C / C++ / MFC Discussion Boards

Yaron12631-Mar-04 8:45

31-Mar-04 8:45

Hi,
I was wondering if it was possible to change only one member function in a template specifialization
and have the rest the same without having to duplicate the code in the specifialized class?

Thanks.

Re: Template Specialization

antlers31-Mar-04 10:51

antlers

31-Mar-04 10:51

Yes--

Just define the specialization of the function in the header file after the template definition.

Like this:

<br />
template <typename foo> class bar {<br />
public :<br />
int func1() { ... }<br />
int func2() { ... }<br />
...<br />
}<br />
<br />
// Specialization of func2 in bar for class q<br />
template<> bar<q>::func2()<br />
{<br />
...<br />
}<br />

iterate through vector

wadstar31-Mar-04 8:16

wadstar

31-Mar-04 8:16

hi me again, ive been writting code that fills a vector with random numbers from two sources, all even elements are filled from source1 and odd ones from source2...this now works fine after much debuggingmyhead.

ive been trying to to do next part of my function which is more complex, it basically uses a iterator with a const value of 0.002. which is 20millseconds.

this iterator goes to every single element in the array and goes through every element in 0.002 segments..i.e if element value is 3.6 then it goes through it in 1,800 segements. basically splitting up the element into segments,

and it does this to distingusih between numbers from sourceone and sourcetwo because these numbers are usesd elsewhere.. i will paste the code which fills the vector and ive COMMENTEDout the 'new' but it doesnt work imnot sure what else to do.

#include <iostream><br />
#include <vector><br />
#include <stdlib><br />
#include <time><br />
#include <numeric><br />
#include <algorithm><br />
#include "exponentialgenerator.h"<br />
<br />
using namespace std;<br />
<br />
ExponentialGenerator one = 1.41;<br />
ExponentialGenerator two = 1.71;<br />
<br />
double nextNumber = reinterpret_cast<double>(one.generate());<br />
<br />
double nextNumber2 = reinterpret_cast<double>(two.generate());<br />
<br />
int counter = 0;<br />
<br />
void fillVectorToSum(vector<double>& v, double sum)<br />
{<br />
<br />
    int total = 0;<br />
    do {<br />
		if (counter++ % 2){<br />
			v.push_back(nextNumber);<br />
			total += nextNumber;<br />
			nextNumber = one.generate();<br />
			}<br />
		else {<br />
			v.push_back(nextNumber2);<br />
			total += nextNumber2;<br />
			nextNumber2 = two.generate();<br />
			}<br />
<br />
    } while(total+nextNumber+nextNumber2 <= sum);<br />
    if(total < sum)<br />
        v.push_back(sum-total);<br />
}<br />
<br />
/**void goThroughVector(vector<double>& doubleVector, const vector<double>::iterator imMutableIt, double currentElement)<br />
{<br />
	*imMutableIt = 0.002;<br />
<br />
	doubleVector.push_back(1.0); <br />
	doubleVector.push_back(2.0);<br />
<br />
	imMutableIt it = doubleVector.begin();<br />
	<br />
<br />
     double currentElement; <br />
	<br />
		 while (*imMutableIt = 0.002;){<br />
			 if (currentElement = nextNumber)<br />
				return currentElement;<br />
			 else (currentElement = nextNumber2)<br />
				return (currentElement*10);<br />
		 }<br />
	imMutableIt endIt = doubleVector.end();<br />
<br />
<br />
}**/<br />
int main()<br />
{<br />
<br />
    srand((unsigned) time(NULL));<br />
    vector<double> v;<br />
    fillVectorToSum(v, 30);<br />
<br />
    cout << "Number of elements: " << v.size() << "\nTotal: "<br />
         << accumulate(v.begin(), v.end(), 0) << endl;<br />
    copy(v.begin(), v.end(), ostream_iterator<double> (cout,"  "));<br />
	<br />
	<br />
<br />
<br />
<br />
<br />
}

Member of domain

orcun colak31-Mar-04 5:57

orcun colak

31-Mar-04 5:57

I would like to determine if a computer is a member of domain or not.
I tried GetPDC but it seem to be returning the workgroup's name.
Enumerating network is also useless, since it is returning other standalone machine's names.
Any ideas about how to do this?

Orcun Colak

Re: Member of domain

David Crow31-Mar-04 8:03

David Crow

31-Mar-04 8:03

Use NetWkstaGetInfo().

