camera=new QCamera(this);
camera->setCaptureMode(QCamera::CaptureVideo);
viewfriend=new QCameraViewfinder(this);
viewfriend->setMinimumSize(200,200);
viewfriend->move(0,0);
camera->start();
videoProbe=new QVideoProbe;
if(!videoProbe->setSource(camera))ui->statusBar->showMessage("videoProbe not open");
connect(videoProbe,SIGNAL(videoFrameProbed(QVideoFrame)),this,SLOT(showe(QVideoFrame)));
camera->setViewfinder(viewfriend);
请问setSource(camera);返回false ,怎么回事啊?