Hi I've create a C++ managed Class as :

*.h file
--------
#pragma once

#include "afxcmn.h"
using namespace System::Design;
using namespace System::Drawing::Design;
using namespace System::ComponentModel;
using namespace System::ComponentModel::Design;

namespace VXP_Editors
{
 ref class VXP_ColumnEditor : public
System::ComponentModel::Design::CollectionEditor
 {
  public:
   VXP_ColumnEditor(void);
 };
}

and *.cpp file
--------------
#include "stdafx.h"

#include "VXP_ColumnEditor.h"

namespace VXP_Editors
{
 #pragma region VXP_ColumnEditor
   
  VXP_ColumnEditor::VXP_ColumnEditor(void)
  {
  }
 #pragma endregion
}

when i compile it, VC++.NET displays errors :

l:\editors\VXP_ColumnEditor.h(5) : error C2039: 'Design' : is not a
member of 'System'
l:\editors\VXP_ColumnEditor.h(5) : error C2871: 'Design' : a namespace
with this name does not exist
l:\editors\VXP_ColumnEditor.h(13) : error C2039: 'CollectionEditor' : is
not a member of 'System::ComponentModel::Design'
l:\editors\VXP_ColumnEditor.h(13) : error C2504: 'CollectionEditor' :
base class undefined

how is it possible ?
in my project property options, i add the references to the right
SystemDesign.dll

thx for help.

Al.