C / C++ / MFC Discussion Boards

Re: Virtual KeyCodes error: undeclared identifier

valikac30-Jun-03 6:33

valikac

30-Jun-03 6:33

What key? Post the code and the error.

Kuphryn

Comparison in Preprocessor

chris_mccc30-Jun-03 4:59

chris_mccc

30-Jun-03 4:59

I'm having trouble comparing two Floating Point Const at Compile time. Here is an example:

const Float64 EducationGoal_Original = 0.0;
const Float64 EducationGoal_1_0 = 1.0;
const Float64 EducationGoal_2_0 = 2.0;
const Float64 EducationGoal_CURRENT = EducationGoal_2_0;
.
.
.
#if EducationGoal_CURRENT != EducationGoal_2_0
// return error
#endif

So...basically if someone adds a new EducationGoal version i want to make sure he updated all the code associated with it.

For some reason, the #if will always return true with floating point #s

Any Ideas?

Re: Comparison in Preprocessor

João Paulo Figueira30-Jun-03 5:14

João Paulo Figueira

30-Jun-03 5:14

I'm not sure that the preprocessor can read into a value of a const... Unsure | :~

Anyway, try to replace the const definition by a #define. I know this is not the correct way to create constants, but use it to check if the #if works.

Re: Comparison in Preprocessor

Ryan Binns30-Jun-03 5:14

Ryan Binns

30-Jun-03 5:14

You can't compare like that. To compare in the preprocessor, you need to #define the constants. const floats are not recognised by the preprocessor. Their "value" is 1 if they exist, and 0 if they do not (I think, from memory). To get this to work, use:

#define EducationGoal_Original (0.0);
#define EducationGoal_1_0 (1.0);
#define EducationGoal_2_0 (2.0);
#define EducationGoal_CURRENT (EducationGoal_2_0);
.
.
.
#if EducationGoal_CURRENT != EducationGoal_2_0
// return error
#endif

Even better would be to use integers, separated into major and minor version numbers, since floats are not accurate, and comparing them for equality is not a good idea.

Hope this helps,

Ryan

Being little and getting pushed around by big guys all my life I guess I compensate by pushing electrons and holes around. What a bully I am, but I do enjoy making subatomic particles hop at my bidding - Roger Wright (2^nd April 2003, The Lounge)

Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late - John Nichol "Point Of Impact"

(URGENT !!!!) Sharing Memory between CV++ 6.0 and VB 6.0

Carlo30-Jun-03 4:07

Carlo

30-Jun-03 4:07

Hi all,
I have this big problem:
from an exe written in VB i call a function in a Dll written in VC++. This function must allocate an array of structs ant restitute it initializad to the calling process.
To be more clear I'll write what I would do if the exe is in C++:

The struct could be something like this:
struct _Data
{
int Data1;
VARIANT Data2;
};

In the dll there is a function like this:
extern "C" void WINAPI DLLReadArray(_Data **Array)
{
*Array= new _Data[10];

// For example I fill the array elements whith some data
}

from the VC++ exe I would do something like:
void CallDLL()
{
_Data *Array;
DLLReadArray(&Array);

// Some operations on the array elements...

delete[] Array;
}

NOW:
I do not have any idea on how to do the last thing if the exe is written in VB.

The structure in VB could be declared as a Type ???
Type Data
Data1 As Integer
Data2 As Variant
End Type

How to pass the DLL a "pointer" in VB ????

Please, any help would be very very appreciated !!!
thanks all.

Sorry for my poor english.
Carlo Comino
Italy.

Re: (URGENT !!!!) Sharing Memory between CV++ 6.0 and VB 6.0

basementman30-Jun-03 4:27

basementman

30-Jun-03 4:27

The only method (that i'm aware of) to pass arrays between VB and VC is via SafeArrays. VB uses SafeArrays internally, so the work is on the C side to unpackage/use the data in this format.

onwards and upwards...

Re: (URGENT !!!!) Sharing Memory between CV++ 6.0 and VB 6.0

Carlo30-Jun-03 5:01

Carlo

30-Jun-03 5:01

thank yuo very much for your fast replay !!;)
Do you also have an example of the C part ??
thank you again!!
Carlo.

