QT - connect USB camera

function ： Use QT Connect USB camera , Click the button to display the screen

QT += multimedia
QT += multimediawidgets

#include "camera.h"
#include "ui_camera.h"

Camera::Camera(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Camera)
{
    
    ui->setupUi(this);
    iniCamera();
}

Camera::~Camera()
{
    
    delete ui;
}

void Camera::iniCamera()
{
    

    cameras = QCameraInfo::availableCameras();// Get a list of cameras 
    qDebug()<<cameras.size();

    for(int i = 0;i<cameras.size();i++)
        ui->comboCamera->addItem(cameras[i].description());// Camera description 

}

void Camera::on_camStartBtn_clicked()
{
    
    curCamera=new QCamera(cameras[ui->comboCamera->currentIndex()],this);// newly build QCamera
    curCamera->setViewfinder(ui->widget); // Set viewfinder preview 
    curCamera->start();
}

#ifndef CAMERA_H
#define CAMERA_H

#include <QWidget>
#include <QCameraInfo>
#include <QCamera>
#include <QLabel>

#include <QCameraViewfinder>
#include <QCameraImageCapture>
#include <QMediaRecorder>

namespace Ui {
    
class Camera;
}

class Camera : public QWidget
{
    
    Q_OBJECT

public:
    explicit Camera(QWidget *parent = nullptr);
    ~Camera();
    void iniCamera();// Camera initialization 

    QCamera *curCamera=Q_NULLPTR;//
    QList<QCameraInfo> cameras;// List of available cameras 

    QCameraImageCapture *imageCapture; // Screenshots 
    QMediaRecorder* mediaRecorder;// videotape 

private slots:
    void on_camStartBtn_clicked();

private:
    Ui::Camera *ui;
};

#endif // CAMERA_H

Realization effect