objective-c - 确定 iPhone 何时平放

Question

是否有办法确定 iPhone 何时处于背面放置状态？

这是在一个表面上，或者用户将其握在手中，然后移动手机，使其平放在半空中。

我知道 iPhone 有陀螺仪和加速计，但我不确定如何使用它们来找出这一点。

Answer 1

看看UIDeviceOrientation :

typedef NS_ENUM(NSInteger, UIDeviceOrientation) {
    UIDeviceOrientationUnknown,
    UIDeviceOrientationPortrait,            // Device oriented vertically, home button on the bottom
    UIDeviceOrientationPortraitUpsideDown,  // Device oriented vertically, home button on the top
    UIDeviceOrientationLandscapeLeft,       // Device oriented horizontally, home button on the right
    UIDeviceOrientationLandscapeRight,      // Device oriented horizontally, home button on the left
    UIDeviceOrientationFaceUp,              // Device oriented flat, face up
    UIDeviceOrientationFaceDown             // Device oriented flat, face down
};