C / C++ / MFC

8-Jun-07 0:08

Hi, everyone!
I meet a strange problem. The application I'm developing has a parent window and a popup dialog. I wrote a class encapsulate a SOCKET and declare a varriable of it in the parent window. When some data were received, a message will be sent to parent window. Then when the dialog is popupped, I use a pointer of the class and let it point to the varriable in the parent class. After that, I assign the dialog's HWND to the class. So the message will be sent to the dialog as I think. But the fact is the class can't work when the dialog displayed at all! I think declareing a new varriable will cost too many CPU's time because the class generate a new thread. So I hope someone could be kind to tell me how to resolve this problem without declare a new varriable. Thanks! Smile | :)

Jijo.Raj8-Jun-07 2:47

Jijo.Raj

8-Jun-07 2:47

Hi Pal,

Seems very difficult to understand the problem you are facing... please describe more clearly.

Regards,
Jijo.

________________________________

Yesterday is history,
Tomorrow is a mystery,
But today is a present.

whiteclouds10-Jun-07 14:39

10-Jun-07 14:39

The essential of my problem is that what time is approprate to assign a handle of a dialog to a varriable. In InitDialog() or in WM_CREATE processing function? If the time is wrong, the message can't be received.

Mark Salsbery8-Jun-07 7:09

Mark Salsbery

8-Jun-07 7:09

whiteclouds wrote:
When some data were received, a message will be sent to parent window

By who?

whiteclouds wrote:
But the fact is the class can't work when the dialog displayed at all!

Is this a modal dialog?

whiteclouds wrote:
I think declareing a new varriable will cost too many CPU's time because the class generate a new thread.

??? Who/what/where/why is another thread being created?

Mark

"Posting a VB.NET question in the C++ forum will end in tears." Chris Maunder

whiteclouds10-Jun-07 14:40

Another question on c++ template

10-Jun-07 14:40

Maybe I can resolve this problem by other way. If I success, I'll tell everyone answered.

Yuwen Zhou8-Jun-07 0:06

8-Jun-07 0:06

Hi guys, I have the second question about template. I encountered it during my studying.

for example, I have a template class both in .h & .cpp files as follow:

1:  // a.h
2:  template < class T >
3:  class TTEST
4:  {
5:  public:
6:    struct TS
7:    {
8:      int i ;
9:    } ;
10: public:
11:   TS* test1() ;
12:  } ;

13: // a.cpp
14: #include "a.h"
15: template < class T >
16: TS* TTEST < T >::test1()
17: {
18:   return NULL;
19: }

But I got a compiler error at line 16 while building it. I know there is something wrong with the " TS* ", but I don't know how to fix it. Could an y one help me ? thx !

CPallini8-Jun-07 0:26

8-Jun-07 0:26

Try to replace the function definition (.cpp file) with:

template < class T > 
TTEST < T >::TS * TTEST < T >::test1()
 {
   return NULL;
 }

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

Yuwen Zhou8-Jun-07 0:30

8-Jun-07 0:30

Hi, CPallini. I have tried this way before, and failed with a similar error, in vc.

CPallini8-Jun-07 0:36

8-Jun-07 0:36

Strange, it works fine on my system (VS6).
Are you sure the sintax was the same?

Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

David Crow8-Jun-07 2:59

David Crow

8-Jun-07 2:59

Yuwen Zhou wrote:
I have tried this way before, and failed with a similar error, in vc.

Then you must've made a type-o. Simply qualifying TS is all that's needed.

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Christian Graus8-Jun-07 0:27

Christian Graus

8-Jun-07 0:27

I think it has nothing to do with templates. I thnk in the CPP file you need to put TTEST::TS *, because the struct is defined inside the class.

