基于halcon的qt使用定时器调用笔记本自带摄像头

最近想用qt做一个摄像头的界面，于是通过halcon调用摄像头，在导出到c++代码。
以下是导出的cpp文件的action函数

// Local iconic variables
  HObject  ho_Image;

  // Local control variables
  HTuple  hv_AcqHandle;

  //Image Acquisition 01: Code generated by Image Acquisition 01
  OpenFramegrabber("DirectShow", 1, 1, 0, 0, 0, 0, "default", 8, "rgb", -1, "false", 
      "default", "[0] USB Camera", 0, -1, &hv_AcqHandle);
  GrabImageStart(hv_AcqHandle, -1);
  while (0 != 1)
  {
    GrabImageAsync(&ho_Image, hv_AcqHandle, -1);
    //Image Acquisition 01: Do something
  }
  CloseFramegrabber(hv_AcqHandle);

将此代码复制进qt程序中，我们需要先配置qt的halcon环境，参考我的上一篇博客：
链接: https://blog.csdn.net/Philloasd/article/details/106366474

在Qt creator中新建一个label以及两个putton控件

mainwindow.h代码如下

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include 
#include"Halcon.h"
#include"cpp/HalconCpp.h"
#include"halconcpp\HalconCpp.h"
using namespace HalconCpp;

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

    // Local iconic variables
    HObject  ho_Image;

    // Local control variables
    HTuple  hv_AcqHandle,hv_WindowHandle;

    Hlong windID;

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

private slots:
    void on_pushButton_start_clicked();

    void on_pushButton_stop_clicked();

private:
    Ui::MainWindow *ui;
};

#endif // MAINWINDOW_H

mainwindows.cpp代码如下

#include "mainwindow.h"
#include "ui_mainwindow.h"

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

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

void MainWindow::on_pushButton_start_clicked()
{
    OpenFramegrabber("DirectShow", 1, 1, 0, 0, 0, 0, "default", 8, "rgb", -1, "false","default", "[0] USB Camera", 0, -1, &hv_AcqHandle);
    windID = (Hlong)this->ui->label_camera->winId();
    GrabImageStart(hv_AcqHandle, -1);

    //    在openwindow前先抓取一帧图片
    GrabImage(&ho_Image,hv_AcqHandle);
    OpenWindow(0,0,ui->label_camera->width(),ui->label_camera->height(),windID,"visible","",&hv_WindowHandle);
    HDevWindowStack::Push(hv_WindowHandle);

    while(0!=1)
    {
        GrabImage(&ho_Image, hv_AcqHandle);
        if(HDevWindowStack::IsOpen())
        {
            DispObj(ho_Image,HDevWindowStack::GetActive());
            WaitSeconds(0.1);//参数影响帧率
        }
    }
    QCoreApplication::processEvents(QEventLoop::AllEvents,100);//防止卡死
}

void MainWindow::on_pushButton_stop_clicked()
{
    CloseFramegrabber(hv_AcqHandle);//关闭摄像头
}

此时点击开始按钮我们是可以成功的在我们设定的label控件上实时显示摄像的内容，但是我们退出的时候会报错。

图片显示我们的内存发生了泄露，通过在vs中编译发现是退出时没有跳出while的死循环，于是参考这篇文章改用定时器代替while循环。
链接: https://blog.csdn.net/hexuyangguang/article/details/106219104.
修改后的mainwindow.h代码如下：

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include 
#include
#include"Halcon.h"
#include"cpp/HalconCpp.h"
#include"halconcpp\HalconCpp.h"
using namespace HalconCpp;

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

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

    // Local iconic variables
    HalconCpp::HObject  ho_Image;

    // Local control variables
    HalconCpp::HTuple  hv_AcqHandle,hv_WindowHandle;

    Hlong windID;

private slots:
    void on_pushButton_start_clicked();

    void on_pushButton_stop_clicked();

    void camera();//放置需要定时器循环的代码

private:
    Ui::MainWindow *ui;
    QTimer * timer;
};

#endif // MAINWINDOW_H

mainwindow.cpp代码如下：

#include "mainwindow.h"
#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    timer = new QTimer(this);

    connect(timer,SIGNAL(timeout()),this,SLOT(camera()));
    connect(ui->pushButton_stop,SIGNAL(clicked(bool)),qApp,SLOT(quit()));
}

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

void MainWindow::on_pushButton_start_clicked()
{
    timer->start(20);//定时器开始工作,参数影响帧率
    //Image Acquisition 01: Code generated by Image Acquisition 01
    OpenFramegrabber("DirectShow", 1, 1, 0, 0, 0, 0, "default", 8, "rgb", -1, "false","default", "[0] USB Camera", 0, -1, &hv_AcqHandle);
    windID = (Hlong)this->ui->label_camera->winId();
    GrabImageStart(hv_AcqHandle, -1);

    //    在openwindow前先抓取一帧图片
    GrabImage(&ho_Image,hv_AcqHandle);
    OpenWindow(0,0,ui->label_camera->width(),ui->label_camera->height(),windID,"visible","",&hv_WindowHandle);
    HDevWindowStack::Push(hv_WindowHandle);
}

void MainWindow::on_pushButton_stop_clicked()
{
    timer->stop();
    CloseFramegrabber(hv_AcqHandle);
}

void MainWindow::camera()
{
    GrabImage(&ho_Image, hv_AcqHandle);
    if(HDevWindowStack::IsOpen())
    {
        DispObj(ho_Image,HDevWindowStack::GetActive());
    }
}

此时再次运行就没问题了！！！