// Form1.h
#include "control.h"
public __gc class Form1 : public System::Windows::Forms::Form
{
...
  controle *myControl;
}

// Controle.h
#include "Form1.h"
__gc public class Controle :  public System::ComponentModel::Component
{
...
   Form1 *myForm;
}

Controle(Form1 *inForm)
{
   myForm = inForm;
}

myControl = new Controle(this);

// a.h
class B;
class A
{
   B* pB;
   ...
};

// a.cpp
#include "a.h"
#include "b.h"

// b.h
class A;
class B
{
   A* pA;
   ...
};

// b.cpp
#include "a.h"
#include "b.h"

#pragma once




namespace test
{
   using namespace System;
   using namespace System::ComponentModel;
   using namespace System::Collections;
   using namespace System::Windows::Forms;
   using namespace System::Data;
   using namespace System::Drawing;


public __gc class controle;
   /// <summary>
   /// Summary for Form1
   ///
   /// WARNING: If you change the name of this class, you will need to change the
   ///          'Resource File Name' property for the managed resource compiler tool
   ///          associated with all .resx files this class depends on.  Otherwise,
   ///          the designers will not be able to interact properly with localized
   ///          resources associated with this form.
   /// </summary>
public __gc class Form1 : public System::Windows::Forms::Form
{   
public:
   Form1(void)
   {
      InitializeComponent();
      //unControle = new controle();

   }

protected:
   void Dispose(Boolean disposing)
   {
      if (disposing && components)
      {
         components->Dispose();
      }
      __super::Dispose(disposing);
   }

private:
   /// <summary>
   /// Required designer variable.
   /// </summary>
   System::ComponentModel::Container * components;
private: System::Windows::Forms::CheckBox *  checkBox1;
       controle *unControle;


       /// <summary>
       /// Required method for Designer support - do not modify
       /// the contents of this method with the code editor.
       /// </summary>
       void InitializeComponent(void)
       {
          this->checkBox1 = new System::Windows::Forms::CheckBox();
          this->SuspendLayout();
          //
          // checkBox1
          //
          this->checkBox1->Location = System::Drawing::Point(176, 176);
          this->checkBox1->Name = S"checkBox1";
          this->checkBox1->TabIndex = 0;
          this->checkBox1->Text = S"checkBox1";
          //
          // Form1
          //
          this->AutoScaleBaseSize = System::Drawing::Size(5, 13);
          this->ClientSize = System::Drawing::Size(292, 266);
          this->Controls->Add(this->checkBox1);
          this->Name = S"Form1";
          this->Text = S"Form1";
          this->Load += new System::EventHandler(this, Form1_Load);
          this->ResumeLayout(false);

       }   
private: System::Void Form1_Load(System::Object *  sender, System::EventArgs *  e)
       {

          unControle = new controle(this);
          //this->Controls->Add(unControle->textBox1);
          //unControle->textBox1->Text = "test";
       }

};
}

#pragma once

using namespace System;
using namespace System::ComponentModel;
using namespace System::Collections;
using namespace System::Diagnostics;



public __gc class Form1;
namespace test
{
   /// <summary>
   /// Summary for controle
   /// </summary>

public __gc class controle :  public System::ComponentModel::Component
{
public:
   controle(Form1 *inForm)
   {
      lForm = inForm;
      InitializeComponent();

   }
   controle(System::ComponentModel::IContainer *container) : components(0)
   {
      /// <summary>
      /// Required for Windows.Forms Class Composition Designer support
      /// </summary>

      container->Add(this);
      InitializeComponent();
   }

protected:
   void Dispose(Boolean disposing)
   {
      if (disposing && components)
      {
         components->Dispose();
      }
      __super::Dispose(disposing);
   }
public: System::Windows::Forms::TextBox *  textBox1;


private:
   /// <summary>
   /// Required designer variable.
   /// </summary>
   System::ComponentModel::Container *components;
   Form1 *lForm;

   /// <summary>
   /// Required method for Designer support - do not modify
   /// the contents of this method with the code editor.
   /// </summary>      
   void InitializeComponent(void)
   {
      this->textBox1 = new System::Windows::Forms::TextBox();
      //
      // textBox1
      //
      this->textBox1->Location = System::Drawing::Point(17, 17);
      this->textBox1->Name = S"textBox1";
      this->textBox1->TabIndex = 0;
      this->textBox1->Text = S"textBox1";

   }
};
}

...

void SetParent(Form1* f)
{
   this->pForm1 = f;
}

...
MonControl = new MonControl();
MonControl->SetParent(this);

using namespace test;