Managed C++/CLI

Re: L"" or "" Strings [modified]

16-Jul-07 12:39

Cool!

I have't used forms yet, but I filed that away for future reference.

Thanks!
Mark

Mark Salsbery
Microsoft MVP - Visual C++

"Great job team! Head back to base for debriefing and cocktails."

L”” or to “” Strings

earlgraham16-Jul-07 9:22

earlgraham

16-Jul-07 9:22

When you see System::String used with “xxx” in some text or example you almost always see the ‘L’ macro in from of the text (L”xxx”). However if I do not use the ‘L’, It seems to have no affect to my String values. Am I missing something?

String ^MyText = "Blah";
//or
String ^MyOtherText = L"Blah";

Same right?

Programmer
Glenn Earl Graham
Austin, TX

Mark Salsbery16-Jul-07 9:43

16-Jul-07 9:43

I don't agree with my own reply Smile | :)

I think the compiler now automatically uses the appropriate type when it knows the context.

String ^MyText = "Blah";

The literal "Blah" ends up in the assembly metadata as a CString^, just as using the 'S'
prefix did in VS2003.

hmm - maybe I need to look in the MSIL to see if there's a difference Smile | :)

Mark

-- modified at 15:55 Monday 16th July, 2007

Mark Salsbery
Microsoft MVP - Visual C++

"Great job team! Head back to base for debriefing and cocktails."

iddqd51516-Jul-07 10:55

iddqd515

16-Jul-07 10:55

Its the same MSIL whether you use L or not.

Mark Salsbery16-Jul-07 12:21

16-Jul-07 12:21

Cool! Thanks for saving me the time Wink | ;)

Cheers!
Mark

Mark Salsbery
Microsoft MVP - Visual C++

"Great job team! Head back to base for debriefing and cocktails."

G Haranadh16-Jul-07 20:02

G Haranadh

16-Jul-07 20:02

Mark Salsbery wrote:
String ^MyText = "Blah"

Hi, What this "^" cap symbol represents? where it is useful?

Nice talking to you. Blush | :O

If you judge people, you have no time to love them. -- Mother Teresa

iddqd51517-Jul-07 3:33

iddqd515

17-Jul-07 3:33

Its a handle. Used like a pointer for pointing to managed objects on the managed heap. Its pretty fundamental to writing managed code with C++/CLI.

I am new to programming

Red Lake16-Jul-07 8:54

Red Lake

16-Jul-07 8:54

Hello,
I have never programmed before and I am trying to teach myself C during downtimes at work. The first program that I did is the Hello World program. I am using the Compiler Dev C++ and when I run the program it closes immediately and I don't the chance to see it. Can Anyone help me. This is what I have for code:

#include <iostream>
using namespace std;

int main (void)
{
cout << "Hello World!";
return 0;
}

Steve Vondras
Red Lake Nation
MIS Tech
svondras@redlakenation.org

Wes Aday16-Jul-07 9:33

Wes Aday

16-Jul-07 9:33

I am going to go out on a limb here and say that you mean that a console window displays then immediately closes. I believe that you need a getch() before the return.

Why is common sense not common?

Never argue with an idiot. They will drag you down to their level where they are an expert.

Sometimes it takes a lot of work to be lazy

Red Lake16-Jul-07 9:48

Red Lake

16-Jul-07 9:48

Thanks for the quick reply, it worked right away. I have seen the code for this hello world in several different places, but I have never seen the getch(). Why is that?

Steve Vondras
Red Lake Nation
MIS Tech
svondras@redlakenation.org

Wes Aday16-Jul-07 9:55

Wes Aday

16-Jul-07 9:55

The code as you wrote in your original message did a cout and then returned. It did that. Returning meaning that the program was finished so that the window closed. Getch() simply waits for keyboard input before the program continues.

If you were to run your program from a command prompt, you would not need the getch().

Why is common sense not common?

Never argue with an idiot. They will drag you down to their level where they are an expert.

Sometimes it takes a lot of work to be lazy

Paul Conrad16-Jul-07 10:07

Paul Conrad

16-Jul-07 10:07

Like Wes said, it closes right after running if it is a console app. If you run it from a Dos box, it'll stay there with the Dos prompt when done.

Good luck on learning C++. Dev C++ is nice, have you looked at the Express Editions of C++/C#?

"Any sort of work in VB6 is bound to provide several WTF moments." - Christian Graus

Red Lake16-Jul-07 10:22

Red Lake

16-Jul-07 10:22

If you mean Visual Express, yes I have. I am thinking of getting a version of it if the price is right. Thanks for the response.

