闪光灯是否存在
@property(nonatomic, readonly) BOOL hasFlash;
闪光灯是否可用
@property(nonatomic, readonly, getter=isFlashAvailable) BOOL flashAvailable
闪光灯是否活跃中
@property(nonatomic, readonly, getter=isFlashActive) BOOL flashActive
设置闪光灯模式
@property(nonatomic) AVCaptureFlashMode flashMode
- (BOOL)isFlashModeSupported:(AVCaptureFlashMode)flashMode
typedef NS_ENUM(NSInteger, AVCaptureFlashMode) {
AVCaptureFlashModeOff = 0,
AVCaptureFlashModeOn = 1,
AVCaptureFlashModeAuto = 2,
} NS_AVAILABLE(10_7, 4_0) __TVOS_PROHIBITED;
