I have two webcams, but QCameraInfo::availableCameras returns empty array

问题

According to the documentation, QCameraInfo::availableCameras should return list of available cameras. There's no catch to it according to the docs.

But still, I have two webcams and the array of available cameras is returned empty. What can I do? Is this even in the scope of programming, or does this mean Qt only supports limited subset of webcams?

The OS I'm using right now is Windows 7x64.

回答1:

I have this Problem too.Then I read about the example. I found that once you have declared QCamera object.it will return the right info. Like this :`

QCamera *cam = new QCamera;
qDebug()<<QCameraInfo::availableCameras().count();`

I have one camera,so it returns 1 at last;

回答2:

Try to copy the mediaservice plugin folder into your application dir (where the exe resides).

At least that solved this specific problem for me.

回答3:

You need to resolve your dependencies (like Thomas D. mentioned). (take a look at http://doc.qt.io/qt-5/windows-deployment.html )

From yourpathof\Qt\...subdir...\bin

execute

windeployqt.exe --debug YOURPATH\Debug

or

windeployqt.exe YOURPATH\Debug

来源：https://stackoverflow.com/questions/42567750/i-have-two-webcams-but-qcamerainfoavailablecameras-returns-empty-array