C++/CLI Cheat Sheet

My C++/CLI pocket reference...

• Declare a string

System::String^ myString = "";

• Declare a null reference

System::String^ myString = nullptr;

• Pass a string by reference to a method (the reference to the string will be modified, not the string itself since strings are immutable). Use %:

void MyMethod(System::String^% myString)

{

}

• Declare an array of strings

    cli::array<System::String^>^ stringArray = gcnew cli::array<System::String^>{"Skype","Blogger"};

• Declare a managed member inside a native class

class IAmNative

{

    gcroot<IAmManaged^ > managedMember;

public:

    IAmNative():managedMember(gcnew IAmManaged())

    {

    }

};

• Declare a managed member that will self destroy

#include <msclr\auto_gcroot.h> 

class IAmStillNative

{

    msclr::auto_gcroot<IAmStillManaged^> managedMember; // Will be disposed when IAmStillNative is destroyed

public:

    IAmStillNative():managedMember(gcnew IAmStillManaged())

    {

    }

};

• Convert a native STL string to a managed string

System::String^ ToManaged(const std::string& nativeString)

{

    return gcnew System::String(nativeString.c_str());

}

• The same backwards:

std::string ToNative(System::String^ managedString)

{

   char* str = (char*)(void*)System::Runtime::InteropServices::Marshal::StringToHGlobalAnsi(managedString).ToPointer();

   std::string result(str);

   System::Runtime::InteropServices::Marshal::FreeHGlobal((System::IntPtr)str);

   return result;

}

Things you can do

• Instantiate managed types, call managed methods from native code provided it compiles with /CLR.
• Instantiate native types, call native methods from managed code
• Link to the native types of a mixed static lib (/clr)
• Declare managed methods that have native types in their signature

Things you can't do

• Link to the managed types of a mixed static lib
• Link to managed types in a DLL if those managed types have methods with native types in their signature.