在C++/CLI中通過包裝器（派生託管類）調用派生本機類的重寫方法

Question

我有6個類的故事：3個託管和3個本機。

3個託管類是ManagedChildA，ManagedChildB和ManagedParent。

ManagedChildA，ManagedChildB都從ManagedParentA繼承。

3個本地類是NativeChildA，NativeChildB和NativeParent。

NativeChildA，NativeChildB都從NativeParentA繼承。

此外，ManagedChildA包裝NativeChildB，ManagedChildB包裝ManagedChildB和ManagedParentA包裝NativeParentA。

現在，這裏的故事gows歪：

ManagedParentA有包裝NativeParentA的NativeExecute）稱爲ManagedExecute的方法（（）。當這個方法被調用時，一切都運行平穩。 （）包裝NativeChildA :: NativeExecute（）和ManagedChildB :: ManagedExecute（）包裝NativeChildB :: NativeExecute（），NativeChildB，ManagedChildB重寫ManagedExecute（）以提供它們自己的實現。

例如，當調用ManagedChildA的重寫ManagedExecute（）時，NativeChildA :: NativeExecute（）會被調用，儘管存在System.AccessViolation錯誤。也就是說，找不到NativeChildA的原始父指針。

我想指針已經從原來的地址移開。我在互聯網上閱讀時，必須指出防止垃圾收集器（GC）移動內存，但我不知道該如何固定，因爲異常會在本機級別拋出。任何有用的提示？

實施例：

//C++ -native classes 
class NativeFoo 
{ 
    public: 
    NativeFoo(): tested(true){} 
    virtual void execute() 
    { 
    std::cout << "Native Foo" << std::endl; 
    } 

    protected: 
    bool tested; 

}; 


class NativeBarA :NativeFoo 
{ 
    public: 
    NativeBarA(): NativeFoo(){} 
    void execute() 
    { 
    std::cout << "Native Bar A" << std::endl; 
    } 
}; 

class NativeBarB : public NativeFoo 
{ 
    public: 
    NativeBarB() :NativeFoo(){} 
    void execute() 
    { 
    std::cout << "Native Bar B" << std::endl; 
    } 
}; 

//CLI interface 
public interface class IExecutable 
{ 
    public: 
     Execute(); 
} 

//C++-CLI classes 
public ref class ManagedFoo: public IExecutable 
{ 

    private: 
    NativeFoo* impl; 

    public: 

ManagedFoo(): impl(NULL) 
{ 
    impl = new NativeFoo(); 
} 

void __clrcall Execute() 
{ 
    impl->execute(); 
} 
}; 

public ref class ManagedBarA: public ManagedFoo 
{ 

    private: 
    NativeBarA* impl; 

    public: 

ManagedBarA(): ManagedFoo(), impl(NULL) 
{ 
    impl = new NativeBarA(); 
} 

void __clrcall Execute() override 
{ 
    impl->execute(); 
} 
}; 

public ref class ManagedBarB: public ManagedFoo 
{ 

    private: 
    NativeBarB* impl; 

    public: 

ManagedBarB(): ManagedFoo(), impl(NULL) 
{ 
    impl = new NativeBarB(); 
} 

void __clrcall Execute() override 
{ 
    impl->execute(); 
} 
}; 


//Calling code 
[STAThread] 
static void Main() 
{ 
    ManagedFoo^ mfoo = gcnew ManagedFoo(); 
    ManagedBarA mbarA = gcnew ManagedBarA(); 
    ManagedBarB mbarB = gcnew ManagedBarB(); 
    mfoo->Execute(); //OK 
    mbarA->Execute(); //Error. Debugger sees value of tested as false 
    mBarB->Execute(); //Error 
} 

Answer 1

該片段是非常低的質量，它充滿了不可編譯的代碼。一旦我修正了所有的錯誤，我無法重現。

#include "stdafx.h" 
#include <iostream> 
using namespace System; 

//C++ -native classes 
class NativeFoo 
{ 
public: 
    NativeFoo(): tested(true){} 
    virtual void execute() 
    { 
     std::cout << "Native Foo" << std::endl; 
    } 

protected: 
    bool tested; 

}; 


class NativeBarA :NativeFoo 
{ 
public: 
    NativeBarA(): NativeFoo(){} 
    void execute() 
    { 
     std::cout << "Native Bar A" << std::endl; 
    } 
}; 

class NativeBarB : public NativeFoo 
{ 
public: 
    NativeBarB() :NativeFoo(){} 
    void execute() 
    { 
     std::cout << "Native Bar B" << std::endl; 
    } 
}; 

//CLI interface 
public interface class IExecutable 
{ 
public: 
    void Execute(); 
}; 

//C++-CLI classes 
public ref class ManagedFoo: public IExecutable 
{ 

private: 
    NativeFoo* impl; 

public: 

    ManagedFoo(): impl(NULL) 
    { 
     impl = new NativeFoo(); 
    } 

    virtual void Execute() 
    { 
     impl->execute(); 
    } 
}; 

public ref class ManagedBarA: public ManagedFoo 
{ 

private: 
    NativeBarA* impl; 

public: 

    ManagedBarA(): ManagedFoo(), impl(NULL) 
    { 
     impl = new NativeBarA(); 
    } 

    virtual void __clrcall Execute() override 
    { 
     impl->execute(); 
    } 
}; 

public ref class ManagedBarB: public ManagedFoo 
{ 

private: 
    NativeBarB* impl; 

public: 

    ManagedBarB(): ManagedFoo(), impl(NULL) 
    { 
     impl = new NativeBarB(); 
    } 

    virtual void __clrcall Execute() override 
    { 
     impl->execute(); 
    } 
}; 


//Calling code 
[STAThread] 
int main(array<System::String ^> ^args) 
{ 
    ManagedFoo^ mfoo = gcnew ManagedFoo(); 
    ManagedBarA^ mbarA = gcnew ManagedBarA(); 
    ManagedBarB^ mbarB = gcnew ManagedBarB(); 
    mfoo->Execute(); //OK 
    mbarA->Execute(); //Fine 
    mbarB->Execute(); //Fine 
}