檢測設備攝像頭、指南針、錄音、陀螺儀狀態的iOS代碼

//檢查前后攝像頭
BOOL cameraAvailable = [UIImagePickerController isCameraDeviceAvailable:UIImagePickerControllerCameraDeviceRear];//前
BOOL frontCameraAvailable = [UIImagePickerController isCameraDeviceAvailable:UIImagePickerControllerCameraDeviceFront];//后

//檢查指南針 CoreLocation.framework  <CoreLocation/CoreLocation.h>
BOOL magnetometerAvailbale = [CLLocationManager headingAvailable];
//檢查聲音支持 AVFoundation.framework <AVFoundation/AVFoundation.h>
AVAudioSession *audioSession = [AVAudioSession sharedInstance];  //返回一個AVAudioSession實例
BOOL audioAvailable = audioSession.inputAvailable;//bool值。獲取是否支持
//檢查錄像支持 MobileCoreServices.framework <MobileCoreServices/MobileCoreServices.h>

(BOOL)isvideoCameraAvailable
{
  //簡單檢查所有的可用的媒體資源類型，然后檢查返回的數組，如果其中包含了kUTTypeMovie的NSString類型對象，就證明攝像頭支持錄像
  UIImagePickerController picker = [[UIImagePickerController alloc]init];
  NSArray sourceTypes = [UIImagePickerController availableMediaTypesForSourceType:picker.sourceType];//返回所支持的media的類型數組
  [picker release];
if (![sourceTypes containsObject:(NSString *)kUTTypeMovie]) {//containsObject確定數組中是否包含后面的對象

  return NO;

}
  return YES;
}


//檢查陀螺儀可用 CoreMotion.framework <CoreMotion/CoreMotion.h>

(BOOL) isGyroscopeAvailable
{
#ifdef __IPHONE_4_0//4.0之后才有
  CMMotionManager *motionManager = [[CMMotionManager alloc]init];
  BOOL gyroscopeAvailable = motionManager.gyroAvailable;
  [motionManager release];
  return gyroscopeAvailable;
#else
  return NO;
#endif
}</pre>