C / C++ / MFC Discussion Boards

Re: Internet explorer functions

David Crow23-Apr-03 3:00

David Crow

23-Apr-03 3:00

It depends on the OS. With NT, 2000, and XP, you can restrict what drives, and folders, the current user has access to.

GDI programming question

pankajdaga22-Apr-03 23:45

pankajdaga

22-Apr-03 23:45

Hi everyone,

I have a question about XOR painting. I have a window with a bitmap background. Whenever I drag my mouse in the window, I want to highlight the selected area using XOR mode. Of course, I could do that by

::InvertRect(RECT & rect)

However, now I have some other areas that I want to highlight..but with a different color and I still want the background pattern to show under the highlighted rectangle. Is it possible to do an XOR drawing with some bit switched off or something like that. I want the XOR effect, but a different shade.

I hope my problem is clear enough. If anyone has any ides or suggestions, I would really appreciate it.

Thanks,
Pankaj

Without struggle, there is no progress

Re: GDI programming question

zeki yugnak23-Apr-03 3:02

zeki yugnak

23-Apr-03 3:02

hi..

I thing that this function use logical NOT operation!!!

problem getting widht/height of formview

sandrineV22-Apr-03 23:24

sandrineV

22-Apr-03 23:24

Hello,

I have problems retrieving the height and width of a formview :
When I call the OnPaint() function, I want to display a picture at a specific position in a formview so I need to know its current size.

What I do to get the size is, in the OnPaint() function :

CRect rect;
this->GetWindowRect(&rect);
int winwidth=rect.Width();
int winheight=rect.Height();

But I get a width and height of zero.

Does anyone know what I did wrong ?

Thanks for your help,

Re: problem getting widht/height of formview

Cedric Moonen22-Apr-03 23:31

Cedric Moonen

22-Apr-03 23:31

Try this instead:

CRect ClientRect;
GetClientRect(ClientRect);

This will retrieve the width and the heigth of the client area (so what you need Smile | :)

) !

Re: problem getting widht/height of formview

sandrineV23-Apr-03 2:55

sandrineV

23-Apr-03 2:55

Thanks for your help, but it doesn't work either : I still have a width and height of zero with :

CRect rect=new CRect();
GetClientRect(&rect);

int winwidth=rect.Width();
int winheight=rect.Height();

Re: problem getting widht/height of formview

basementman24-Apr-03 7:32

basementman

24-Apr-03 7:32

Have you tried the GetTotalSize() method of the FormView (scrollview implemented)?

string value in watch window

Hugo Hallman22-Apr-03 22:47

Hugo Hallman

22-Apr-03 22:47

I have a structure like
struct Id {
LPCSTR sId; /* note that this is the first member */
unsigned nId;
};

I'd LOVE to have vc-debugger to display the sId value (in place of {...}) in the watch/this/locals/auto window, like CString does.

I've looked through the sources for CString and haven't quite figured it out.

Deriving from string isn't an option.

Any suggestions?

Re: string value in watch window

Martyn Pearson23-Apr-03 1:00

Martyn Pearson

23-Apr-03 1:00

Locate the file autoexp.dat - mine (Visual Studio 6) is in the MSDev98\bin directory.

This file contains details of the expansions used when debugging. Open this up, and there is a huge bit at the top telling you how to do your own stuff. Further down you can see the entry for CString.

Hope this helps!

Re: string value in watch window

David Crow23-Apr-03 3:15

David Crow

23-Apr-03 3:15

Are you saying that when you view Id.sId in the watch window, it shows ellipses instead of the actual data? If you do not know about the autoexp.dat file, and thus have never altered it, then I'm unclear on your question. By default, the contents of the address pointed to by Id.sId are displayed. If you had just Id in the watch window, it would indeed show up as {...}.

Re: string value in watch window

Hugo Hallman27-Apr-03 9:23

Hugo Hallman

27-Apr-03 9:23

thanks a lot. I didn't know of autoexp.dat, but have always suspected something like it. Thank you very much for telling me of it.

(Thought it was built into vstudio. -darn M$)

How do I put an icon on Single Document screen..

IrishSonic22-Apr-03 22:38

IrishSonic

22-Apr-03 22:38

How do I put an icon on a Single Document screen and then be able to click on the icon to call my dialog??

Thanks,
grahamoj.

Re: How do I put an icon on Single Document screen..

David Crow23-Apr-03 3:03

David Crow

23-Apr-03 3:03

Where do you want the icon? Are you sure you're not talking about a toolbar button?

Memory check error

Cedric Moonen22-Apr-03 22:25

Cedric Moonen

22-Apr-03 22:25

Hello,

I have a structure that looks like:

struct STRUCT_EXAMPLE<br />
{<br />
     int Data1;<br />
     int Data2;<br />
     float Data3;<br />
     ...<br />
<br />
     void Clear() { memset(this,0,sizeof(STRUCT_EXAMPLE)); }<br />
};

Now, I allocate an "array" of this structure:

STRUCT_EXAMPLE* pPtr = new STRUCT_EXAMPLE[NewValue];<br />
for (int i=0;i<NewValue;i++)<br />
   pPtr[i].Clear();

Everything works fine but when I delete the array:

if (pPtr)<br />
delete[] pPtr;

I have a memory check error:
memory check error at 0x0145C630 = 0x00, should be 0xFD.
memory check error at 0x0145C631 = 0x00, should be 0xFD.
memory check error at 0x0145C632 = 0x00, should be 0xFD.
memory check error at 0x0145C633 = 0x00, should be 0xFD.

and the first adress byte is the adress of the first element of my array (so it's normal that it is 0 because I want the first Data1 in the the first element of the array to be 0)!!

