CLI/C++中混合类的使用

CLI/C++中混合类的使用

一 混合类

所谓混合类是指CLI/C++中native的Class中可以包含CLR对象，CLR的class也可以包含Naitve的对象。

1）native的class中包含CLR对象，必须通过gcroot<>或auto_gcroot<>。
2）CLR中的class中包含native的对象，必须是指针，也可以使用高手写的CAutoNativePtr智能指针。

注意：C#中不能调用CLI/C++中的Native的class。同样Native C++中也不能调用CLI/C++中的Ref的class。

二 实例

 高手的CAutoNativePtr类：

/***
    CAutoNativePtr - A smart pointer for using native objects in managed code.

    Author    :    Nishant Sivakumar
    Email    :    voidnish@gmail.com    
    Blog    :    http://blog.voidnish.com
    Web        :    http://www.voidnish.com     

    You may freely use this class as long as you include
    this copyright. 
    
    You may freely modify and use this class as long
    as you include this copyright in your modified version. 

    This code is provided "as is" without express or implied warranty. 
    
    Copyright ?Nishant Sivakumar, 2006.
    All Rights Reserved.
***/

#pragma once

template<typename T>  ref  class CAutoNativePtr
{
private:
    T* _ptr;

public:
    CAutoNativePtr() : _ptr(nullptr)
    {
    }

    CAutoNativePtr(T* t) : _ptr(t)
    {
    }

    CAutoNativePtr(CAutoNativePtr<T>% an) : _ptr(an.Detach())
    {
    }

    template<typename TDERIVED> 
        CAutoNativePtr(CAutoNativePtr<TDERIVED>% an) : _ptr(an.Detach())
    {
    }

    !CAutoNativePtr()
    {    
        delete _ptr;
    }

    ~CAutoNativePtr()
    {
        this->!CAutoNativePtr();
    }

    CAutoNativePtr<T>% operator=(T* t)
    {
        Attach(t);
        return *this;
    }

    CAutoNativePtr<T>% operator=(CAutoNativePtr<T>% an)
    {
        if(this != %an)
            Attach(an.Detach());
        return *this;
    }

    template<typename TDERIVED> 
        CAutoNativePtr<T>% operator=(CAutoNativePtr<TDERIVED>% an)
    {
        Attach(an.Detach());
        return *this;
    }

    static T* operator->(CAutoNativePtr<T>% an)
    {
        return an._ptr;
    }

    static operator T*(CAutoNativePtr<T>% an)
    {
        return an._ptr;
    }

    T* Detach()
    {
        T* t = _ptr;
        _ptr = nullptr;
        return t;
    }

    void Attach(T* t)
    {
        if(t)
        {    
            if(_ptr != t)
            {
                delete _ptr;
                _ptr = t;
            }
        }
        else
        {
#ifdef _DEBUG
            throw gcnew Exception(
                "Attempting to Attach() a nullptr!");
#endif
        }        
    }

    void Destroy()
    {
        delete _ptr;
        _ptr = nullptr;
    }
};

测试实例之CLI/C++文件：

//  MixedNativeAndCLIDLL.h

#pragma once
#include < string>
#include <iostream>
#include <gcroot.h>
#include <msclr/auto_gcroot.h>

#include "AutoNative.h"

using  namespace System;

namespace MixedNativeAndCLIDLL  {

    public class NativeClass
    {
    public:
        int *pX;    
        NativeClass(){pX = new int(10);}
        ~NativeClass()
        {
            if(pX != NULL)
            {
                delete pX;
                pX = NULL;
            }
        }        
    };

    public ref class RefClass
    {
    public:
        int x;    
        RefClass(){x = 20;}
    };

    public class MixedClass0
    {
        public:
            NativeClass nativeClass;
            //RefClass refClass; // error c3265 and error c3149
            gcroot<RefClass^> refClass1;

            std::string nativeStr;
            //System::String refStr; // error c3265 and error c3149
            gcroot<System::String^> refStr1;

