C / C++ / MFC Discussion Boards

Code-o-mat21-Nov-08 0:06

21-Nov-08 0:06

1. As far as i know there's no standard way to do that.
2. What do you mean? If you want the address of the Mem variable, then use &, so &Mem. If you store a memory location in Mem, then use a pointer type, like int *Mem, but if you want to convert int to a pointer, then you can use for example (void *)Mem.
3. You can declare const "variables" to which you specify a value and then it cannot be modified anymore. For example const int m_Constant;, you would give a value to this in the contstructor of yor class. If you want to modify a variable "inside" the containing class but not outside then declare it as protected or private amd supply either a Get method for it or a const reference to it. so if you have int m_variable; then you can do either const int &GetVariable() { return m_variable; } or you can do const int &m_constVariable; and initialize this in the constructor using m_variable.

Re: Easy questions about C++

akirilov21-Nov-08 0:22

akirilov

21-Nov-08 0:22

2. With some code will be easier to explain:

int Mem;
...
Mem = LocalAlloc(LHND, ...);
...
WriteFile(f, (void *) Mem,...)

I receive exception during runtime, so my question is what expression to use so it will work properly (writes the pointed by Mem block to file)

Re: Easy questions about C++ [modified]

Code-o-mat21-Nov-08 0:29

Code-o-mat

21-Nov-08 0:29

Ok, new edit, i misread you there the first time. LocalAlloc gives you a handle to a memory location, not the memory location itself. Declare your variable as HANDLE, not int, since LocalALloc, unless specified differently, will give you a HANDLE. You have to use LocalLock and LocalUnlock to actually access the memory. But may i ask why you need to use LocalAlloc instead of new or malloc? So basicly, if you have to use LocalAlloc you have to LocalLock(handle), this will give you a void * pointer that points at the memory you allocated, you can feed this to WriteFile (didn't go into WriteFile itself so i assume you know what you are doing with that) and then use LocalUnlock to unlock the memory, also use LocalFree to free it.

modified on Friday, November 21, 2008 6:36 AM

Re: Easy questions about C++

akirilov21-Nov-08 4:17

akirilov

21-Nov-08 4:17

LocalAlloc gives you a handle to a memory location, not the memory location itself
Actually, that depends on the first parameter.
In my case (for Windows Mobile) it always return the actual address, so it is OK.

Re: Easy questions about C++

Code-o-mat21-Nov-08 6:23

Code-o-mat

21-Nov-08 6:23

As i said, "unless specified differently". So if you get a pointer at the memory location why do you store it in an int?

Re: Easy questions about C++

bulg21-Nov-08 12:59

bulg

21-Nov-08 12:59

I agree. But if you insist, then you should just 'cast' it as a pointer when you Write -

<br />
WriteFile(...<br />
(long*)Mem, // mem is an address<br />
...<br />

Confusions related to Dll.

Nilesh Hamane20-Nov-08 23:34

Nilesh Hamane

20-Nov-08 23:34

Can anyone tell me what is the main purpose of Dll? As we can get the data from Dll, can we put the data in Dll? I am not talking about code, talking about single Dll. If you know about Dll then please share your knowledge..

http://nnhamane.googlepages.com/

Re: Confusions related to Dll.

SandipG 20-Nov-08 23:50

SandipG

20-Nov-08 23:50

May be this[^] and this[^] help.

Regards,
Sandip.

Re: Confusions related to Dll.

tasumisra21-Nov-08 1:14

tasumisra

21-Nov-08 1:14

Dll is nothing but a reusable code.. its a dead thing it need to invoke from some where ..
by it self DLL cant do anything.

dll can be in any language that supports Pointer Functionality.

Dll is used to process the data

Dll is used to apply Business logic

Dll can be called from any place.

can you please specify what exactly you are looking here in some specific manner???

vikas da

Re: Confusions related to Dll.

22491721-Nov-08 15:41

224917

21-Nov-08 15:41

Nilesh Hamane wrote:
Can anyone tell me what is the main purpose of Dll?

Consider you know some function that can be helpful to other programmers and, they are ready to pay you for it, so how would you prefer to give it? you can give your source code, os a better option would be to compile your code as a dll and then sell, because the dll after compilation gets converted to machine code.

