Managed C++/CLI

Re: how to manage a multithread programm

26-May-05 16:03

By using objects like critical sections and mutexes to syncronise access to common objects between threads.

Christian Graus - Microsoft MVP - C++

ascap28-May-05 3:37

ascap

28-May-05 3:37

thanks for your reply. Smile | :)

Hi, i am from china.

Event Handle

Saksida Bojan25-May-05 20:38

Re: switching between panels

25-May-05 20:38

I have written __gc class. now i don't know how to make Event Hande, declare it and ovverride

Can you help me, please

switching between panels

richiemac24-May-05 23:16

richiemac

24-May-05 23:16

Hi all,

What's the best way for me to switch from one panel to the last visible panel. i.e. I have three panels on a form, panel2 (after some use) switches back to either panel1 or panel3 depending on which one was last being viewed. Does .net provide ant functions for this or will I have to write my own. If so what steps do I need to take.

Thanks
Rich

toxcct24-May-05 23:28

toxcct

24-May-05 23:28

what about Focus() ?

TOXCCT >>> GEII power
[toxcct][VisualCalc]

Toolbar icons not working

jain anant24-May-05 22:41

jain anant

24-May-05 22:41

Hi
I am working on a dialogbased application that contains a toolbar. I have been able to add more icons to toolbar but the problem is after clicking on new toolbar icons control does not reach their respective message handlers while the icons that were created initially are working fine.
Do anyone face any problem like this? Can anyone provide me a possible solution to this?

Regards,
Anant

A __gc problemo

Fernando A. Gomez F.24-May-05 13:32

Fernando A. Gomez F.

24-May-05 13:32

Hello there,

I'm doing a class library in C++.NET, and I declared two classes, A and b,
as follows:

public __gc class B;
public __gc class A : public baseA
{
private:
B *entrada;
B *salida;
};
public __gc class B : public baseB
{
private:
A **entrantes;
A **salientes;
};

However, while compiling I get the following error:

error C3160: 'entrantes' : cannot declare interior __gc pointer or reference
as a member of 'espacio_nombres::B'
error C3160: 'salientes' : cannot declare interior __gc pointer or reference
as a member of 'espacio_nombres::B'

Why this error happens? What can I do about it?

I mean, I already read the MSDN documentation on such error, but as far as I
understood, it says that a __gc class cannot have as member a pointer to
another __gc class. This sounds rather absurd to me, that's why I'm posting
this message. Hope someone can either confirm that what I understood was
right (and then I'll throw C++NET to the trash), or explain me the reason of
such error.

Thanks for any thought,
KK.

One day you'll find
that I have gone,
for tomorrow may rain, so
I'll follow the sun...

Re: A __gc problemo

ursus zeta28-May-05 7:44

ursus zeta

28-May-05 7:44

You can look this type of error up at the MSDN site:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vcmxspec/html/vcManagedExtensionsSpec_7_4.asp[^]
The solution is to make the class object (that you need a pointer to) a return type from a function.

How do I call a managed dll method from an unmanaged dll method?

leweyboy24-May-05 1:21

leweyboy

24-May-05 1:21

Here is the outline of the problem.

I have some third party software which can only access unmanaged dlls and
I need to pull some data out of an Access database and pass it into this software.

I have written a .net dll to get the data (using OleDb etc) which works great.

I have written a win32 dll that the third party software can access.

How do I get the win32 dll to call the method in the managed dll and pass the data into the app?

Can any one help with this?

Confused | :confused:

Re: How do I call a managed dll method from an unmanaged dll method?

Anonymous24-May-05 12:29

Anonymous

24-May-05 12:29

Wrap your managed functionality with a CCW

Re: How do I call a managed dll method from an unmanaged dll method?

geekisi7724-Jul-05 18:55

geekisi77

24-Jul-05 18:55

You've probably already solved the problem, but some excellent articles I would recommend on the subject are Michael Comb's article and this article by Harkos.

I'm doing a lot of work on this kind of stuff for fun. So long as you're programming in managed C++, you shouldn't need to create a second DLL, as Michael does in his article... (At least, I haven't found a way to directly export .NET functionality to an unmanaged app with C#, which is my favorite .NET language, but I do know how to get .NET C++ to speak almost directly to regular C++.)

Gustavo Keener
C++/C# Programmer

bools to bits

richiemac23-May-05 23:58

richiemac

23-May-05 23:58

Hi all,

I've got 8 boolean vars that I have to store. It will obviously be alot more efficient to store these 8 bools as a single byte but I don't know how to go about this task. Does VC++ provide any built in functionality for this or could anyone please tell me how to acheive this task.

