托管C++——在C#中使用C++

下面就用一个完整的实例来详细说明怎样用托管C++封装一个C++类以提供给C#使用。

现有一个Detector类需要使用，首先，要创建一个托管C++的DLL工程DAADll，然后在里面添加下面的代码：

DAADll.h

#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/core/core.hpp>
#include <opencv2/contrib/contrib.hpp>
#include <opencv2/objdetect/objdetect.hpp>
#include "../libmi_dpm/face_detector.hpp"

#pragma comment(lib, "../lib/lib3000fps.lib")
#pragma comment(lib, "../lib/liblinear.lib")
#pragma comment(lib, "../lib/libmi_dpm.lib")
//#pragma comment(lib, "MSCOREE.lib")

using namespace System;
using namespace System::Collections::Generic;
using namespace System::Text;
using namespace System::Drawing;

namespace DAADLL{
    public ref class daaDll
    {
    public:
        daaDll();
        ~daaDll();
        !daaDll();
        Int32 detectFasterMerge(cv::Mat& img);
        Int32 detectFasterMerge(Image^ img);
        void clean();
    private:
        mi_dpm::Detector * face_det;
    };
}

这样就可以引用Detector类；

在DAADll.cpp中加入需要调用的功能

#include "daaDll.h"

#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/core/core.hpp>
#include <opencv2/contrib/contrib.hpp>
#include <opencv2/objdetect/objdetect.hpp>
#include "BitmapConverter.h"
#include "ImageHelper.h"

using namespace System::IO;

using namespace DAADLL;
using namespace DAADLL::Util;

daaDll::daaDll()
{
    face_det = new mi_dpm::Detector();
    face_det->detectInit();
}

daaDll::~daaDll()
{
    this->!daaDll();
}

daaDll::!daaDll()
{
    face_det->detectClear();
    if (face_det != NULL)
    {
        free(face_det);
        face_det = NULL;
    }
}

void daaDll::clean()
{
    face_det->detectClear();
}

Int32 daaDll::detectFasterMerge(cv::Mat& cvImg)
{
    std::vector<cv::Rect> rects;
    std::vector<float> scores;
    std::vector<int> picked;
    if (cvImg.channels() >= 3)
    {
        cv::cvtColor(cvImg, cvImg, CV_BGR2GRAY);
        cv::waitKey(1000);
    }
    picked = face_det->detectFasterMerge(cvImg, rects, scores);
    int n = picked.size();
    for (int i = 0; i < n; i++)
    {
        int idx = picked[i];
        cv::rectangle(cvImg, rects[idx], cv::Scalar(0, 125, 255), 2);
    }
    cv::imwrite("tmp_timg_FastMerge.jpg", cvImg);
    cv::waitKey(10);
    return n;
}

Int32 daaDll::detectFasterMerge(Image^ img)
{
    cv::Mat cvImg = BitmapConverter::ToMat(img);
    return detectFasterMerge(cvImg);
}

最后在C#项目（我这边是主界面winform）中引用创建的DAADll项目即可。