Managed C++/CLI Discussion Boards

Nik Vogiatzis3-Feb-04 20:30

3-Feb-04 20:30

hi all...

ok, ill get to the nuts and bolts of the problem...

i keep getting a C2259 error ('class' : cannot instantiate abstract class due to following members: )

now the class it is complaining about is one that instantiates IDataParameterCollection and ArrayList... specifically:

public __gc class NewSQLParameterCollection: public ArrayList, public IDataParameterCollection{};

and the function it is complaining about is this one...

bool  Contains(String *p)<br />
{<br />
   //if IndexOf returns a value less than 0, then we know that<br />
   //the item doesn't exist<br />
   if (this->IndexOf(p) >= 0)<br />
      return true;<br />
   else<br />
      return false;<br />
}

(umm, and before you say that i am missing the NewSQLParameterCollection:: indentifier, i should mention that i am inlining the call within the class header... Smile | :)

)

now the problem occurs when in a subsequent class i call the following

function test::sometest()<br />
{<br />
 NewSQLParameterCollection *p = new NewSQLParameterCollection(S"Name", Object);<br />
}

it says that it can't find the function (as in bool Contains(...)) above, but as you can see, it's there...

any ideas?

this is for an open source C++.NET MySQL driver i am writing, so any help would be GREATLY appreciated...

cheers and thanks
nik

Nik Vogiatzis
PhD Candidate: University of South Australia
+++++++++++++++++++++++++++
Developing new generation Traffic Micro-simulation Tools for Traffic Engineers
em: nikolaos.vogiatzis@unisa.edu.au

Re: HELP!!! compiler seems confused...

Roger Stewart5-Feb-04 6:53

Roger Stewart

5-Feb-04 6:53

You probably need to uniquely identify your implementation.

bool IDataParameterCollection::Contains(String *p)
{
    //if IndexOf returns a value less than 0, then we know that
    //the item doesn't exist
    if (this->IndexOf(p) >= 0)
        return true;
    else
        return false;
}

Roger Stewart
"I Owe, I Owe, it's off to work I go..."

Re: HELP!!! compiler seems confused...

Nik Vogiatzis5-Feb-04 9:51

Nik Vogiatzis

5-Feb-04 9:51

hi roger...

yeah, already tried that, and then it comes up with:

MySqlParameterCollection.h(23) : error C3244: 'IDataParameterCollection.Contains' : this method was introduced by 'System::Data::IDataParameterCollection' not by 'System::Data::IDataParameterCollection'<br />

which is strange... however, you did inspire me and i tried this:

bool  MySqlParameterCollection::Contains(String *p)<br />
{<br />
   //if IndexOf returns a value less than 0, then we know that<br />
   //the item doesn't exist<br />
   if (this->IndexOf(p) >= 0)<br />
      return true;<br />
   else<br />
      return false;<br />
}

and that seems to have removed one of the 'errors', i just need to workout why the same technique is not working for __property bool get_IsNullable(void) for MySqlParameter, and i will have it! Big Grin | :-D

cheers and thanks for your assistance roger...
nik

Nik Vogiatzis
PhD Candidate: University of South Australia
+++++++++++++++++++++++++++
Developing new generation Traffic Micro-simulation Tools for Traffic Engineers
em: nikolaos.vogiatzis@unisa.edu.au

Compile New Form Control

Skute3-Feb-04 2:39

Skute

3-Feb-04 2:39

Hi,

If i made a new "TextBox" for example, based on the old Forms::TextBox, how could i package it up into a .dll so that i could link to it in other applications?

Also, is it best to put it into the System::Windows::Forms namespace? ie:

<br />
namespace System<br />
{<br />
	namespace Windows<br />
	{<br />
		namespace Forms<br />
		{<br />
			class MyTextBox : public TextBox<br />
			{<br />
				...<br />
			};<br />
		};<br />
	};<br />
};<br />

Skute

ON_UPDATE_UI problem

Keith Halligan3-Feb-04 0:08

Keith Halligan

3-Feb-04 0:08

Im created a toolbar that allows one of the four buttons in the toolbar to be set at a time, by maintaining a enum constant in the CDocument derived class. Now the UPDATE_UI functions only execute on startup and not all of the time like there supposed to.
Im changing other variables in the doc class else where, is there something I should be setting when i alter these variables.

