Managed C++/CLI

Re: Warnings in c++/cli that make me a lot of headache

31-Aug-07 9:25

The only way I could get native static objects to work in managed code was to place them inside of static functions or static methods. For example:

#pragma managed(push, off)
using std::wstring;
 
class Foo
{
public:
 
	static const wchar_t* State(const wchar_t* value = 0)
	{
		static std::wstring state= L"";
 
		if (value != 0)
			state = value;
 
		return state.c_str();
	}
 
};
#pragma managed(pop)
 
using namespace System;
 
int main(array<System::String ^> ^args)
{
	String^ str1 = gcnew String(Foo::State());
 	
	Foo::State(L"Hello!");
 
	String^ str2 = gcnew String(Foo::State());
 
	Console::WriteLine(str1);
	Console::WriteLine(str2);
 	
    return 0;
}

"We make a living by what we get, we make a life by what we give." --Winston Churchill

hansipet1-Sep-07 8:55

hansipet

1-Sep-07 8:55

Thank you very much!!!

Re: Warnings in c++/cli that make me a lot of headache

George L. Jackson30-Aug-07 3:51

mixed types are not supported?

30-Aug-07 3:51

Issue #2: Have you tried manually boxing the zero?

"We make a living by what we get, we make a life by what we give." --Winston Churchill

Rui A Sousa29-Aug-07 6:45

Rui A Sousa

29-Aug-07 6:45

Hello!

I have this code:

(...)
static double U[5];
(...)

And, when i compile i see this error:

error C4368: cannot define 'U' as a member of managed 'bojoo::Class1': mixed types are not supported

Frown | :(

How i fix it?

Thank´s!

Rapbs

Re: mixed types are not supported?

led mike29-Aug-07 7:06

Re: mixed types are not supported?

29-Aug-07 7:06

Rui A Sousa wrote:
How i fix it?

I would like to clarify what you are asking for. Do you want someone to tell you how to fix the code or, do you want to understand the issue so that it will never be a problem for you again?

Mark Salsbery29-Aug-07 8:07

Making Dialog Boxes Modal

29-Aug-07 8:07

One feature in Visual Studio I find useful is the pressing the F1 key on error messages I don't
understand Poke tongue | ;-P

For example - your error shows me:

"You cannot embed a native data member in a CLR type.

You can, however, declare a pointer to a native type and control its lifetime in the constructor
and destructor and finalizer of your managed class (see <mshelp:link tabindex="0" keywords="0d09d3f1-13a0-4041-8178-402aad667edd">Destructors and Finalizers in Visual C++
for more information)."

Cheers,
Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

gunner_uk200029-Aug-07 5:58

gunner_uk2000

29-Aug-07 5:58

2 classes which are dialogues.

On the 1st dialog, I have button that when pressed opens another dialog. I can't work out how to make the second one modal.

I'm calling the second Dialog boxes show() method in the DlgProc method as below.

LRESULT CALLBACK ExodusDisplayOptions::DlgProc(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam){<br />
	//TODO: Comment and clean up.<br />
	switch(message)<br />
    {<br />
		case WM_INITDIALOG:<br />
		{<br />
			//do some stuff<br />
		}<br />
		break;<br />
        case WM_DESTROY:<br />
            PostQuitMessage(0);<br />
		break;<br />
		case WM_COMMAND:<br />
		{<br />
			switch (LOWORD(wParam))<br />
			{<br />
			case WM_CLOSE:				<br />
				return (TRUE);<br />
			break;<br />
			case IDC_CLOSE:<br />
				EndDialog(hDlg, LOWORD(wParam));<br />
				return (TRUE);<br />
			break;<br />
			case IDC_BUTTONDISPLAY:<br />
				ExodusHazardDisplayOptions *haz = new ExodusHazardDisplayOptions(m_this, m_opts);<br />
				bool i = haz->Show();<br />
			break;<br />
<br />
<br />
			}<br />
<br />
			<br />
		}	<br />
        break;<br />
        default:<br />
            return DefDlgProc(m_this, message, wParam, lParam);<br />
    }<br />
    return 0;<br />
}

Any ideas?

Re: Making Dialog Boxes Modal

Mark Salsbery29-Aug-07 8:16

Can not convert from short __gc* to short*

29-Aug-07 8:16

gunner_uk2000 wrote:
Any ideas?

You're in the wrong forum Smile | :)

What does "haz->Show()" do? Is it creating a modal dialog? For a modal dialog
you need to call one of the DialogBox___() APIs.

Off topic... the "case WM_CLOSE" in response to WM_COMMAND looks suspicious.

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Thanks for all the fish28-Aug-07 23:41

Thanks for all the fish

28-Aug-07 23:41

Hi All

I am creating a managed wrapper class for a c++ unmanaged class.While I am calling a function in managed class and passing a short paramater as reference

1.short MCDPTAdminClass::listPrinters() //managed class
2.{
3. m_CDPTAdminClass->listPrinters(&numPrintersFound);
//m_CDPTAdminClass object of unmanaged class and short numPrintersFound
return numPrintersFound;

}

I am getting an error "Can not convert from short __gc* to short*" at line "3"
Can anyone help me to resolve this problem .

thanks in advance

led mike29-Aug-07 5:16

29-Aug-07 5:16

Thanks for all the fish wrote:
Can anyone help me to resolve this problem

I would like to clarify what you are asking for. Do you want someone to tell you how to fix the code or, do you want to understand the issue so that it will never be a problem for you again?

