如何在旋转前检测iPhone方向 [英] how do I detect the iPhone orientation before rotating

问题描述

在我的程序中，我根据旋转移动的东西，但我不旋转整个视图。我正在使用：

In my program I'm moving things based on rotation, but I'm not rotating the entire view. I'm Using :

  static UIDeviceOrientation previousOrientation = UIDeviceOrientationPortrait;

 - (void)applicationDidFinishLaunching:(UIApplication *)application {   
    [window addSubview:viewController.view];
    [window makeKeyAndVisible];
    [[NSNotificationCenter defaultCenter] addObserver:self
           selector:@selector(didRotate:)
           name:@"UIDeviceOrientationDidChangeNotification" object:nil];

}

- (void) didRotate:(NSNotification *)notification{  
UIDeviceOrientation orientation = [[UIDevice currentDevice] orientation];

    [self doRotationStuff:orientation: previousOrientation];
previousOrientation = orientation;

} 

只要启动程序，设备方向是纵向，但如果初始方向是横向或倒置，则不是，因为[self doRotationStuff]相对于与先前方向的差异进行更改。

This works as long as, when the program is launched, the device orientation is portrait, but not if the initial orientation is landscape or upside down, because [self doRotationStuff] makes changes relative to the difference from the previous orientation.

有一种方法可以在启动时或在设备旋转之前检测方向。

Is there a way to detect the orientation either at launch, or right before the device is rotated?

推荐答案

根据您的情况，更简单的选项可以是UIViewController类的interfaceOrientation属性。这在旋转之前是正确的。

Depending on your circumstances, a simpler option may be the interfaceOrientation property of the UIViewController class. This is correct before a rotation.

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