double and float variables - C / C++ / MFC Discussion Boards

yanuart12-Apr-04 1:08

12-Apr-04 1:08

I get this error
[code]error C2664: '_variant_t::_variant_t(VARIANT &,bool)' : cannot convert parameter 1 from 'const char [5]' to 'VARIANT &'[/code]
when I tried to create a new variant using this code :
[code]_variant_t varID("myID", VT_BSTR);[/code]
what's wrong ?? as the docs says its okay

Re: Trouble with _variant_t

Milton Karimbekallil12-Apr-04 1:48

Milton Karimbekallil

12-Apr-04 1:48

hi

There is no default constructor for _variant_t that takes the 'value' and 'VT_BSTR' 2gethor... Simply give the value only. So change ur code with the following.

_variant_t varID(L"myID");

rgds..mil10

Are there somewhere good articles about MTS ?

vgrigor12-Apr-04 0:53

vgrigor

12-Apr-04 0:53

I need to know all main features of MTS,
in details suffitient for passing exam
MCSD 70-015 Distributed C++,

I need articles desribing in some parts
following program:

(Read english topics)

http://www.stars-s.ru/course.asp?c_no=48&d_no=141
or
http://www.stars-s.ru/course.asp?c_no=48&d_no=17330

Do someone know good articles about ISAPI,
in a looking like that program?

Very need.

Thanks.

unsigned chars

packetlos12-Apr-04 0:10

packetlos

12-Apr-04 0:10

Hi guys,

I am trying to copy into a struct the contents of a buffer returned from the winpcap library, the libray function call returns a pointer to the buffer like the following type:

const UCHAR *pkt_data

I am trying to declare something to hold the data where // Packet data ??? is.

typedef struct DATAGRAM
{
	UINT packetID;			// Sequence Number
	ip_header ipHeader;		// IP header
	pcap_pkthdr wpHeader;	        // Winpcap header
	unsigned char pkt_data[];	// Packet data ???
} DATAGRAM;

I would prefer to keep it as UCHARS because it makes it easier to parse the data later on into headers such as tcp, so my question is how should declare the type in the struct and how can i copy the data in from the buffer??

Cheers

Packetlos

Re: unsigned chars

John R. Shaw12-Apr-04 0:37

John R. Shaw

12-Apr-04 0:37

This "unsigned char pkt_data[];" should not pass the compiler. Insted the stucture should look something like this:

typedef struct DATAGRAM{
	UINT packetID;			// Sequence Number
	ip_header ipHeader;		// IP header
	pcap_pkthdr wpHeader;	        // Winpcap header
	unsigned char pkt_data[1];	// Packet data ???
} DATAGRAM;

Then if you know if you know the nuber of bytes you will be receiving you can allocate the need memory like so:

DATAGRAM* pDatat = (DATAGRAM*)malloc(sizeof(DATAGRAM) + nDataSize) or the C++ equivalent to allocate the need memory and then copy the data into pData->pkt_data as you see fit. If you do not know the data size ahead of time things get a lot more complicated and you may want to use one of the STL templates or if programming using MFC you could replace "unsigned char pkt_data[1];" with "CByteArray pkt_data;". CByteArray stores unsigned chars, because that is what a byte is.

Good Luck1

INTP

Re: unsigned chars

packetlos12-Apr-04 1:21

packetlos

12-Apr-04 1:21

Hi John,

Thanks for taking time to reply, CByteArray seems to be exactly what I need, I can calculate the size of the data and set the CByteArray like this:

<br />
tempDatagram.pkt_data.SetSize(dataLen);<br />

But then how do I copy the data into the array using the given pointer to the buffer of UCHARS?

Re: unsigned chars

packetlos12-Apr-04 5:38

packetlos

12-Apr-04 5:38

Sorted with:

MoveMemory(tempDatagram.pkt_data.GetData(), pkt_data, dataLen);

double and float variables

deniz79s12-Apr-04 0:04

deniz79s

12-Apr-04 0:04

I can't use double and float variables correctly.
When I appoint a float or double values to float or double variables, The variables have 0.0 or 1.0 values. they don't have another values.(for example 0.152 or 0.53 Eek! | :eek:

...)

