Re: Forms and VC++

"William DePalo [MVP VC++]" <>
Fri, 17 Nov 2006 12:32:39 -0500
"blangela" <> wrote in message

I teach an introductory and intermediate C++ programming courses at a
local college ( ) . In the past if I wanted
to give my students a taste of creating "Windows App" in C++, I was
pretty well forced into giving them an introduction to MFC. I am told
(I have not yet had a chance to try it myself) that this "forms"
capability is easier to use than MFC. Is this true?

If so, would this CLR/C++ provide a way for me to teach C++ without
restricitng all my course assignments to console type apps?

Yes, it would.

It begs the question, though, as to whether your students would be confused.
I'm no teacher, but I would suggest that you not introduce MC++ or C++/CLI
in a first semester course in which you also teach ISO C++.

Whether the rest of this post will be useful or noise in an open question.

The code I have appended below is something I put together in response to a
question some time ago (btw p.o. are the initials of the guy who asked the
question). In any event, the sample below is a Win32 application which is
compiled by VS2003 using the /clr switch. If the application finds "console"
as its sole command line argument it allocates a console and prints "Hello,
world". If it finds "window" then it creates a window, draws a blue circle
within it, draws a red line across it and draws the text "Hello, world".

The good news is that there is a lot less code there than there would be if
I had written it to the SDK. The bad news is that it is a long way from ISO


#include "po2.h"

void HelloWorld::Main()
 Application::Run( new HelloWorld() );

void HelloWorld::Main2()
 int h;
 IntPtr handle;
 FileStream __gc *fs;
 StreamWriter __gc *sw;

 if ( AttachConsole(-1) == 0 )

 h = GetStdHandle(-11);
 fs = new FileStream(IntPtr(h), FileAccess::Write);
 sw = new StreamWriter(fs);
 sw->AutoFlush = true;

 Console::WriteLine("Hello, world!");

 Text = "Hello, world!";
 BackColor = Color::White;

void HelloWorld::OnPaint(PaintEventArgs *pea)
 Graphics __gc *grfx = pea->Graphics;
 Rectangle rc;

 grfx->DrawString("Hello, World!", Font, Brushes::Black, 0, 0);

 rc = get_ClientRectangle();
 rc.Width -= 1;
 rc.Height -= 1;

 grfx->DrawLine(Pens::Red, 0, 0, rc.Width, rc.Height);

 grfx->DrawEllipse(Pens::Blue, rc);

void HelloWorld::OnResize(EventArgs *ea)

// Hack avoids including <windows.h>

int __stdcall WinMain(int, int, char *pszCmd, int)
 std::string cmdLine(pszCmd);

 if ( cmdLine.find("window") != std::string::npos )
  return 0;

 else if ( cmdLine.find("console") != std::string::npos )
  return 0;

  return -1;

// po2.h header

#include <string>

#using <System.dll>
#using <mscorlib.dll>
#using <System.Drawing.dll>
#using <System.Windows.Forms.dll>

using namespace System;
using namespace System::IO;
using namespace System::Drawing;
using namespace System::Windows::Forms;
using namespace System::ComponentModel;
using namespace System::Runtime::InteropServices;

[ DllImport("KERNEL32.dll", EntryPoint="AllocConsole",
CallingConvention=CallingConvention::StdCall) ]
extern "C" unsigned short int AllocConsole(void);

[ DllImport("KERNEL32.dll", EntryPoint="AttachConsole",
CallingConvention=CallingConvention::StdCall) ]
extern "C" unsigned short int AttachConsole(int);

[ DllImport("KERNEL32.dll", EntryPoint="GetStdHandle",
CallingConvention=CallingConvention::StdCall) ]
extern "C" int GetStdHandle(int);

public __gc class HelloWorld : public Form

    static void Main();
    static void Main2();


     void OnPaint(PaintEventArgs __gc *);
     void OnResize(EventArgs __gc *);

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