如何在不使用iPhone中的相機/視頻模式的情況下使用手電筒？

Question

我正在使用以下代碼在iPhone應用程序中打開手電筒燈。 它工作正常。 問題是，當我們按下按鈕時，手電筒模式將變為“開”，但只有當用戶進入相機屏幕時才會出現手電筒燈。 我想在不使用相機屏幕的情況下打開手電筒燈。 有人可以指導我嗎？ 請建議我在哪里錯了。 這是我的代碼，

captureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    if (captureDevice.torchMode == AVCaptureTorchModeOff)  
    {
        AVCaptureSession *session = [[AVCaptureSession alloc] init];
        [session beginConfiguration];

        [captureDevice lockForConfiguration:nil];
        [captureDevice setTorchMode:AVCaptureTorchModeOn];
        [captureDevice unlockForConfiguration];

        [session commitConfiguration];
        [session startRunning];

        [self setTorchSession:session];
        [session release];
    }
    else 
    {
        [torchSession stopRunning];
        [captureDevice setTorchMode:AVCaptureTorchModeOff];
    }

這是iPhone中Torch Light的正確代碼嗎？ 請幫我。 提前致謝。

Answer 1

這段代碼適合我

- (void) internal_setFlashOn: (BOOL) turnOn {
  AVCaptureDevice *theDevice = self.captureDevice;

  if ([theDevice hasTorch]) {
    [theDevice lockForConfiguration: nil];
    AVCaptureTorchMode currentMode = [theDevice torchMode];
    BOOL isAlreadyTurnedOn = (AVCaptureTorchModeOn == currentMode);
    if (isAlreadyTurnedOn != turnOn) {
      [theDevice setTorchMode: turnOn? AVCaptureTorchModeOn: AVCaptureTorchModeOff];
    }

    [theDevice unlockForConfiguration];
  }
}

- (AVCaptureDevice *) captureDevice {
  if (nil == internal_captureDevice) {
    internal_captureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    [internal_captureDevice retain];
  }
  return internal_captureDevice;
}

這適用於iPhone4及更高版本。