Managed C++/CLI

How to use Callback interface from unmanaged code in Managed C++

28-Oct-11 1:47

phil.o wrote:
Never put your email address ...

I have stopped warning people about this as chances are they are doing it all over the internet.

Unrequited desire is character building. OriginalGriff
I'm sitting here giving you a standing ovation - Len Goodman

Re: My vote of 1

phil.o28-Oct-11 3:08

phil.o

28-Oct-11 3:08

I didn't, yet Wink | ;)

dadagiri12322-Oct-11 1:14

dadagiri123

22-Oct-11 1:14

How to get callback in managed C++/CLI from unmanaged code, my managed code class has implemented unmanaged COM interface ,how shall i do that

Re: How to use Callback interface from unmanaged code in Managed C++

Adam Roderick J26-Oct-11 22:28

Adam Roderick J

26-Oct-11 22:28

i think this will help

<a href="http://blogs.microsoft.co.il/blogs/alon/archive/2007/05/29/Native-Callback.aspx">http://blogs.microsoft.co.il/blogs/alon/archive/2007/05/29/Native-Callback.aspx</a>[<a href="http://blogs.microsoft.co.il/blogs/alon/archive/2007/05/29/Native-Callback.aspx" target="_blank" title="New Window">^</a>]

Величие не Бога может быть недооценена.

-- modified 3-Jan-12 4:58am.

Re: How to use Callback interface from unmanaged code in Managed C++

Richard MacCutchan27-Oct-11 0:02

Re: How to use Callback interface from unmanaged code in Managed C++

27-Oct-11 0:02

Your link is not clickable.

Unrequited desire is character building. OriginalGriff
I'm sitting here giving you a standing ovation - Len Goodman

Bob Ciora16-Nov-11 1:59

Bob Ciora

16-Nov-11 1:59

Just pull out the useful part from the link.

http://blogs.microsoft.c.il/blogs/alon/archive/2007/05/29/Native-Callback.aspx

I genrally use method #4 because many of my callbacks are in the form of interface classes (e.g. "ICallback"). I create a "bridge" class (unmanaged class built in a managed dll) with an implementation of the unmanaged callback that marshals any parameters to the managed world, then calls a similar method on a gcroot'ed handle to a managed interface.

Bob Ciora

How and which technology (.NET-WinForms,C++-MIDI MFC based) is the best to use for reading and writing COM Port data?

glitteringsound11-Oct-11 22:55

glitteringsound

11-Oct-11 22:55

I need to solve a problem for reading and writing COM Port data from MIDI application.

1)The software must be able to handle multiple MIDI In and MIDI Out ports simultaneously sending and receiving MIDI data without choking off performance for the application (this will include audio as well).

I am using a modified version of the old Mabry MIDIIO already, MFC COM server in a shared .dll, written in c++. It is currently be compiled down into an .ocx and requires COM registration. It is working in the Visual Studio 2008 environment

But A total rewrite or different solution is a viable option but of course with the fastest, most inexpensive and easiest to maintain solution.

Here are the questions:

1)What direction would you recommend COM control or .net control, .dll, multi-thread, something else and why? If anybody having idea about MABRY Control, Do you think the Mabry control could be reworked into my new solution or would it be better to just take a totally different direction?

2)What is the recommendation? an unmanaged or managed solution?

Regards Usman

printer driver

dufduf7-Oct-11 21:11

dufduf

7-Oct-11 21:11

Hi,
This is my first post on this forum so please bear with me.
I'm trying to send epson fx printer code to the dot-matrix printer using function:

C++

char* cSendBuf = "\0x1bl\0x03"; //set left margin - ESC 1 n
RawDataToPrinter( L"\\\\AGO\\Oki ML 520 Elite (IBM)", cSendBuf, strlen(cSendBuf) );

And I don`t know where to put the text "sample text"? Just behind the code: the text does not print. Before the code: text will not be set to the column specified in the code.

C++

char* cSendBuf = "\0x1bl\0x03\sample text";
char* cSendBuf = "sample text\0x1bl\0x03";

How it should be assigned to a pointer value to char* cSendBuf?
Thanks.

Re: printer driver

Luc Pattyn8-Oct-11 4:48

Luc Pattyn

8-Oct-11 4:48

Hi,

in my experience printing on an EPSON matrix printer doesn't need anything special, it works like all other printers, which means: create a class that derives from PrintDocument, and all is good. That is, assuming you are using the .NET Framework. If you don't, your code isn't managed C++ and your question is in the wrong forum.

If, for whatever reason, you do need to generate ESC/P commands yourself, the language specs can be found with Google, here[^] is one candidate; I trust there are some working examples included. And if you still have questions about it, you still would be (slightly) better of in another forum, probably "Hardware and Devices" (don't hold your breath).

Smile | :)

Luc Pattyn [My Articles] Nil Volentibus Arduum
iSad

[Need Help] some thing about output

Mike@Shanghai3-Oct-11 23:58

3-Oct-11 23:58

Hi, everyone. I got some trouble with c++.
IDE: Visual C++ 2010 express
win32 console application

The purpose of this program is: if I input a string such as: "CS101 C++ PROGRAMMING", the string what i've inputed will appear on the screen.