Christian Graus - Microsoft MVP - C++
Metal Musings - Rex and my new metal blog
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )

whiteclouds8-Jun-07 0:30

8-Jun-07 0:30

I think u should modify the code as following:

<br />
1:  // a.h<br />
2:  struct TS<br />
3:  {<br />
4:    int i ;<br />
5:  } ;<br />
6:  template < class T ><br />
7:  class TTEST<br />
8:  {<br />
9:  public:<br />
10:   TS t;<br />
11: public:<br />
12:   TS* test1() ;<br />
13:  } ;<br />
14: // a.cpp<br />
15: #include "a.h"<br />
16: template < class T ><br />
17: TS* TTEST < T >::test1()<br />
18: {<br />
19:   return NULL;<br />
20: }<br />

Yuwen Zhou8-Jun-07 0:37

8-Jun-07 0:37

thanks for focusing ! I agree with you that it will work in your way, but to put TS's definition inside class TTEST will be more preferable.

Matthew Faithfull8-Jun-07 0:36

Matthew Faithfull

8-Jun-07 0:36

Remeber you cannot implement a templated class's member functions in a separate .cpp file. You have to put the implementation in the .h file along with the class definition. Try moving all your original TTEST code into the .h file and see if it compiles them.
This is a limitation of C++ compilers which I can't at the moment remember the excuse for. You may need to ask Mr Stroustrup Smile | :)

Nothing is exactly what it seems but everything with seems can be unpicked.

Yuwen Zhou8-Jun-07 0:49

8-Jun-07 0:49

haha, thx for focusing, Matthew ! I am afraid Mr Stroustrup will be too busy to reply me. I know the way to separate a template into .h & cpp files. You could search it inside codeproject(I couldn't remember the exact link).

CPallini8-Jun-07 2:09

8-Jun-07 2:09

Probably Mr.Stroustrup don't know that C++ Compiler is so smart to generate function using only declarations
Big Grin | :-D

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

Yuwen Zhou8-Jun-07 5:10

8-Jun-07 5:10

Hi all, after my searching around the web, I have found solution of my problem. Correct codes are shown bellow:

<br />
1:  // a.h<br />
2:  template < class T ><br />
3:  class TTEST<br />
4:  {<br />
5:  public:<br />
6:    struct TS<br />
7:    {<br />
8:      int i ;<br />
9:    } ;<br />
10: public:<br />
11:   TS* test1() ;<br />
12:  } ;<br />
13: // a.cpp<br />
14: #include "a.h"<br />
15: template < class T ><br />
16: typename TTEST < T >::TS* TTEST < T >::test1()<br />
17: {<br />
18:   return NULL;<br />
19: }<br />

pls notice line 16, a function "typename"(it is considered as a function in MSDN) was added between the "template < >" and the function return type, since the compiler can only recognise TTEST < T >::TS as a data type in this way. On the other hand, I could use class TTEST in my caller function just by simply include the a.cpp file instead of a.h in my own source file.

auto_ptr

vibindia7-Jun-07 23:42

vibindia

7-Jun-07 23:42

Hi
#include<memory.h>
#include<iostream.h>
class CStack
{
public:
void push()
{
cout<<"push";
}
};

int main()
{
auto_ptr<CStack> pt( new CStack );
return 0;
}

For this code I'm getting error

: error C2065: 'auto_ptr' : undeclared identifier

what header file should i include for auto_ptr.

VIBIN

"Fool's run away,where angle's fear to tread"

Re: auto_ptr

CPallini7-Jun-07 23:52

7-Jun-07 23:52

try

#include <memory>

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

Re: auto_ptr

vibindia8-Jun-07 0:00

vibindia

8-Jun-07 0:00

Ya i have included that header file.But i am getting error:

E:\C++\ClassPointer\ClassPointer.cpp(14) : error C2065: 'auto_ptr' : undeclared identifier Sniff | :^)

=================================================
E:\C++\ClassPointer\ClassPointer.cpp(14) : error C2275: 'CStack' : illegal use of this type as an expression
E:\C++\ClassPointer\ClassPointer.cpp(4) : see declaration of 'CStack'
E:\C++\ClassPointer\ClassPointer.cpp(14) : error C2065: 'pt' : undeclared identifier

VIBIN

"Fool's run away,where angle's fear to tread"

Re: auto_ptr

CPallini8-Jun-07 0:05