orientationChanged:(NSNotification *)notification
{
    UIDeviceOrientation deviceOrientation = [UIDevice currentDevice].orientation;
    if (UIDeviceOrientationIsLandscape(deviceOrientation) &&
        !isShowingLandscapeView)
    {
        isShowingLandscapeView = YES;
        // logic for landscape orientation goes here
    }
    else if (UIDeviceOrientationIsPortrait(deviceOrientation) &&
             isShowingLandscapeView)
    {
        isShowingLandscapeView = NO;
        // logic for portrait orientation goes here
    }
}

有关更多信息，请查看Apple documentation