Marshaling list string from C++ to C#

Question

Hi guys, now i studying the way to marshalling list string in struct from C++ to C#. The structure of struct same like:
In C++:
struct A
{
wchar_t Name[24][16];
}

in C#:
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
Class A
{
[MarshalAs(UnmanagedType.ByValArray, SizeConst =24 * 4)]
public string[] Name= new string[24];
}

What is the best way to solve this case ?

Answer 1

Try these definitions:

[StructLayout( LayoutKind.Sequential, CharSet = CharSet.Unicode )]
struct Name
{
    [MarshalAs( UnmanagedType.ByValTStr, SizeConst = 16 )]
    public string Value;
}

[StructLayout( LayoutKind.Sequential, CharSet = CharSet.Unicode )]
class A
{
    [MarshalAs( UnmanagedType.ByValArray, SizeConst = 24 )]
    public Name[] Name = new Name[24];
}

[DllImport( @"MyDll.dll", CallingConvention = CallingConvention.StdCall )]
extern static void Test1( [In, Out] A a );

. . .

A a = new A( );
a.Name[1].Value = "str1";

Test1( a );

 

// In C++:

struct A
{
    wchar_t Name[24][16];
};

extern "C" __declspec( dllexport ) void __stdcall Test1( A * a ) 
{
    wcscpy_s( a->Name[2], L"str2" );
}