Mark Salsbery29-Aug-07 8:17

29-Aug-07 8:17

Thanks for all the fish!

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

George L. Jackson29-Aug-07 12:05

29-Aug-07 12:05

Mark Salsbery wrote:
Thanks for all the fish!

Does that have some kind of religious significance?

"We make a living by what we get, we make a life by what we give." --Winston Churchill

Mark Salsbery29-Aug-07 12:45

29-Aug-07 12:45

George L. Jackson wrote:
Does that have some kind of religious significance?

Only in my religious commitment to keeping led mike's fish-filet analogy alive!

Smile | :)

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

George L. Jackson29-Aug-07 13:00

Calling into .NET Class Lib from a C++ app

29-Aug-07 13:00

HeHe! I saw the original posts!

"We make a living by what we get, we make a life by what we give." --Winston Churchill

concoran28-Aug-07 21:04

concoran

28-Aug-07 21:04

Is it possible to call into a .NET class library from a VC60 C++ app? If yes, how?

I wanted to create a middle layer between C++ app and .NET class library - sort of a wrapper for .NET class library. Towards that end, in VS2005, I created a C++ Win32 Dll. I have turned on CLR option from Project->Properties>Configuration. But in this project, I couldn't figure out how do I instantiate ClassLibrary and make calls into it. Can someone please enlighten?

Thanks.

None

Re: Calling into .NET Class Lib from a C++ app

led mike29-Aug-07 5:13

Re: Calling into .NET Class Lib from a C++ app

29-Aug-07 5:13

concoran wrote:
Can someone please enlighten?

It sounds like this is your initial use of C++/CLI? If so I recommend learning about it first before you approach your project. There are almost endless articles, tutorials and sample/example projects available here and on MSDN to educate you about the power of C++/CLI.

concoran30-Aug-07 14:05

concoran

30-Aug-07 14:05

Hi Led,

Yes, I am new to CLI, but not to C++. I am also new to Codeproject. Can you pls point to where I can find articles on this website?

Thanks in advance.

None

Re: Calling into .NET Class Lib from a C++ app

led mike31-Aug-07 4:20

31-Aug-07 4:20

concoran wrote:
Can you pls point to where I can find articles on this website?

On the "Articles" menu (it's between "Hellp" and "Message Boards") click the "Site Directory" link

C++/CLI Zooming

BuckBrown28-Aug-07 12:45

BuckBrown

28-Aug-07 12:45

Hi, I'm using Visual Studio 2005 C++/CLI. I have been surfing for information on zooming using CLI. The SetWindowsExt() and SetViewportExt() functions do not seem to be available any more. If anyone has a link to an article or can at least point me in the right direction it would really help.

Thanks,

Buck

Luc Pattyn28-Aug-07 12:49

Luc Pattyn

28-Aug-07 12:49

Hi Buck,

if you want to modify things you paint yourself (say inside OnPaint),
then you can use the transform methods of the Graphics class; they let
you set translation, rotation, scaling (or an enire matrix), then do
the paint stuff as before.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

this weeks tips:
- make Visual display line numbers: Tools/Options/TextEditor/...
- show exceptions with ToString() to see all information
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Re: C++/CLI Zooming [modified]

BuckBrown29-Aug-07 13:02

BuckBrown

29-Aug-07 13:02

Hi Luc,

Here is the code that allows me to use the mouse to draw a rectangle around an area of the display that I want to fill the display with, hence zooming. The aspect ratio is kept constant so if the rectangle is too high or too wide then it adjust the heighth or width accordingly. The Translate function positions the origin. The Scale function sets the scaling in the x and y directions. This TransformPointsExample function is called from OnPaint(PaintEventArgs^ e).

private: void TransformPointsExample(PaintEventArgs^ e)
{
float aspect_ratio = (float)nDisplayHeight / nDisplayWidth;
float zoombox_height = (float)zoomRectEndPos.Y - zoomRectStartPos.Y;
float zoombox_width = (float)zoomRectEndPos.X - zoomRectStartPos.X;

if(zoombox_height / zoombox_width > aspect_ratio)
zoombox_width = zoombox_height / aspect_ratio;
else
zoombox_height = zoombox_width * aspect_ratio;

float y_scale = (float)nDisplayHeight / zoombox_height;
float x_scale = (float)nDisplayWidth / zoombox_width;

Matrix^ myMatrix = gcnew Matrix();
myMatrix->Translate(-(float)zoomRectStartPos.X, -(float)zoomRectStartPos.Y);
myMatrix->Scale(x_scale, y_scale, MatrixOrder::Append);
e->Graphics->Transform = myMatrix;
}

Buck

Luc Pattyn29-Aug-07 13:17

Luc Pattyn

29-Aug-07 13:17

Hi Buck,

thanks for the update. Any questions?

You did not have to create a Matrix, Graphics.TranslateTransform() plus
Graphics.ScaleTransform() would have given same result and avoid an object.
As it is now you should do myMatrix.Dispose() when OnPaint is done!

[CORRECTION] See the next two replies by Mark: in C++/CLI Dispose() can not be
called directly, but a delete is in order [/CORRECTION]

Smile | :)

-- modified at 5:28 Thursday 30th August, 2007

Luc Pattyn [Forum Guidelines] [My Articles]

Mark Salsbery29-Aug-07 14:18

29-Aug-07 14:18

Luc Pattyn wrote:
you should do myMatrix.Dispose() when OnPaint is done!

Or for C++ consistency, use

delete myMatrix;

Smile | :)

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]