Steve Vondras
Red Lake Nation
MIS Tech
svondras@redlakenation.org

Re: Registering Window Class

Paul Conrad16-Jul-07 10:52

Paul Conrad

16-Jul-07 10:52

Red Lake wrote:
I am thinking of getting a version of it if the price is right.

You should. I think it is still FREE Big Grin | :-D

There was a way to get Visual Studio Standard Edition for "free" ( just pay the shipping and handling ) from Microsoft by watching two of their labcasts. I think it expired at the end of June. I'd keep an eye out for that.

"The clue train passed his station without stopping." - John Simmons / outlaw programmer

Registering Window Class

john john mackey16-Jul-07 8:38

john john mackey

16-Jul-07 8:38

I need some help...
I have a dialog based app and I want to register the (window) class. So many question have I.

1) where do I put my code for registering the class?
2) do I use RegisterClass, RegisterClassEX, AfxRegisterClass, AfxRegisterClassEx?
3) REASON: interprocess communication using Windows Messaging

I have some legacy code that i'm looking at for an example, but it is a Doc-View type and it appears easier as it has the registeration inside the PreCreateWindow( ) function - see below

Thanks,
Johnny

<br />
#define MYAPPWINDOW_CLASSNAME	_T("MyOwnWindow")	//window class name<br />
<br />
BOOL CMainFrame::PreCreateWindow(CREATESTRUCT& cs)<br />
<br />
	//register MYAPPWindow class if not already registered<br />
	WNDCLASS  wndcls;<br />
	HINSTANCE hInst = AfxGetInstanceHandle();<br />
<br />
	if( !(::GetClassInfo(hInst, MYAPPWINDOW_CLASSNAME, &wndcls)) )<br />
	{<br />
	   if( ::GetClassInfo( hInst, cs.lpszClass, &wndcls ))<br />
	   {<br />
	      wndcls.lpszClassName = MYAPPWINDOW_CLASSNAME;<br />
	      wndcls.hIcon = LoadIcon(hInst, MAKEINTRESOURCE(IDR_MAINFRAME));<br />
	      if( !AfxRegisterClass(&wndcls) )<br />
	      {<br />
	         AfxThrowResourceException();<br />
	         return FALSE;<br />
	      }<br />
	   }<br />
	   else<br />
	   {<br />
	      AfxThrowResourceException();<br />
	      return FALSE;<br />
	   }<br />
	}<br />
<br />
	cs.lpszClass = MYAPPWINDOW_CLASSNAME;<br />

Mark Salsbery16-Jul-07 9:51

Re: Registering Window Class

16-Jul-07 9:51

As a general rule, use the Afx functions in an MFC app and use the API functions in a Win32 app.

You can put the call anywhere as long as it gets called before attempting to create a window of
the registered class. PreCreateWindow() is fine.

Mark

Mark Salsbery
Microsoft MVP - Visual C++

"Great job team! Head back to base for debriefing and cocktails."

john john mackey16-Jul-07 11:52

john john mackey

16-Jul-07 11:52

I am still lost and now frustrated (with MSDN documentation on the matter.)

What I have is a dialog based app and inside my OnInitDialog(), I have put what is the beginnings of registering my window class..

When I do this, i get the runtime "warning" that "A required resource was unavailable." (i trace this to the second call to ::GetClassInfo() as I don't know how to properly supply the 2nd parameter.)

<code>BOOL CMyDlg::OnInitDialog()
{
	CDialog::OnInitDialog();
//yadda yadda yadda

	// register MyOwnApp window class if not already registered

	WNDCLASS	wndcls;
	HINSTANCE hInst = AfxGetInstanceHandle();

	if( !(::GetClassInfo(hInst, MYOWNAPP_CLASSNAME, &wndcls)) )
	{
		if( ::GetClassInfo( hInst, NULL, &wndcls ))
		{
			wndcls.lpszClassName = MYOWNAPP_CLASSNAME;
//			wndcls.hIcon = LoadIcon(hInst, MAKEINTRESOURCE(IDR_MAINFRAME));
			if( !AfxRegisterClass(&wndcls) )
			{
				AfxThrowResourceException();
				return FALSE;
			}
		}
		else
		{
			AfxThrowResourceException();
			return FALSE;
		}
	}

	return TRUE;  // return TRUE  unless you set the focus to a control
}
</code>

Re: Registering Window Class

Mark Salsbery16-Jul-07 12:28