【Qt】使用QCamera获取摄像头，并使用图像视图框架QGraphics*来显示

代码下载

https://download.csdn.net/download/u010168781/10373174

头文件

#ifndef CAMERATEST_H

#define CAMERATEST_H

#include 
#include 
#include 
#include 

namespace Ui {
class CameraTest;
}

class QCamera;
class QCameraImageCapture;
class QGraphicsVideoItem;
class QGraphicsScene;
class QGraphicsView;
class QGraphicsTextItem;

class CameraTest : public QMainWindow
{
    Q_OBJECT

public:
    explicit CameraTest(QWidget *parent = 0);
    ~CameraTest();

private:
    Ui::CameraTest *ui;

private slots:
    void slotExitBtn();
    void slotImageCaptureBtn(int, QImage image);
    void slotTimer();

private:
    QCamera*             myCamera;
    QCameraImageCapture* myImageCapture;

    QGraphicsVideoItem* myGraphicsVideoItem;
    QGraphicsScene* myGraphicsScene;
    QGraphicsView*  myGraphicsView;

    QGraphicsTextItem* myGraphicsTextItem;

    QTimer* myTimer;
    bool showText;
};

#endif // CAMERATEST_H

主程序

#include "CameraTest.h"
#include "ui_CameraTest.h"

#include 
#include 
#include 
#include 
#include 

#include 
#include 
#include 
#include 
#include 
#include 
#include 

CameraTest::CameraTest(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::CameraTest)
{
    ui->setupUi(this);

    setWindowTitle("QCamera");
    resize(800, 600);

    myGraphicsVideoItem = new QGraphicsVideoItem(this);
    myGraphicsVideoItem->setSize(QSizeF(640,480));
    myGraphicsVideoItem->setPos(0,0);

    myGraphicsTextItem = new QGraphicsTextItem(this);
    myGraphicsTextItem->setDefaultTextColor(QColor("red"));
    myGraphicsTextItem->setPlainText("hello world");

    myGraphicsScene = new QGraphicsScene(this);
    myGraphicsScene->addItem(myGraphicsVideoItem);
    myGraphicsScene->addItem(myGraphicsTextItem);

    myGraphicsView = new QGraphicsView(this);
    myGraphicsView->setScene(myGraphicsScene);

    myCamera = new QCamera(this);
    myImageCapture = new QCameraImageCapture(myCamera);
    myImageCapture->setCaptureDestination(QCameraImageCapture::CaptureToFile);
    myCamera->setCaptureMode(QCamera::CaptureStillImage);
    myCamera->setViewfinder(myGraphicsVideoItem);

    QPushButton* capBtn = new QPushButton("截图",this);
    QPushButton* exitBtn = new QPushButton("退出",this);
    connect(capBtn, SIGNAL(clicked()), myImageCapture, SLOT(capture()));
    connect(exitBtn, SIGNAL(clicked()), this, SLOT(slotExitBtn()));
    connect(myImageCapture, SIGNAL(imageCaptured(int,QImage)), this, SLOT(slotImageCaptureBtn(int,QImage)));

    QVBoxLayout *mainLayout = new QVBoxLayout(ui->centralWidget);
    mainLayout->addWidget(myGraphicsView);
    mainLayout->addWidget(capBtn);
    mainLayout->addWidget(exitBtn);

    //在此处start，没有反应，不显示摄像头内容
    //m_pCamera->start();

    myTimer = new QTimer(this);
    //触发时间100ms，需要根据自己的情况调整，我的测试是在少于50ms触发，不显示摄像头
    myTimer->singleShot(100,this,SLOT(slotTimer()));
}

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

void CameraTest::slotExitBtn()
{
    myCamera->stop();
    close();
}

void CameraTest::slotImageCaptureBtn(int, QImage image)
{
    QString savepath = QFileDialog::getSaveFileName(this,"Save Capture","Capture","Image png(*.png);;Image jpg(*.jpg);;Image bmp(*.bmp)");
    if(!savepath.isEmpty()){
        image.save(savepath);
    }
}

void CameraTest::slotTimer()
{
    myCamera->start();
}