I don't solve this.
or is there another usage float and double variables? I haven't known

deniz

Re: double and float variables

John R. Shaw12-Apr-04 0:46

John R. Shaw

12-Apr-04 0:46

deniz79s wrote:
or is there another usage float and double variables? I haven't known

No!

double d = 0.0;
double d = 1.0;
double d = 0.152;
double d = 123.456;

float f = 0.0;
float f = 1.0;
float f = 0.152;
float f = 123.456;

should all produce the correct results. Now if you wher trying to do something like "if( d == 1.0 )" you may be having a problem (don't do that!).

INTP

Which DLLs do I have to distribute AND which DLLs can I expect to be already installed on a standard XP installation?

Tony Westminster12-Apr-04 0:04

Tony Westminster

12-Apr-04 0:04

Hello,

it is the first time I have to distribute self-written applications
in Visual C++.

Now I am facing the following problem: My application needs some DLLs
that are not present on a standard Windows XP installation. I know that
because I can run it on my PC where I have installed Visual Studio also. When I run it on a XP-only (without VS) system, it crashes with error code xxx135 which means missing DLL.

Now what I did was using depends 2.1 to see all the DLLs that I need.
However now I do not know which ones of them I have to include with my
application installation routine. All of them would sure be overkill, since there are some standard dlls that are present on all Windows platforms I believe.

But how do I know which DLLs are definitely present and which ones I have to add to my installation package?

Thank you very much for your help.

Tony

Re: Which DLLs do I have to distribute AND which DLLs can I expect to be already installed on a standard XP installation?

Abin12-Apr-04 3:01

Abin

12-Apr-04 3:01

There may not be a definite way to predict which DLL's are already on your customer's system and which are not but basically, if the customer is using Windows2000 or higher versions OS, you may just assume this:

If you did not specifically include any ".lib" files into your project, then you do not need to worry about DLL's, if you did, however, you will need to distribute the corresponding DLL's as well.

One more thing, if you used VC.net to develop your application, then "MFC70.DLL" must be distributed because most OS's(including Win XP) do not have that file by default.

Re: Which DLLs do I have to distribute AND which DLLs can I expect to be already installed on a standard XP installation?

Tony Westminster12-Apr-04 4:10

Tony Westminster

12-Apr-04 4:10

Abin,

thank you very much for that information, that helps a lot.

I was really having a hard time because I used a code example
from codeguru.com on how to get the MAC Address of the PC.

http://www.codeguru.com/Cpp/I-N/network/networkinformation/article.php/c5451

I used Method 3 (GetMACAdapters) and this includes
iphlpapi.lib. Now DependencyWalker showed it relied
on EFSADU.DLL which was not present on XP Home. So I
was very confused. I now learned that although DepWalker
lists EFSADU.DLL (which is called by IPHLAPI.DLL), this
does not mean that it is explicitly linked.

I must say that I have not really understood the concept between
explicitly and implicitly linking, so I will try to learn about
it.

Thank you again,
Tony

ADO Calls and Socket

Sitaram Sukumar11-Apr-04 23:43

Sitaram Sukumar

11-Apr-04 23:43

Hi All,
I have written a server application, which accepts info from other client machine (this for the present is being simulated wthrough HyperTerminal).

After I reviece a packet from the Hyper terminal (comprising of a UserID and Passwd), I check against a DB (I am Using ADO DB Calls). I am trying to open the DB connection and the Recordeset inside the Server thread. Here it fails, (Open returns a FALSE). The DB Calls works well outside the thread.

Can the DB Calls be never made from within a thread..