Thanks in advance
Richie

Re: bools to bits

toxcct24-May-05 1:21

toxcct

24-May-05 1:21

easy

bool b0, b1, b2, b3, b4, b5, b6, b7;    <font color=green>// i consider here that b0 is the less significant bit

 
// initialization of your 8 booleans here...</font>
 
<font color=blue>char</font> c = b0 * 0x01 |
         b1 * 0x02 |
         b2 * 0x04 |
         b3 * 0x08 |
         b4 * 0x10 |
         b5 * 0x20 |
         b6 * 0x40 |
         b7 * 0x80;

as you know that to obtain the value of a byte with once bit set to 1, the remaining unset (set to 0), the mask formula is : bn * 2^n

---------------------------------------------------------
|  b7  |  b6  |  b5  |  b4  |  b3  |  b2  |  b1  |  b0  |
---------------------------------------------------------
  2^7    2^6    2^5    2^4    2^3    2^2    2^1    2^0
  0x80   0x40   0x20   0x10   0x08   0x04   0x02   0x01

(ps:this was not a managed C++ question to my sense because you can easily convert bools to booleans and chars to bytes)

TOXCCT >>> GEII power
[toxcct][VisualCalc]

Re: bools to bits

richiemac24-May-05 2:05

richiemac

24-May-05 2:05

Thanks,

I know it's not really a managed c++ question but I needed a quick answer and just posted. I promise I won't be so hasty in the future. Smile | :)

xml Problem

Saksida Bojan22-May-05 9:14

22-May-05 9:14

<?xml version="1.0" standalone="yes"?>
<CDList>
<CDList>
<cdid>11</cdid>
<Name>Halo - Combat Evolved</Name>
<Type>Igre</Type>
<Comment />
</CDList>
</CDList>

Code Snipset:

XmlDocument *xmlCDList = new XmlDocument;<br />
xmlCDList->Load(strCDListFileName);<br />
<br />
XmlElement *nodRoot = xmlCDList->DocumentElement;<br />
XmlNodeList *nodCDListCDID = nodRoot->GetElementsByTagName(S"CDID");

The problem is:
nodCDListCDID->Count is always 0 (zero)

Please help. Thanks in advance.

i think that i have crashed Will you forgave me, because i have crashed the forum

// I have already send email to webmasters

Christian Graus22-May-05 12:58

22-May-05 12:58

Saksida Bojan wrote:
because i have crashed the forum

Yes, it appears you have. And I was coming to follow up on another one of your questions, too....

Why use 'GetElementsByTagName' ? I think the 'tagname' is the ID element. Try nodRoot->SelectNodes, with this: "/CDList/CDList/cdid", or this: "//cdid". These are valid xpaths. Why does the CDList node nest a copy of itself ?

Also, XML is case sensitive, if the above code was to work, you'd nee to make "CDID" the same case as in the XML.

Christian Graus - Microsoft MVP - C++

Saksida Bojan22-May-05 20:38

22-May-05 20:38

Thanks. That helped. But i have still a question.

Why does this one worke. Oh yeah i Have change from cdid to CDID

XmlNodeList *nodCDListName = nodRoot->GetElementsByTagName(S"Name");

PS: First CDList is database, Second CDList is table.

Christian Graus23-May-05 1:18

23-May-05 1:18

Saksida Bojan wrote:
Why does this one

Why wouldn't it ? It's correct case.

Saksida Bojan wrote:
First CDList is database, Second CDList is table.

Well, isn't that a little silly ?

Christian Graus - Microsoft MVP - C++

Saksida Bojan24-May-05 20:07

24-May-05 20:07

Now i got werious problems. and i will backtrack. but can you tell me where can i find a good Xml Guide or tutorial.

Christian Graus25-May-05 12:42

25-May-05 12:42

I bought SAMS XML Unleashed, it was a good book. MSPress have a good XML book as well.

Christian Graus - Microsoft MVP - C++

Saksida Bojan25-May-05 20:36

25-May-05 20:36

Thanks for the help. I have found an XML guide on the web

http://www.functionx.com/

xml Problem

Saksida Bojan22-May-05 9:05

22-May-05 9:05

The xml File:

<cdlist>
<cdlist>
<cdid>11
<name>Halo - Combat Evolved
<type>Igre
<comment>

Code snipset:

XmlDocument *xmlCDList = new XmlDocument;<br />
xmlCDList->Load(strCDListFileName);<br />
XmlElement *nodRoot = xmlCDList->DocumentElement;<br />
<br />
XmlNodeList *nodCDListCDID = nodRoot->GetElementsByTagName(S"CDID");

Now the problem is:
nodCDListCDID->Count is always 0 (zero)

Can anybody help. And thanks in the advance