List Control in ATL/WTL

YaronNir30-Jun-03 4:05

YaronNir

30-Jun-03 4:05

Hi all,

i have an ATL project. i've created a dialog that inherites CAxDialogImpl.
in the resources of the dialog i've placed a list control.

is there a class that wrapps it in ATL? same as CListCtrl in MFC???

can any1 help?

thanks in advanced,

Yaron

Ask not what your application can do for you,
Ask what you can do for your application

Re: List Control in ATL/WTL

João Paulo Figueira30-Jun-03 4:47

João Paulo Figueira

30-Jun-03 4:47

Check the WTL header (AtlCtrls.h). There you should find a template <class TBase> class CListViewCtrlT which in turn will be specialized into a CListViewCtrl.

Re: List Control in ATL/WTL

YaronNir30-Jun-03 4:56

YaronNir

30-Jun-03 4:56

thanks man.....

Ask not what your application can do for you,
Ask what you can do for your application

Using Windows Access Control in my application

Mike Eriksson30-Jun-03 4:04

Mike Eriksson

30-Jun-03 4:04

Hello!

I have an application where different groups can do different things. E.g. Group Sales can add an customer. Group Pack can print out a pack order but not add a customer. etc...

I could of cause create my own control system but since Windows already has this kind of system and it is probably much better (security wise) than anything I could create.

How do I use Windows Access Control System in my own application?

I need to be able to create a number of groups and give them rights in my application.

TIA

Anders Eriksson
Sonork 100.21825

Re: Using Windows Access Control in my application

basementman30-Jun-03 4:32

basementman

30-Jun-03 4:32

If this is a SQL Server app, I would suggest looking at the TSQL function IS_MEMBER ({'group' | 'role' }). This provides rights / membership checking of both WindowsNT groups and SQL Server Roles.

Otherwise, you can use the NetGroupXXX functions, but your app needs to be running under certain priviledges and this is a pain.

onwards and upwards...

I wrote the buf[] question, Forgot to login

johnstonsk30-Jun-03 4:02

johnstonsk

30-Jun-03 4:02

Re: I wrote the buf[] question, Forgot to login

Trollslayer30-Jun-03 5:38

Trollslayer

30-Jun-03 5:38

Posted a reply, see below Big Grin | :-D

The tigress is here Big Grin | :-D

XP zip

_Magnus_30-Jun-03 4:01

_Magnus_

30-Jun-03 4:01

Anyone know if there is some API for the zip features in XP? Unsure | :~

/Magnus

- I don't necessarily agree with everything I say

Re: XP zip

Neville Franks30-Jun-03 11:53

Neville Franks

30-Jun-03 11:53

_Magnus_ wrote:
Anyone know if there is some API for the zip features in XP?

I don't think so. There are several articles here at CP re. zip/unzip and you can also look at Crypto++ which has this.

Neville Franks, Author of ED for Windows. Free Trial at www.getsoft.com

Help with understanding the use of a buf[]

Anonymous30-Jun-03 4:00

Anonymous

30-Jun-03 4:00

I don't quite understand how a buffer works.

I have a PCI card that uses reflective memory
Reflective memory is memory that is connected through a daisy chain on fiber optics, when one PC writes to the memory on the PCI card then the rest of the computers on the daisy chain can read what was written in realtime or as close as you can get to it.

I hope that makes sense.

I am able to choose at what offset I want to start writing data to the PCI cards memory.
ex. offset 0x40 from the beginning of the cards memory.

Then on another PC I can go read the data at that offset 0x40.

The data structure that I have created is that needs to be written to memory is:

The data is continious.

<br />
<br />
//this will get written at offset 0x40<br />
 struct TSimHeader<br />
	{<br />
		int SimWriteFlag;			<br />
		int DisplayReadFlag;				<br />
		int SignalCount;		<br />
		int SimStatus;<br />
		long TimeStamp;<br />
	};<br />
<br />
//this will get written right after TSimHeader<br />
struct TSimSignal<br />
	{<br />
		double Min[45];	  <br />
		double Max[45];	  <br />
		double Value[45]; <br />
		char   *Name[45];<br />
		char   *Unit[45];<br />
	};<br />

The functions that read and write the data use a buffer to write and read from (char or int or double or long buf[1024])

How can I put these 2 structures in this buffer so that on the otherside when I read in the data I am able to parse it back out of the structure?