Please Help

Keith

How to add a function that has both external and internal name into a ActiveX?

ray_li2-Feb-04 8:37

ray_li

2-Feb-04 8:37

Hi,

I'm developing a Activex with .net C++, i try to add a method that has both external and internal name into this activex, so that I can call this method ourside of this activex. but I can notfind a way to do this job as we do this with classwizard in VC.

So pls help me, if you know how to solve this problem?
thx.

Ray Confused | :confused:

Crashing of .NET IDE when placing custom designer control in toolbox

Tonkuz2-Feb-04 2:35

Tonkuz

2-Feb-04 2:35

:(Hello Friends,

We are making a VC++ . net designer control by wrapping an mfc control we are already having.But when I place the control in the toolbox, by selecting the control dll , there is some unhandled exception happens and the proces is terminated.This problem is not happening when I place the control by copying and pasting form some existing samples using this control ,made previously by another developer.That is once this control is copied and placed on some design form, there is no problem in adding this control to the tool box.
while debugging I could see the _DllMainCRTStartup() function is repeatedly called .Each time DllMainCRTStartup is called the application slows down and finally an unhandled exception is being thrown.
We are using the .NET Framework 1.0 version 1.0.3705
and IDE 2002 version 7.0.9466
Please help me...Thankz in advance
Sathyan

Re: Crashing of .NET IDE when placing custom designer control in toolbox

Anonymous5-Feb-04 17:05

Anonymous

5-Feb-04 17:05

I was trying to add a custom contorl to the tool box , the IDE was crashed .I tried with a simple class that derived form control that too could not be added to the toolbox when placed within this assembly(same result the ide was crashed).
The call stack is like the following.

ntdll.dll!77f827e8()
kernel32.dll!77e86a3d()
user32.dll!77e2481d()
user32.dll!77e24600()
user32.dll!77e3a1ab()
ntdll.dll!77fa032f()
user32.dll!77e1569d()
msenv.dll!50080965()
msenv.dll!50080939()

the error message got was
Unhandled exception at 0x096cb860 in devenv.exe: 0xC0000005: Access violation reading location 0x096cb860.

is it due to some problem with the dll since it was made by wrapping an mfc control..
Friends plz tell me due to what reason the this is happening..
Sathyan

Getting an HINSTANCE in a managed C++ dll

dabs2-Feb-04 2:09

dabs

2-Feb-04 2:09

Even though the traffic seems to be relatively small here, I'll go ahead and ask anyway. I'm writing a managed dll in C++ (actually it's an NUnit test dll), and I need to be able to get the dll's HINSTANCE - to either load resources or to call GetModuleFileName( ). So far I've tried the following:

<br />
_pModule->get_m_hInstResource( )<br />
_pModule->get_m_hInst( )<br />
::GetModuleHandle( NULL )<br />
AfxGetResourceHandle( )<br />
AfxGetInstanceHandle( )<br />

But no luck. They just return NULL. Has anyone had any similar problem in the past, and if so, what did you do to solve it?

Daníel

Wenn ist das Nunstück git und Slotermeyer? Ja! Beierhund das oder die Flipperwaldt gersput!

Re: Getting an HINSTANCE in a managed C++ dll

Anonymous13-Feb-04 12:28

Anonymous

13-Feb-04 12:28

Because its a managed DLL, I think the best approach would be to
get at the Resources via
using System::Reflection

__gc Assembly* Assembly;
__gc ???* [] mResults; //Don't recall the return type.

mResult[] = Assemble->GetExecutingAssembly()->GetLoadedModules(true);

And then walk the array of objects filtering for IsResource() property.

Casting of a Object * to a Enum value question??

araelgig2-Feb-04 1:27

araelgig

2-Feb-04 1:27

Hi all!

I have a problem with letting the compiler accept the following code, see example below.

I have a logfile that contains statements about variuos actions taken during an installation. The actions are a value of a enum type itemOper = {FileCopy, FileMerge, FolderOk, ...} which is written to the logfile by Enum::GetName(__typeof(itemOper), oper), where oper has one value of the enum type. No FlagAttribute are used.
When i later read the logfile I want to translate the text "FileCopy" back into a value of type itemOper. It works fine in runtime with the debugger and the following code:

Object * item = Enum::Parse(__typeof(itemOper), S"FileCopy");

If i set a breakpoint at a line after this statement the debugger show that the variable item has the value "FileCopy", thats fine!! Now to the problem. The compiler does not allow any cast's or a switch(oper) statement!!!. It does not accept a "if (oper == itemOper::FileCopy)" and so on.