            MixedClass0()
            {
                refClass1 = gcnew RefClass();
                refStr1 = gcnew System::String("i am a native class mixed some clr members.\n");
            }
            ~MixedClass0()
            {            
                delete refClass1;
                delete refStr1;
            }

            void PrintSelf()
            {
                System::Console::WriteLine("my name is MixedClass0");
                System::Console::WriteLine(refClass1->x);
                System::Console::WriteLine(refStr1);
            }
    };

    public class MixedClass1
    {
        public:
            NativeClass nativeClass;
            //RefClass refClass; // error c3265 and error c3149
            msclr::auto_gcroot<RefClass^> refClass1;

            std::string nativeStr;
            //System::String refStr; // error c3265 and error c3149
            msclr::auto_gcroot<System::String^> refStr1;

            MixedClass1()
            {
                refClass1 = gcnew RefClass();
                refStr1 = gcnew System::String("i am a native class with some clr members.\n");
            }
            ~MixedClass1()
            {
                // no need to delete.
            }        

            void PrintSelf()
            {
                System::Console::WriteLine("my name is MixedClass1");
                System::Console::WriteLine(refClass1->x);
                System::Console::WriteLine(refStr1);
            }
    };

    public ref class MixedClass2
    {
        public:
            //NativeClass nativeClass; // error c4368
            NativeClass * nativeClass1;
            RefClass^ refClass; 
            
            //std::string nativeStr; // error c4368
            std::string *nativeStr1;
            System::String^ refStr; //     

            MixedClass2()
            {
                nativeClass1 = new NativeClass();
                nativeStr1 = new std::string("i am a clr class with some native members.\n");
            }
            ~MixedClass2()
            {
                delete nativeClass1;
                delete nativeStr1;
            }
            !MixedClass2(){}

            void PrintSelf()
            {
                System::Console::WriteLine("my name is MixedClass2");
                std::cout<<*(nativeClass1->pX)<<std::endl;
                std::cout<<*nativeStr1<<std::endl;                
            }
    };
    
    public ref class MixedClass3
    {
        public:
            //NativeClass nativeClass; // error c4368
            CAutoNativePtr<NativeClass> nativeClass1;
            RefClass^ refClass; 
            
            //std::string nativeStr; // error c4368
            CAutoNativePtr<std::string> nativeStr1;
            System::String^ refStr; //     

            MixedClass3()
            {
                nativeClass1 = new NativeClass();
                nativeStr1 = new std::string("i am a clr class with some native members.\n");
            }
            ~MixedClass3(){}
            !MixedClass3(){}

            void PrintSelf()
            {
                System::Console::WriteLine("my name is MixedClass3");
                std::cout<<*(nativeClass1->pX)<<std::endl;
                std::cout<<*nativeStr1<<std::endl;                
            }
    };
}

测试实例之C#调用文件：

using System;
using System.Collections.Generic;
using System.Text;

namespace CsharpTest
{
    class Program
    {
        static void Main(string[] args)
        {
            MixedNativeAndCLIDLL.MixedClass0 mixedClass0 = new MixedNativeAndCLIDLL.MixedClass0();
            //mixedClass0.PrintSelf();
            MixedNativeAndCLIDLL.MixedClass1 mixedClass1 = new MixedNativeAndCLIDLL.MixedClass1();
            //mixedClass1.PrintSelf();
            MixedNativeAndCLIDLL.MixedClass2 mixedClass2 = new MixedNativeAndCLIDLL.MixedClass2();
            mixedClass2.PrintSelf();
            MixedNativeAndCLIDLL.MixedClass3 mixedClass3 = new MixedNativeAndCLIDLL.MixedClass3();
            mixedClass3.PrintSelf();
        }
    }
}

三 代码下载

http://www.cppblog.com/Files/mzty/MixedNativeAndCLITest.rar