Can someone help me ??
Thanks

Re: Memory check error

Neville Franks23-Apr-03 2:45

Neville Franks

23-Apr-03 2:45

cedric moonen wrote:
STRUCT_EXAMPLE* pPtr = new STRUCT_EXAMPLE[NewValue];

Shouldn't this be: STRUCT_EXAMPLE** pPtr =

I'd change your code to use vector<struct_example*> ...

Neville Franks, Author of ED for Windows. www.getsoft.com
Make money with our new Affilate program

Resolved

Cedric Moonen23-Apr-03 2:53

Cedric Moonen

23-Apr-03 2:53

No, I want to use an array of structures, not use the pointers (so they are automatically destroyed) !

But, I found the error: I made a mistake elsewhere in my code and I write "outside" an array. In fact I write on the memory allocated by the bebugger (debug mode) just before the array (STRUCT_EXAMPLE* pPtr). So, that made the compiler go crazy Smile | :)

Format Options - BOLD?

Anonymous22-Apr-03 20:34

Anonymous

22-Apr-03 20:34

is there any any anyway to set the (SourcecodeWindow) keywords on bold?
i have used years the Borland C++ Builder, and the style is very good. black bold C++ keywords.

so is there any way? Smile | :)

Always use memcpy instead of strcpy?

George222-Apr-03 20:33

George2

22-Apr-03 20:33

Hi, everyone!

I think memcpy is faster than strcpy and they really
do the same thing. So I think we should not use memcpy
instead of strcpy.

Am I correct?

Thanks in advance,
George

Re: Always use memcpy instead of strcpy?

jhwurmbach22-Apr-03 21:45

jhwurmbach

22-Apr-03 21:45

You can use memcpy when you want to copy a 'raw' piece of memory. There is no such thing as a concept of a C-string ( null-termination) or even objects in it.
When you want to work with strings it is best to use std::string (or CString if you like) and not to work with strcpy or the like at all.

My opinions may have changed, but not the fact that I am right.

Re: Always use memcpy instead of strcpy?

George222-Apr-03 23:35

George2

22-Apr-03 23:35

Thanks, jhwurmbach buddy!

I am always using strncpy in C++ program. How to use
std::string to do string copy? Do you mean this way,

Source code:
--------
string src = "abc";
string des = src.substr (0, 2);
--------

regards,
George

Re: Always use memcpy instead of strcpy?

jhwurmbach23-Apr-03 1:24

jhwurmbach

23-Apr-03 1:24

Yes, if the first two letters are what you want.
You can make a std::string from a LPCTSTR returned by the API simply by saying e.g.

LPCTSTR s = GetWindowText();
std::string t (s);

the other way round is:

SetWindowText( s.c_str() );

YOu can read more about std::string (and CString) in the Codeproject C++ FAQ.

My opinions may have changed, but not the fact that I am right.

Re: Always use memcpy instead of strcpy?

George223-Apr-03 1:54

George2

23-Apr-03 1:54

Thanks, jhwurmbach buddy!

George

Re: Always use memcpy instead of strcpy?

Tim Smith23-Apr-03 4:10

Tim Smith

23-Apr-03 4:10

strcpy copies a given block of memory up to the point it finds a "0" or NULL in the memory block. strncpy will do the same thing up to a given number of charaters. memcpy will copy the given number of characters.

Assume you wanted to copy the following data:

ABCDE\0MNOPQ

Notice, that there is a NULL character in the 6th position.

strcpy (dst, src) would result in: ABCDE\0
strncpy (dst, src, 8) would result in: ABCDE\0
strncpy (dst, src, 3) would result in: ABC
memcpy (dst, src, 3) would result in: ABC
memcpy (dst, src, 8) would result in: ABCDE\0MN

If you want to copy raw data, use memcpy. If you want to copy C-strings (instead of std::strings) use strcpy or the safer strncpy.

Tim Smith

I'm going to patent thought. I have yet to see any prior art.

Re: Always use memcpy instead of strcpy?

George224-Apr-03 0:17

George2

24-Apr-03 0:17

Thanks, Tim buddy!

George

How to resume the file download

Gowrishankar A.22-Apr-03 19:58

Gowrishankar A.

22-Apr-03 19:58

Problem:

while downloading a huge file from a ftp server, if my service lost the connection in between, how can i resume the download?

The problems are
1: Since it is a huge file, it is not a good idea to restart the download.
2: If we are download by parts in different threads, then each thread should have different connection. This will not work when the server restricts the number of users.

Anybody please suggest a better algorithm for this.

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