What to do, the base class Enum is usable at some point, but here I'm stuck.
Does anybody know how to "fool" the compiler or does anybody have the right solution??

/Thanks

Re: Casting of a Object * to a Enum value question??

araelgig3-Feb-04 1:08

araelgig

3-Feb-04 1:08

I found the answer!!
I have to unbox the value from the returned Object

itemOper oper = *dynamic_cast<__box itemOper*>(item);

Big Grin | :-D

LNK2005 Error.

adarsh_sebiz1-Feb-04 19:05

adarsh_sebiz

1-Feb-04 19:05

Hi everybody,

I have downloaded latest swfsource form www.sourceforge.com
I am trying to build swfsource using VC++ .NET, but while linking it showing many LNK2005 errors.

I tired /FORCE:MULTIPLE option in Project->Properties->Linker->Command Line, and this option helps me to remove those errors and forcely link swfsource successfully.
This force linking is not generating full swfsource.exe file.

Can anybody suggest me some better solution, which does this linking in normal ways(i.e. without forcefully)?

I am listing down some of those LNK2005 errors that i am getting, below:

Linking...
animate.obj : error LNK2005: _Int64ShllMod32@12 already defined in 8bim.obj
animate.obj : error LNK2005: _Int64ShraMod32@12 already defined in 8bim.obj
animate.obj : error LNK2005: _Int64ShrlMod32@12 already defined in 8bim.obj
annotate.obj : error LNK2005: _Int64ShllMod32@12 already defined in 8bim.obj
annotate.obj : error LNK2005: _Int64ShraMod32@12 already defined in 8bim.obj
annotate.obj : error LNK2005: _Int64ShrlMod32@12 already defined in 8bim.obj
art.obj : error LNK2005: _Int64ShllMod32@12 already defined in 8bim.obj
art.obj : error LNK2005: _Int64ShraMod32@12 already defined in 8bim.obj
art.obj : error LNK2005: _Int64ShrlMod32@12 already defined in 8bim.obj
attributes.obj : error LNK2005: _Int64ShllMod32@12 already defined in 8bim.obj
attributes.obj : error LNK2005: _Int64ShraMod32@12 already defined in 8bim.obj
attributes.obj : error LNK2005: _Int64ShrlMod32@12 already defined in 8bim.obj
avi.obj : error LNK2005: _Int64ShllMod32@12 already defined in 8bim.obj
avi.obj : error LNK2005: _Int64ShraMod32@12 already defined in 8bim.obj
avi.obj : error LNK2005: _Int64ShrlMod32@12 already defined in 8bim.obj
avs.obj : error LNK2005: _Int64ShllMod32@12 already defined in 8bim.obj
avs.obj : error LNK2005: _Int64ShraMod32@12 already defined in 8bim.obj
avs.obj : error LNK2005: _Int64ShrlMod32@12 already defined in 8bim.obj
blob.obj : error LNK2005: _Int64ShllMod32@12 already defined in 8bim.obj
blob.obj : error LNK2005: _Int64ShraMod32@12 already defined in 8bim.obj
blob.obj : error LNK2005: _Int64ShrlMod32@12 already defined in 8bim.obj
bmp.obj : error LNK2005: _Int64ShllMod32@12 already defined in 8bim.obj
bmp.obj : error LNK2005: _Int64ShraMod32@12 already defined in 8bim.obj
bmp.obj : error LNK2005: _Int64ShrlMod32@12 already defined in 8bim.obj
cache.obj : error LNK2005: _Int64ShllMod32@12 already defined in 8bim.obj

there are total around 355 errors of these types..

Please help me..

Thanks in advance..

ADARSH KUMAR SINGLA
S.E.BIZ. INFOTECH. PVT. LTD.,
Chandigarh.

Re: LNK2005 Error.

Mike Dimmick2-Feb-04 2:36

Mike Dimmick

2-Feb-04 2:36

I think the errors are coming from around line 647 of WinNT.h, because the __inline keyword is being ignored. Perhaps your project has a macro called __inline?

Re: LNK2005 Error.

adarsh_sebiz10-Feb-04 1:46

adarsh_sebiz

10-Feb-04 1:46

Hi Mike..

Thankyou very much for replying me...

