在IOS中使用AVCaptureSession打开之前闪烁闪光灯

Question

我有一个场景来打开/关闭iPhone应用程序的闪光灯，这里使用以下代码完美地为我工作，但它在开启之前闪烁一次。这是代码

    AVCaptureSession *session = [[AVCaptureSession alloc] init];

    // Create device input and add to current session
    AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device error: nil];
    [session addInput:input];

    // Create video output and add to current session      
    AVCaptureVideoDataOutput *output = [[AVCaptureVideoDataOutput alloc] init];
    [session addOutput:output];

    // Start session configuration
    [session beginConfiguration];
    [device lockForConfiguration:nil];

    // Set torch to on
    [device setTorchMode:AVCaptureTorchModeOn];
    [device setFlashMode:AVCaptureFlashModeOn];

    [device unlockForConfiguration];
    [session commitConfiguration];

    // Start the session
    [session startRunning];

// Keep the session around
    [self setAVSession:session];

是否可以在开启前处理闪烁。如果有任何想法，请与我分享，这将非常有用。提前谢谢..