how to turn on camera flash light or torch light using qt?

Question

I need to know how to turn on camera flash light or torch light using qt ? Is there any way to do this ? I am using qt 5.5. Please give suggestion.

Here is My code

#include "flashon.h"

FlashOn::FlashOn()
{
    cam = new QCamera;
    camExpos = cam->exposure ();
}

FlashOn::~FlashOn()
{
    delete this;
}

void FlashOn::lightOn()
{
    camExpos->setFlashMode (QCameraExposure::FlashOn);
    qDebug() << " light is on ";
}

Answer 1

Well, if you read the documentation, there's QCameraExposure::FlashTorch in QCameraExposure::FlashModes.

camExpos->setFlashMode(QCameraExposure::FlashTorch);

All devices may not support it:

QCameraExposure::FlashTorch - 0x20 - Constant light source. If supported, torch can be enabled without loading the camera.

So you probably want to check to see if it is available:

if (!camExpos->isFlashModeSupported(QCameraExposure::FlashTorch)) {
    // ...not supported...
}