Re: Forms and VC++

"blangela" <Bob_Langelaan@telus.net> wrote in message
news:1163781759.663127.179490@h48g2000cwc.googlegroups.com...


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++.

<aside>
Whether the rest of this post will be useful or noise in an open question.
:-)
</side>

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
C++.

Regards,
Will

#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 )
  AllocConsole();

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

 Console::WriteLine("Hello, world!");
}

HelloWorld::HelloWorld()
{
 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)
{
 Invalidate();
}

// Hack avoids including <windows.h>

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

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

 else if ( cmdLine.find("console") != std::string::npos )
 {
  HelloWorld::Main2();
  return 0;
 }

 else
  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
{
 public:

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

 protected:

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