Nilesh Hamane wrote:
As we can get the data from Dll, can we put the data in Dll?

This is not the purpose of dlls, you should use files or databases for storing your application data.

-Suhredayan

Delete Shortcut file

MsmVc20-Nov-08 22:11

MsmVc

20-Nov-08 22:11

Hile All

How can i delete shortcut file form desktop?Plz help me

Re: Delete Shortcut file

Chandrasekharan P20-Nov-08 22:19

Chandrasekharan P

20-Nov-08 22:19

what is the problem in that? select the file and use shift+ delete button

Re: Delete Shortcut file

MsmVc20-Nov-08 22:29

MsmVc

20-Nov-08 22:29

Thanks for reply dude..

I want to delete through code.

Re: Delete Shortcut file

Iain Clarke, Warrior Programmer20-Nov-08 22:39

Iain Clarke, Warrior Programmer

20-Nov-08 22:39

Can you not delete it the same way you'd delete any other file? (DeleteFile)

If you're struggling to find the desktop, you can use SHGetFolderPath with CSIDL_DESKTOPDIRECTORY.

Iain.

Re: Delete Shortcut file

MsmVc20-Nov-08 22:53

MsmVc

20-Nov-08 22:53

i am not struggling to find desktop path,problem is delete shortcut file.So plz give me tips to do that.
Thanks for reply

Re: Delete Shortcut file

Iain Clarke, Warrior Programmer20-Nov-08 23:03

Iain Clarke, Warrior Programmer

20-Nov-08 23:03

Read the first bit of my post. I repeat: "What is wrong with DeleteFile" ?

CString s = szPathDesktop;
s += _T("\\myshortcut.lnk");
if (!DeleteFile (s))
{
    dw = GetLastError ();
}

Iain.

Colored cursor became Black cursor in Vista

Rahul Vaishnav20-Nov-08 22:00

Rahul Vaishnav

20-Nov-08 22:00

Hi all,

I am facing one problem with my application.
I am using "hnwse.cur" by adding it into resource

code is like

HCURSOR hDragCur = (HCURSOR)LoadImage(_AtlBaseModule.m_hInst, (LPCWSTR)MAKEINTRESOURCE(IDC_HAND_CURSOR),IMAGE_CURSOR,  28, 28, LR_DEFAULTCOLOR);
if(hDragCur)
  SetCursor(hDragCur);

This is working fine in Xp but in vista it is showing black hand cursor.

Can any buddy please help me to resolve this problem.

Confused | :confused:

Dynamic Edit Boxes

Chandrasekharan P20-Nov-08 21:30

Chandrasekharan P

20-Nov-08 21:30

I wnat to know how can i create a series of edit boxes dynamically.
for exampe in a dialog box there is an edit box and a button. i type in 5 in the edit box and enter the button,

once i click on the button 5 edit box should be created dynamically.. is it possible to do it?

Re: Dynamic Edit Boxes

Cedric Moonen20-Nov-08 21:41

Cedric Moonen

20-Nov-08 21:41

Yes, take a look at CEdit::Create[^] (BTW, all windows can be created this way).

Cédric Moonen
Software developer

Charting control [v1.5]
OpenGL game tutorial in C++

Re: Dynamic Edit Boxes

Chandrasekharan P20-Nov-08 23:11

Chandrasekharan P

20-Nov-08 23:11

Mission Accomplished
Thanks

which dll to operate with DNS Service?

Ponzano Paolo20-Nov-08 21:30

Ponzano Paolo

20-Nov-08 21:30

Hello,
I need to work with DNS primary lookup zone, rigth now I'm doing it by calling shell, anyone knows which dll should I use to add/remove records?

Thanks in advance
Paolo

Re: which dll to operate with DNS Service?

Randor 20-Nov-08 22:34

Randor

20-Nov-08 22:34

You can use the IP Helper API[^] to add/remove DNS lookup zones. I believe there are some samples of its usage here on codeproject.

Best Wishes,
-David Delaune

Comparing two GUIDs

tasumisra20-Nov-08 20:26

tasumisra

20-Nov-08 20:26