SWIG, pass C++ array of classes back to C# example

Step 1 Create a C++ Windows DLL Project StudentDll

Step 2 Add Student.h file

#pragma once
#include
#include
class Student
{
public:
std::string FirstName;
std::string LastName;
Student(std::string _FirstName, std::string _LastName);
Student();
};

std::vector GetStudents();

Step 3 Add Student.cpp file

#include "stdafx.h"

#include "Student.h"

Student::Student(std::string _FirstName, std::string _LastName)

{

FirstName = _FirstName;

LastName = _LastName;

}

Student::Student()

{

}

std::vector GetStudents()

{

std::vector sv;

sv.push_back(Student("John", "Smith"));

sv.push_back(Student("Mary", "Boyle"));

return sv;

}

Step 4 Add Student.i file

%module StudentDll
%include "std_string.i"

%apply const std::string& {std::string* FirstName};
%apply const std::string& {std::string* LastName};
%{
#include "student.h"
%}

%include

%include "student.h"

Step 4a

Select Student.i, Properties, General, Item Type as Custom Build Tool.

Select Apply to create the Custom Build Tool property group.

In Custom Build Tool, General, Command Line enter:
swig -csharp -c++ -outdir  Student.i

In Outputs, enter Student_wrap.cxx, and click OK to close the dialog.

Right-click Student.i and Compile. This should create four files: three in the C# Generated folder and one in the C++ project.

Create a Generated Files filter in the C++ project and add Student_wrap.cxx to it.

Step 5 Add StudentVector.i file

%module StudentVectorDll

%include std_vector.i
%include std_string.i

/* allow partial c# classes */
%typemap(csclassmodifiers) SWIGTYPE "public partial class"

/* generate template around vector */

%template(StudentVector) std::vector;


Step 5a

Select Student.i, Properties, General, Item Type as Custom Build Tool.

Select Apply to create the Custom Build Tool property group.

In Custom Build Tool, General, Command Line enter:
swig -csharp -c++ -outdir GeneratedFolderPath StudentVector.i

In Outputs, enter StudentVector_wrap.cxx, and click OK to close the dialog.

Right-click StudentVector.i and Compile. This should create four files: three in the C# Generated folder and one in the C++ project.

Create a Generated Files filter in the C++ project and add StudentVector_wrap.cxx to it.

Step 6 Create a C# .Net Framework project StudentConsumer

Fill in the default Program.cs file as follow

using System.Text;
using System.Threading.Tasks;

namespace StudentConsumer
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Hello World");
            var s = StudentDllPINVOKE.GetStudents();
            StudentVector sv = new StudentVector(s, true);
            var sv0 = sv[0];
            var sv00 = SWIGTYPE_p_Student.getCPtr(sv0);
            var sv01 = new Student(sv00);
            Console.WriteLine(sv01.FirstName + ", " + sv01.LastName);

            Console.ReadKey();
        }
    }

}

Step 7 Add Generated folder in the C# Student Consumer project

Step 7a Add the content of GeneratedFolderPath folder from C++ StudentDll project to the Generated folder

Step 7b Add an extra Constructor in the Student.cs

public class Student : global::System.IDisposable {
  private global::System.Runtime.InteropServices.HandleRef swigCPtr;
  protected bool swigCMemOwn;

  public Student(global::System.Runtime.InteropServices.HandleRef _swigCPtr)
    {
        swigCPtr = _swigCPtr;
    }

Step 8 Set the StartUp project as StudentConsumer and Run it

swig is a good tool for converting interpolating code between C++ and other languages
http://www.swig.org/