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Re: Member of domain

Robert M Greene31-Mar-04 15:55

Robert M Greene

31-Mar-04 15:55

Try
NetWkstaGetInfo

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/netmgmt/netmgmt/netwkstagetinfo.asp[^]

and NetUserGetInfo

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/netmgmt/netmgmt/netusergetinfo.asp[^]

.............................
There's nothing like the sound of incoming rifle and mortar rounds to cure the blues. No matter how down you are, you take an active and immediate interest in life.

TextOut()

ns31-Mar-04 4:49

31-Mar-04 4:49

In my view class in the LButtonDown()I have

CPaintDC dc;
CRect c;
GetClientRect(&c);

dc.TextOut(c.Width()/2, c.Height()/2," abc");

I dont see the text when I click.

DO I need a different kind of DC? I was actually trying to do DrawIcon but when i didnt see the icon, I thought I'd see if textout worked....neither does..
thanks,
ns

Re: TextOut()

Prakash Nadar31-Mar-04 4:54

Prakash Nadar

31-Mar-04 4:54

Try CClientDC instead of CPaintDC.

MSN Messenger.
prakashnadar@msn.com

Tip of the day of visual C++ IDE.
"We use it before you do! Visual C++ was developed using Visual C++"

Re: TextOut()

ns31-Mar-04 7:03

31-Mar-04 7:03

Thanks! The textout works. But this doesnt still:

dc.DrawIcon( f, w, hIcon3);

Does this need yet some other special DC? Why wasnt PaintDC suitable for TextOut? How do you choose which type of DC to use?
Thanks again,
ns

Re: TextOut()

grigsoft31-Mar-04 8:29

grigsoft

31-Mar-04 8:29

Imho drawing in mouse message handler is not a good practice. Does your picture should stay after you release button? Try placing other application above yours, and your picture will be lost.

Igor Green
http://www.grigsoft.com/ - files and folders comparison tools

Re: TextOut()

monrobot1331-Mar-04 8:39

monrobot13

31-Mar-04 8:39

ns wrote:
Why wasnt PaintDC suitable for TextOut

It wasn't that the CPaintDC wasn't suitable for a TextOut call it's that it wasn't suitable for where you were using it. CPaintDC should only be used in an OnPaint message handler. The reason behind this, as far as I know, is that it calls some functions (BeginPaint, EndPaint) that set the update region (area you can actually "paint" in) and in your button handler there probably hasn't been any part of your window that's been invalidated, therefore a CPaintDC wouldn't have any valid drawing area.

- Aaron

Re: TextOut()

GflPower31-Mar-04 13:27

GflPower

31-Mar-04 13:27

在这个论坛上必须发英文吗
I'm sorry!

I can't speak english

CDC* dc;

dc = GetDC();

dc->textout();

d

Finding a structures address

Xen3h31-Mar-04 4:27

Xen3h

31-Mar-04 4:27

I use some structures in an app using pointers, basically everytime the program gets updated these addresses change slightly, I usually get told by someone what the address is.

Basically I want to be able to automatically find the address of the structure in the app, but i'm not sure how to do it.. I think i remember someone saying pattern searching or something.

Any help is appreciated. Smile | :)

Re: Finding a structures address

David Crow31-Mar-04 8:06

David Crow

31-Mar-04 8:06

I think I know what you are asking, but your comments make me think otherwise. Have you tried the address-of operator?

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Re: Finding a structures address

Prakash Nadar31-Mar-04 14:44

Prakash Nadar

31-Mar-04 14:44

What do you use the address for ? is it a memeory address or a file offset number ?

MSN Messenger.
prakashnadar@msn.com

Tip of the day of visual C++ IDE.
"We use it before you do! Visual C++ was developed using Visual C++"

Re: Finding a structures address

gUrM33T31-Mar-04 16:47

gUrM33T

31-Mar-04 16:47

Your question is not clear.

Gurmeet S. Kochar

If you believe in God, it's because of the Devil

Re: Finding a structures address

John R. Shaw31-Mar-04 21:56

John R. Shaw

31-Mar-04 21:56

This question makes no since! What do you mean by "...someone what the address is." Either the code knows what the address is or it doesn't. You might know what the address is at a given run of the program and your debugger might give you the same address every time you rebuild, until you modify the code. But the address may be relitive to the base address of your program or it may be allocated (could be anywhere). You should never need to know the actual address (except maybe when debugging). Pattern searching has nothing to do with finding an address.