I find the line 647 in WinNT.h file and looked at the respective keyword
The code at line 647 is as follows:

__inline ULONGLONG
NTAPI
Int64ShllMod32 (
ULONGLONG Value,
DWORD ShiftCount
)
{
__asm {
mov ecx, ShiftCount
mov eax, dword ptr [Value]
mov edx, dword ptr [Value+4]
shld edx, eax, cl
shl eax, cl
}
}

__inline LONGLONG
NTAPI
Int64ShraMod32 (
LONGLONG Value,
DWORD ShiftCount
)
{
__asm {
mov ecx, ShiftCount
mov eax, dword ptr [Value]
mov edx, dword ptr [Value+4]
shrd eax, edx, cl
sar edx, cl
}
}

__inline ULONGLONG
NTAPI
Int64ShrlMod32 (
ULONGLONG Value,
DWORD ShiftCount
)
{
__asm {
mov ecx, ShiftCount
mov eax, dword ptr [Value]
mov edx, dword ptr [Value+4]
shrd eax, edx, cl
shr edx, cl
}
}

The solution suggested by you seems to be very beneficial to me..
but, i am not getting the solution suggested by you regarding __inline keyword in WinNT.h file,

So, Please suggest me solution in detail i.e. what i have to do to remove this error..

Thanks in advance.

ADARSH
S.E.Biz. Infotech Pvt. Ltd.,
Chandigarh.

argument and matrix

Dheeraj Mehta1-Feb-04 18:10

Dheeraj Mehta

1-Feb-04 18:10

can we send a two dimensional array as an argument????

set /clr option in MFC application?

scoct31-Jan-04 21:10

scoct

31-Jan-04 21:10

Can any experts in MFC application be kind and show me the way to setting the /clr options in MFC application type? There are too many restrictions and constraints (not compatible with /Gm, /ZI....etc) with this option on.

Currently cant seem to include "using <mscorlib.dll>" in MFC application. Any one care to tell me why and any solution? many thanx..

- -sC- -

reading inputs

Liyana30-Jan-04 12:13

Liyana

30-Jan-04 12:13

can someone tell me how do i read inputs from a text file?

(im still a beginner in C++,iv pored through a number of books but none has enlightened me..:sigh

the input is made of a hexadecimal number on each line, till the end of the file. the hex numbers represent an 8-bit number.

how do i convert the hex number to binary instead, upon reading it?

im aware that each character will be read in ASCII (correct me if im wrong)and stored into an array before the programmer can convert it to hex instead. but i dont know how the coding is like.

if im not mistaken, each input will be placed in a [1x8] array (or matrix). how do i change it into an [8x1] array instead, with the bit-0 placed as the first element of the new [8x1] array?can someone tell me the exact code please?

many thanx..

Re: reading inputs

Roger Wright3-Feb-04 4:25

Roger Wright

3-Feb-04 4:25

You're not getting much response to this, are you? Smile | :)

Okay, though I'm a beginner, too, I'll take a crack at it...

First, to read the file you can use fopen and streams, or CFile and a character buffer. Streams make me crazy, so I don't use them yet, but you may have better luck with them.

Converting the individual characters to integer values is easy. Use isdigit(ch) on each character read to find out whether it's in the range 0 to 9. If it is, use atoi(ch) to return the value as an integer. For characters A to F, I'd first check using isalpha(ch) to filter out carriage returns and such, then apply toupper(ch) to make them upper case, then a ~~Select~~ (oops) Switch statement to set the values (case 'A': value=10; case 'B':value=11; etc).

Combining two input characters into a one byte hex number is straighforward, I think. I'd try taking the first int value and shift it left (value<<4) by four bits, then add the second value to it. The lower byte of the int result should be the binary value you're looking for.

As for the rest - I don't understand the question well enough to guess. Could you clarify what you're trying to do with the array thingy?

As I said, I'm a beginner too, so any of the above may be entirely wrong. But that's the approach I'd start with, then let the many error messages that result lead me to a correct solution. Hopefully this is enough to get you started. Good luck! Big Grin | :-D

Heard in Bullhead City - "You haven't lost your girl -
you've just lost your turn..." [sigh] So true...

Re: reading inputs

Nik Vogiatzis18-Feb-04 17:22

Nik Vogiatzis

18-Feb-04 17:22

hmmm...

i won't give you the 'exact code' because this sounds like a homework question, but i will do this for you...

1. a [8x1] matrix is the transpose of a [1x8] matrix, hence they are identical (in the case of [qx1]/[1xq] matrices).

