cannot declare a managed variable in unmanaged classs

[codegurugeek]

guys,

how do you you all settle the above problem with a breeze..

i thought that __nogc class will give way to mix the unmanaged and managed types and declaration?

[cilu]

i thought that __nogc class will give way to mix the unmanaged and managed types and declaration?

The keyword __nogc on a class or struct indicates that it is an unmanaged C++ class or struct.

cannot declare a managed variable in unmanaged classs

To use manages types in unmanaged code you need to use the GCHandle struct.

[darwen]

To declare a managed variable reference in an unmanaged class you have to use the gcroot<> templated class e.g.

class CMyUnmanagedClass
{
public:
    CMyUnmanagedClass(System::String *psString)
    {
        m_psString = psString;
    }

    void Test()
    {
        System::Diagnostics::Debug::WriteLine(m_psString);
    }

private:
    gcroot<String *> m_psString;
} ;

It behaves like a smart pointer i.e. it has overloads for ->, = etc etc (as shown in the Test() method above).

Okay ?

You can also use gcroot in STL declarations : this is how you can have a std::vector of String * (for instance) e.g.

std::vector<gcroot<String *> > asStrings;

Darwen.