iOS - 闪关灯

- (void)turnTorchOn:(BOOL)on

{

//    lockForConfiguration跟unlockForConfiguration是配对的API

//    呼叫lockForConfiguration就可以控制硬件了

//    控制完毕后要呼叫unlockForConfiguration

    Class captureDeviceClass = NSClassFromString(@"AVCaptureDevice");

    if (captureDeviceClass !=
nil) {

        AVCaptureDevice *device = [AVCaptureDevice
defaultDeviceWithMediaType:AVMediaTypeVideo];

        if ([device
hasTorch] && [device hasFlash]) {

            [device lockForConfiguration:nil];

            if (on) {

                [device setTorchMode:AVCaptureTorchModeOn];

                [device setFlashMode:AVCaptureFlashModeOn];

            } else {

                [device setTorchMode:AVCaptureTorchModeOff];

                [device setFlashMode:AVCaptureFlashModeOff];

            }

            [device unlockForConfiguration];

        }

    }

}