/* in C */
struct whatever {...};
struct whatever* pAddr; /* uninitialized pointer/address */
or
myfunct(struct whatever* pAddr)
{
    /* modify stucture whatever */
}

// in C++
struct whaterver {...};
whatever* pAddr; /* uninitialized pointer/address */
or
myfunct(whatever* pAddr)
{
    /* modify stucture whatever */
}

INTP

how to draw the background bmp for the statusbar?

benben31-Mar-04 3:52

benben

31-Mar-04 3:52

Hi:
I want to let the CStatusBar support background bmp(just like CRebar's background).I try to draw the bmp in the onerasebackground() function,but it seems that this way only works in winxp;in win98/me/2000,the background doesn't show correctly.Could you give me any idea or any examplt?

Thanks
Benben

Re: how to draw the background bmp for the statusbar?

Alexander ^M.,1-Apr-04 3:44

Alexander ^M.,

1-Apr-04 3:44

try OnPaint

Don't try it, just do it! Wink | ;-)

Thank you very much!

benben1-Apr-04 17:23

benben

1-Apr-04 17:23

Thanks
Benben

Windows Service vs. Sockets

RickyC31-Mar-04 3:42

RickyC

31-Mar-04 3:42

Hy everybody!
I'm having a little problem in a Windows Service (DOS App)...
I create a CAsyncSocket derived class to work as a server. I use the Listen(), and after that, I wait for a connection on my OnAccept(). Everything works fine... the socket is created, is listening (so I hope)... but when a connection request comes, nothing happens... and don't run the OnAccept mapped function. Frown | :(

(where I'll make Accept() in another socket)
The Unix process (my client) says to me that is connected and begin send data to me... but I even know that I'm connected with it. Confused | :confused:

Does anybody knows what could be happen?

thanks folks,
cheers!

Message Pump Missing?

Xiangyang Liu 刘向阳31-Mar-04 4:41

Xiangyang Liu 刘向阳

31-Mar-04 4:41

Here is a possible cause of your problem:

The OnAccept() method is not called because there is no message pump in your windows service.

Here is my understanding (see MFC source code): When a request comes from a remote program, it is turned into a windows WM_SOCKET_NOTIFY message and posted to an internal window used by CAsynSocket. When the WM_SOCKET_NOTIFY message is processed by MFC, it will invoke the event handlers such as OnAccept, OnReceive, etc. Unless you added a message loop to your windows service, the WM_SOCKET_NOTIFY message will never be processed.

If you cut and paste your code into a MFC dialog based application, assuming there is no other bug, it will work.

If that is confirmed to be the problem, there are at least two relatively easy solutions.

1. Start a separate thread from the windows service. Create the socket in this new thread, call Create/Bind/Listen for the socket, then use a loop to call Accept/Reciev/Send (i.e. don't rely on the OnAccept notification).

2. Move everything to a dialog based application, when the program works, use this special windows service[^] to run your application.

Good luck.

P.S. Solution 1 does not work if multiple clients have to connect to your server simultaneously, in which case you need to add a message pump and rely on the socket events.

My articles and software tools

Re: Message Pump Missing?

RickyC31-Mar-04 5:59

RickyC

31-Mar-04 5:59

Ok, thanks Xiangyang Liu
I'll see if this is the problem, and if so, I'll try one of your sugestions.
Thanks a lot! Smile | :)

cheers!

Re: Windows Service vs. Sockets

Robert M Greene31-Mar-04 16:00

Robert M Greene

31-Mar-04 16:00

The MFC socket classes depend on a message loop to process the notifications properly. Services don't have message loops (normally anyways) so I always use the low level socket routines for services. Check MSDN and they will explain the limitations of CSocket amd CAsyncSocket.

.............................
There's nothing like the sound of incoming rifle and mortar rounds to cure the blues. No matter how down you are, you take an active and immediate interest in life.

Re: What is "Visual Studio (MSI)"?

Vasiliy Baranov31-Mar-04 3:36

Vasiliy Baranov

31-Mar-04 3:36

Well, Microsoft Installer (MSI) is a technology (or file format) rather than a tool for authoring installations. InstalShield and Wise produce MSI installations too.

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.