Thanks,
sj Smile | :)

Re: Help with understanding the use of a buf[]

Trollslayer30-Jun-03 5:37

Trollslayer

30-Jun-03 5:37

How about creating a structure

struct TSimBlock<br />
{<br />
TSimHeader header;<br />
TSimSignal signal;<br />
}<br />

then a variable

<br />
TSimBlock *BlockPtr;<br />

then set TBlockPtr to point to the data in the card on the other side and read it for eaxmple by

<br />
i = BlockPtr->header.SimWriteFlag;<br />

Hope I've got all the indirection right, haven't run the code myself.

Elaine Rose | [Rose]

The tigress is here Big Grin | :-D

Re: Help with understanding the use of a buf[]

johnstonsk30-Jun-03 6:20

johnstonsk

30-Jun-03 6:20

Makes sense. I just created a type exactly like the struct that was written.
I then casted the data to the struct type on the other side.
I am then able to read the data just as I was writing it.

Thanks,
For showing me the way.

Sj Smile | :)

Custom Draw in CListCtrl - how to change background of icons?

Dominik Reichl30-Jun-03 3:07

Dominik Reichl

30-Jun-03 3:07

Hello,

I am trying to colorize specific rows of my list control. For this I use the OnCustomDraw member function of CListCtrl to select the color before Windows draws the item. This works very nice, except that the icon's background isn't drawn correctly.

See this screenshot:
http://home.tiscali.de/reichl/temp.jpg[^]

As you can see, the row is highlighted correctly, but the icon's background remains white.

How can I draw the icon's background? Confused | :confused:

-Dominik

_outp(0x64, 0xAD);
and
__asm mov al, 0xAD __asm out 0x64, al
do the same... but what do they do??

Re: Custom Draw in CListCtrl - how to change background of icons?

Ryan Binns30-Jun-03 4:12

Ryan Binns

30-Jun-03 4:12

Did you try drawing the background in OnCustomDraw() during the CDDS_ITEMPREPAINT notification? If that doesn't work, try an earlier notification, such as CDDS_ITEMPOSTERASE or even CDDS_ITEMPREERASE (not recommended, but it might work).

Or is the problem that Windows is drawing the white background no matter what you do? If that's the case, the best thing to do would probably be to get the control to draw in a memory DC and change the colour yourself, although that would probably require full owner-draw.

Ryan

Being little and getting pushed around by big guys all my life I guess I compensate by pushing electrons and holes around. What a bully I am, but I do enjoy making subatomic particles hop at my bidding - Roger Wright (2^nd April 2003, The Lounge)

Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late - John Nichol "Point Of Impact"

Re: Custom Draw in CListCtrl - how to change background of icons?

Dominik Reichl30-Jun-03 6:28

Dominik Reichl

30-Jun-03 6:28

I tried preerase and posterase, but both don't work. The background remains white. Seems as I really have to draw it myself Dead | X|

Anyway, thanks for your help
-Dominik

_outp(0x64, 0xAD);
and
__asm mov al, 0xAD __asm out 0x64, al
do the same... but what do they do??

Re: Custom Draw in CListCtrl - how to change background of icons?

Ryan Binns30-Jun-03 17:14

Ryan Binns

30-Jun-03 17:14

OK, I just happened to look at Michael Dunn's article on list view custom draw (http://www.codeproject.com/listctrl/lvcustomdraw.asp[^]) and he does this by redrawing the icon in CDDS_ITEMPOSTPAINT and returning CDRF_SKIPDEFAULT. It flickers a bit, but not too much.

Ryan

Being little and getting pushed around by big guys all my life I guess I compensate by pushing electrons and holes around. What a bully I am, but I do enjoy making subatomic particles hop at my bidding - Roger Wright (2^nd April 2003, The Lounge)

Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late - John Nichol "Point Of Impact"

Re: Custom Draw in CListCtrl - how to change background of icons?

Dominik Reichl1-Jul-03 0:15

Dominik Reichl

1-Jul-03 0:15

Ok, I'll try this.

Thanks
-Dominik

_outp(0x64, 0xAD);
and
__asm mov al, 0xAD __asm out 0x64, al
do the same... but what do they do??

Re: Custom Draw in CListCtrl - how to change background of icons?

basementman30-Jun-03 4:35

basementman

30-Jun-03 4:35

You could specify an overlay mask which would colorize the background as you wish.

onwards and upwards...

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