Please advise. Any Help is appreciated

Re: ADO Calls and Socket

Milton Karimbekallil12-Apr-04 0:50

Milton Karimbekallil

12-Apr-04 0:50

hi
Make sure u have called ::CoInitialize() in the thread.

rgds...mil10

WM_NCMOUSELEAVE Message help

baskarchinnu11-Apr-04 22:10

baskarchinnu

11-Apr-04 22:10

Hello,

I am working on Win32 API platform. I have tried the message "WM_NCMOUSELEAVE" in Win 2000 OS. In 2000 OS the message will not get. but it is working in XP OS Fine. Can u please help me for this problem. I need to get the message (WM_NCMOUSELEAVE) in 2000 OS also.

Thanks in Advance
Baskar

Baskar

Re: WM_NCMOUSELEAVE Message help

Neville Franks11-Apr-04 22:48

Neville Franks

11-Apr-04 22:48

You should use Spy++ to confirm you are correct. My guess is this is not your problem.

Neville Franks, Author of ED for Windows www.getsoft.com and coming soon: Surfulater www.surfulater.com

Re: WM_NCMOUSELEAVE Message help

Neville Franks12-Apr-04 1:23

Neville Franks

12-Apr-04 1:23

According to http://msdn.microsoft.com/library/default.asp?url=/library/en-us/winui/WinUI/WindowsUserInterface/UserInput/MouseInput/MouseInputReference/MouseInputMessages/WM_NCMOUSELEAVE.asp[^] WM_NCMOUSELEAVE works on W2K. However it only works with TrackMouseEvent. I assume you are using that.

Please do not send private emails to me. Instead post here on the forum - thanks.

Neville Franks, Author of ED for Windows www.getsoft.com and coming soon: Surfulater www.surfulater.com

How to add toolbars to IE programatically

NewtonOfComputers11-Apr-04 21:38

NewtonOfComputers

11-Apr-04 21:38

here i am developing an application in which i need to add a button in IE regarding my applicaitons options. How shall i do that.

One more thing is that is it posiible to add buttons or toolbars to .exe files

if possible how shall i do that.

Basheer

Re: How to add toolbars to IE programatically

Prakash Nadar11-Apr-04 22:12

Prakash Nadar

11-Apr-04 22:12

You can search for toolbar here in CP , there are few articles on that Smile | :)

Re: How to add toolbars to IE programatically

SiddharthAtw12-Apr-04 20:17

SiddharthAtw

12-Apr-04 20:17

Use the interface of IE explorer. It is well documented in MSDN.

How to read Unicode data from Oracle in VC?

regzero11-Apr-04 21:14

regzero

11-Apr-04 21:14

Hi,

I have a string like this stored in Oracle "áạà". In degugger, "á" shows 0x00E1 and "à" shows 0x00E0, but "ạ" (0x1EA1) shows 0x00BF. It's changed to "¿" (0x00BF).

Does any one know how to read it?

Thanks.

Exe's involved

SatyaDY11-Apr-04 21:13

SatyaDY

11-Apr-04 21:13

Hi,
I am having one application (developed by someone else). This application involves so many exes. How can I know the order in which these exe's are called by the application when it runs?? Do I need to build the debug version of the application as well as the exe to debug this application and place them respective folder??

I have to fix a bug in the application. How to do that in this scenario??
Regards,
Satya Smile | :)

Re: Exe's involved

Prakash Nadar11-Apr-04 22:11

Prakash Nadar

11-Apr-04 22:11

well simplly you can move all the supporting exes to another folder, and then run the main application, Then it will start complaining about the exes missing and you then come to know the order of the supporting exes called.

Re: Exe's involved

SatyaDY12-Apr-04 0:08

SatyaDY

12-Apr-04 0:08

Hi,
I don't know what are the exes called by the application. That's the problem.

Re: Exe's involved

SiddharthAtw12-Apr-04 20:20

SiddharthAtw

12-Apr-04 20:20

U mean to say that U don't have the code of the application. Then U are trying to do reverse Engineering. If yes? you are going to loose Ur hairs soon.

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