Question

在编写代码时，我观察到如果我在托管类之前声明非托管类，代码编译时没有错误：

#include <opencv2\core\core.hpp>
#include <opencv2\imgproc\imgproc.hpp>
#include <opencv2\highgui\highgui.hpp>

using namespace System;

namespace OpenCVDll
{
    public class OpenCV
    {
    public:
        //members
        cv::Mat CalibrationDark;
        cv::Mat CalibrationBright;
        unsigned short* dark;
        unsigned short* bright;

        //methods
        void DarkCalibration();
        void BrightCalibration();
        OpenCV(){}
        ~OpenCV();
    };

    public ref class MOpenCV
    {
    public:
        //members
        OpenCV* UOpenCV; 

        //methods
        MOpenCV();
        !MOpenCV();
        ~MOpenCV();

    private:
        //methods
        void Destruction();
    };
}`

但是，如果我以其他方式声明类，首先是托管，然后是非托管：

#include <opencv2\core\core.hpp>
#include <opencv2\imgproc\imgproc.hpp>
#include <opencv2\highgui\highgui.hpp>

using namespace System;

namespace OpenCVDll
{
    public ref class MOpenCV
    {
    public:
        //members
        OpenCV* UOpenCV; 

        //methods
        MOpenCV();
        !MOpenCV();
        ~MOpenCV();

    private:
        //methods
        void Destruction();
    };

    public class OpenCV
    {
    public:
        //members
        cv::Mat CalibrationDark;
        cv::Mat CalibrationBright;
        unsigned short* dark;
        unsigned short* bright;

        //methods
        void DarkCalibration();
        void BrightCalibration();
        OpenCV(){}
        ~OpenCV();
    };
}

我丢失了类型错误：错误C4430：缺少类型说明符 - 假定为int。注意：C ++不支持default-int

为什么会这样？

Answer 1

问题是当编译器到达行OpenCV* UOpenCV;时，尚未声明类OpenCV。

您可以在OpenCV课程之前使用MOpenCV课程的前向声明解决此问题。

public class OpenCV;

public ref class MOpenCV
{
public:
    //members
    OpenCV* UOpenCV; 

    ...
};

public class OpenCV
{
    ...
};

C ++ / cli：非托管类和托管类的声明

1 个答案: