C++/CLI 内 delete 释放内存的有关问题

using namespace System;public ref struct APP{    String^ TheString;    APP(String^ inString)    {        TheString = inString;    }};public ref class BPP{public: property APP^ TheAPP;public:    BPP(APP^ inAPP)    {        TheAPP = inAPP;    }};public ref class CPP{public: property APP^ TheAPP;public:    CPP(APP^ inAPP)    {        TheAPP = inAPP;    }};int main(){    APP^ app = gcnew APP("Weird.");    CPP^ cpp = gcnew CPP(app);    delete cpp;    Console::WriteLine(cpp->TheAPP->TheString);    Console::Read();    return 0;}