The following is my codes.

#include "stdafx.h"
#include <string>
using std::string;
using std::getline;

#include <iostream>
using std::cin;
using std::cout;
using std::endl;

class GradeBook
{

private:
string courseName;

public:
GradeBook( string name )
{
setCourseName( name );
}

void setCourseName( string name )
{
courseName = name;
}

string getCourseName()
{
return courseName;
}

void displayMessage()
{
cout << "The courseName: " << getCourseName()<<"!" << endl;

}

};

int _tmain(int argc, _TCHAR* argv[])
{

for( int i = 0; i < 2; i ++ )
{ string name;
cout << "Input Grade book [" << i + 1 << "]" << endl;
getline( cin, name );

GradeBook myGradeBook( name );
myGradeBook.getCourseName();

}

return 0;
}

In this program, I've defined a class named GradeBook who has four member functions. In the main function, if i used "myGradeBook.getCourseName()" there will be no result on the screen. If I use "myGradeBook.displayMessage()", the result will appear on the screen.

who can tell me why. Thank you.

Mike@Shanghai4-Oct-11 0:04

4-Oct-11 0:04

why can't i edit the string "#include<iostream>" and "#include<string> "on this page?

Mike@Shanghai4-Oct-11 0:49

4-Oct-11 0:49

I got the answer
the statment should be cout << myGradeBook.getCourseName();
Then the result will be on the screen!

WOW!

Richard MacCutchan4-Oct-11 2:28

4-Oct-11 2:28

You could also have used your displayMessage() function, which does the same thing for you. Remember the definition of your getCourseName() function, is just to return the string containing the name, so you still need to pass that to a function that will display it, or, as in this case, pass it directly to cout.

Unrequited desire is character building. OriginalGriff

Mike@Shanghai4-Oct-11 3:05

How can program tell that itself is running as admin?

4-Oct-11 3:05

Thank you.

Brandon-X120001-Oct-11 6:40

Brandon-X12000

1-Oct-11 6:40

Hello people I have the following the code written in C++, converted from Vb.net to C++ from a program, the following code tells the user via message box if the program is running as an admin, see below

C++

Object ^identity = WindowsIdentity::GetCurrent();
WindowsPrincipal ^principal = gcnew WindowsPrincipal(identity);
bool isElevated = principal->IsInRole(WindowsBuiltInRole::Administrator);

try
    {
    if (isElevated == true)
    {
    }
    else
    {
        MessageBox::Show("WARNING: Program not running as administrator!", "Credential Error", MessageBoxButtons::OK, MessageBoxIcon::Error);
    }
    }
catch (Exception ^ex)
{
    MessageBox::Show("This program cannot run as performed because your system does not support admin rights, program now terminating from computer memory.", ".Net Framework Error", MessageBoxButtons::OK, MessageBoxIcon::Error);
    Environment::Exit(1);
}

When this block of code was executed with my program, I get the following error message (In double quotations):

"error C2664: 'System::Security::Principal::WindowsPrincipal::WindowsPrincipal(System::Security::Principal::WindowsIdentity ^)' : cannot convert parameter 1 from 'System::Object ^' to 'System::Security::Principal::WindowsIdentity ^'"

the remaining error messages are (In double quotations):

"1> No user-defined-conversion operator available, or
1> Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast"

Could anyone point out something that I could edit that could make the compiler accept or work, any suggestions or personal solutions are appreciated Smile | :)

Re: How can program tell that itself is running as admin?

Luc Pattyn1-Oct-11 6:58

Luc Pattyn

1-Oct-11 6:58

Brandon-hbx12000 wrote:
Object ^identity = WindowsIdentity::GetCurrent();

The problem is in the very first word. Why would you "anonimize" whatever it is GetCurrent() returns? Use real types where ever you can.

Smile | :)

Luc Pattyn [My Articles] Nil Volentibus Arduum

Re: How can program tell that itself is running as admin?

Brandon-X120001-Oct-11 7:13

Brandon-X12000

1-Oct-11 7:13

thank you

Re: How can program tell that itself is running as admin?

Luc Pattyn1-Oct-11 7:31

Luc Pattyn

1-Oct-11 7:31

You're welcome.

Smile | :)

Luc Pattyn [My Articles] Nil Volentibus Arduum

Re: How can program tell that itself is running as admin?

Richard MacCutchan1-Oct-11 7:02

Re: How can program tell that itself is running as admin?

1-Oct-11 7:02

You have stored the return from your call to WindowsIdentity::GetCurrent() as an object reference. You are then sending that object reference to the WindowsPrincipal() constructor, which expects a WindowsIdentity reference as documented here[^]. The compiler is complaining because it does not feel able to promote an object reference to a higher level. Save your WindowsIdentity object as a WindowsIdentity reference.

Unrequited desire is character building. OriginalGriff

Brandon-X120001-Oct-11 7:13

Brandon-X12000

1-Oct-11 7:13

thank you

Re: How can program tell that itself is running as admin?

Richard MacCutchan1-Oct-11 7:36