2. if you use a 'vector' type like a queue or a stack, then this will be your 'vector', else just create an array, i.e. char a[8];

3. assuming the number you are talking about is a character that represents a hex number like "^B" = 0x02h or "^J" = 0x08h, then what you will need to do is to bitwise 'AND' (which is a singular & not the AND operator which is &&) each bit position to find out whether the bit is set or not...
eg:

10010110 &<br />
     00000010<br />
     ========<br />
     00000010<br />

to do that calculation you would do something like
(var & 0x02)? 1:0;

i.e. if the result of the bitwise & is true return 1 else return 0.

so, you will need to bitwise AND it with

0x01   // 2^0 = 0000 0001
0x02   // 2^1 = 0000 0010
0x04   // 2^2 = 0000 0100
0x08   // 2^3 = 0000 1000
0x10   // 2^4 = 0001 0000
0x20   // 2^5 = 0010 0000

that should give you enough of the pattern for you to do the rest yourself...

4. finally, you can place the result of the bit in any order you want...

as for storing the ASCII character in an array first, this is highly unnecessary, you should be able to process each character as it comes through the stream...

try that, show me your results and if it looks like you need more help, we can try from there...

hope this 'enlightens' you a little more... the joy of programming is the 6 weeks of frustration followed by a fleeting 'ah' that signals the moment of complete enlightenment... it is the drug all programmers work towards... Smile | :)

cheers and good luck
nik

Nik Vogiatzis
PhD Candidate: University of South Australia
+++++++++++++++++++++++++++
Developing new generation Traffic Micro-simulation Tools for Traffic Engineers
em: nikolaos.vogiatzis@unisa.edu.au

C++ and Database

vin29-Jan-04 19:22

vin

29-Jan-04 19:22

Hi,

Is there any article available here which gives me an idea of connecting a c++ application to the database. I want to write a console database application. I don't want to use the MFC classes.

Can anyone help me, pls? Thanks in advance..

regards,

vini

Re: C++ and Database

Selvam R2-Feb-04 6:31

Selvam R

2-Feb-04 6:31

Hello,

try this,

http://www.codeproject.com/managedcpp/adodemo.asp

With Regards,
R.Selvam

Virtual destructor causes LNK2001 !!!

balkanese27-Jan-04 22:18

balkanese

27-Jan-04 22:18

Hi everybody!

I encountered the following problem:

I created a "class library (.NET)" project and made a first build, which produced a warning:

nochkclr.obj : warning LNK4099: PDB 'libc.pdb' was not found with 'C:\Programme\Microsoft Visual Studio .NET 2003\Vc7\lib\nochkclr.obj' or ...[/quote]

Ok, I ignored this warning and used the Wizard to generate a "Generic C++ class" with a virtual destructor. When I now try to rebuild my project I get two linker errors:

wiz.obj : error LNK2001: unresolved external symbol "void __cdecl operator delete(void *)" (??3@$$FYAXPAX@Z)

and

wiz.obj : error LNK2001: unresolved external symbol "void __stdcall `eh vector destructor iterator'(void *,unsigned int,int,void (__thiscall*)(void *))" (??_M@$$FYGXPAXIHP6EX0@Z@Z)

When I remove the "virtual" keyword in front of the destructor declaration both linker errors disappear!!! What the @&%$ is going on here?!?!

Thank you for your help,
Matej

swfsource: wanted code regarding creating buttons, please help!

adarsh_sebiz26-Jan-04 23:29

adarsh_sebiz

26-Jan-04 23:29

Hi everybody..

I have downloaded latest swfsource from www.sourceforge.com
It is a very good swfsource, which includes almost all the required features..

I gone through this swfsource, and became successfull in drawing simple shapes like rectangle, circle, triangle, curved-edged rectangle.....

I also tried drawing Gradients and buttons using this swfsource, but still not succeded..
Can anybody help me by sending the code(in swfsource) for drawing Gradients and Buttons?

thax in advance..

with regards,

ADARSH
Junior S/W Developer,
SEBIZ INFOTECH PVT. LTD.,
CHANDIGARH.

licensed control?

Roger Alsing26-Jan-04 22:56

Roger Alsing

26-Jan-04 22:56

how can i use a licensed control in managed vc++??

in c# when you add a licensed control to a form you get an embedded resource ("licenses.licx") file that tells vs.net to compile the license into the host app..

how does this work in vc++?

//Roger

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