C / C++ / MFC

scchan19844-Aug-05 22:37

scchan1984

4-Aug-05 22:37

Really really thank you so much.
I have to improve and test my code now Big Grin | :-D

scchan19844-Aug-05 23:42

scchan1984

4-Aug-05 23:42

My improved version:
WCHAR* UnicodeCharToBigEndianConverter(char* message)
{
// get the number of WCHAR from the message
int nInputLen = MultiByteToWideChar(
CP_ACP, // code page
0, // character-type options
message, // string to map
-1, // number of bytes in string
NULL, // wide-character buffer
NULL // size of buffer
);

WCHAR* input = new WCHAR[nInputLen+1];
WCHAR* output = new WCHAR[nInputLen+1];

MultiByteToWideChar(
CP_ACP, // code page
MB_COMPOSITE, // character-type options
message, // string to map
-1, // number of bytes in string
input, // wide-character buffer
nInputLen+1 // size of buffer
);

// escape character for unicode
output[0]='\xFE\xFF';

for(int i=1;i<=nInputLen;i++)
{
output[i] = ((input[i-1] & 0xFF) << 8) | ((input[i-1] & 0xFF00) >> 8);
//output[i] = input[i-1];
}

output[nInputLen+1] = 0;

return output;
}

Jose Lamas Rios5-Aug-05 6:19

Jose Lamas Rios

5-Aug-05 6:19

It's much better now Smile | :)

Note that you are allocating two buffers. You are returning one of them as the result. The other should be deleted before returning, to avoid leaking memory. Add the following line before the return:

delete[] input;

You should note that the callers of this function are responsible for deleting the result...

Besides that, it seems to be already doing what it's supposed to do. Now, if you want to do it really right, keep reading...

First I reccomend you read the following article by Joel Spolsky: The Absolute Minimum Every Software Developer Absolutely, Positively Must Know About Unicode and Character Sets (No Excuses!)
[^]

Now that you have read it (if not, go and read it, I'll wait right here), you surely understand why a name like UnicodeCharToBigEndian[...] doesn't make much sense for what this function does (i.e.: it's not receiving an Unicode string, but a multibyte string.)

A better name would be MultiByteToBigEndianWideChar...

One additional problem with your function is that it returns a buffer that must be released by the caller. This is a problematic approach because as a user of the function, I couldn't deduce that from the function signature alone.

If all I see is a function declared in a header file as

WCHAR* MultiByteToBigEndianWideChar(char* message);

I have no way to know whether I should delete the returned buffer or not, or in case I'm expected to delete it, whether I should use delete[], free, or anything else. I'd have to rely on some documentation or on having access to the implementation itself in order to find out.

To avoid this ambiguity, it's a common practice in this kind of functions to make the caller supply the buffer and its size as parameters to the function. When the buffer is supplied by the caller, the caller already knows if that buffer is allocated in the stack or in the heap, and how to release it in the latter case. That's exactly the approach followed by MultiByteToWideChar and all the API functions.

In fact, you might start with a function with exactly the same parameters as MultiByteToWideChar

int MultiByteToBigEndianWideChar(
  UINT CodePage,         // code page
  DWORD dwFlags,         // character-type options
  LPCSTR lpMultiByteStr, // string to map
  int cbMultiByte,       // number of bytes in string
  LPWSTR lpWideCharStr,  // wide-character buffer
  int cchWideChar        // size of buffer
)
{
   int nResult = MultiByteToWideChar(
                   CodePage,
                   dwFlags,
                   lpMultiByteStr,
                   cbMultiByte,
                   cchWideChar? lpWideCharStr + 1 : 0,
                   cchWideChar? cchWideChar-1 : 0
                 );
 
   if (cchWideChar != 0)
   {
      lpWideCharStr[0] = 0xFEFF;
      WideCharToBigEndian(lpWideCharStr, nResult+1);
   }
 
   return nResult + 1;
}

When cchWideChar is 0, it calls MultiByteToWideChar with 0, and returns its result plus 1, because this function will need to add a byte order marker (BOM) at the start of the buffer).

When cchWideChar is not 0, it calls MultiByteToWideChar to make the conversion to Unicode, leaving the first position available for the BOM, then puts the BOM at the first position, and calls WideCharToBigEndian, which simply does the byte swapping in the same buffer it receives.

void WideCharToBigEndian(LPWSTR lp, int cchWideChar)
{
   for(int i = 0; i < cchWideChar; i++)
      lp[i] = ((lp[i] & 0xFF) << 8) | ((lp[i] & 0xFF00) >> 8);
}

Now your function can be used exactly like MultiByteToWideChar, including the option to query a buffer size, and with the same flexibility (i.e.: all the options in code page, flags, etc.) You can refer anyone to the documentation for MultiByteToWideChar and simply state that you add a BOM and convert the unicode string to big-endian.

Now suppose you want to provide a simplified version in which some of the options are filled with default values.

int MultiByteToBigEndianWideChar(
  LPCSTR lpMultiByteStr, // string to map
  LPWSTR lpWideCharStr,  // wide-character buffer
  int cchWideChar        // size of buffer
)
{
   return MultiByteToBigEndianWideChar(
                   CP_ACP,
                   MB_COMPOSITE, // by the way, are you sure you want this flag as default?
                   lpMultiByteStr,
                   -1,
                   lpWideCharStr,
                   cchWideChar
                 );
}

There, now you only need to compile and test. Good luck!

--
jlr
http://jlamas.blogspot.com/[^]

scchan19844-Aug-05 22:31

scchan1984

4-Aug-05 22:31

I got the answer!!!

The reason is that when I change the ASCII character to big-endian, take 'B', with unicode \x42\x00, it become \x00\x42.

And I used strlen to check the string length of (char* UnicodeCharToBigEndianConverter(char* message)), which finds the terminating character \x00, and gives me the wrong string length!!

My code in the above post should be ok.
Anyone interested in have a look in it and test it.

WinSpy for Java Applications

Nemanja Trifunovic4-Aug-05 6:55

Nemanja Trifunovic

4-Aug-05 6:55

MultibyteToWideChar[^]

My programming blahblahblah blog. If you ever find anything useful here, please let me know to remove it.

Member 17897714-Aug-05 5:20

Member 1789771

4-Aug-05 5:20

Hi,

Is there any application which tells the component class of the Java application which is similar to WinSPY ?

If anybody know please let me know.

thanks,
Mahender

ftp

Aditya Rao4-Aug-05 4:51

Aditya Rao

4-Aug-05 4:51

hi,
i am trying to create a ftp application in which i want to show the progress bar. i tried using the OpenFile of CFtpConnection to open the file and then read it. but the problem i am facing is that whenever i try to get the file size by using the SeekToEnd function which returns the file size i get an exception. and i think that the file is not being opened properly. can anyone help me. i have used IIS for the ftp adn created a virtual directory. the name of the computer in IIS is : homepc. so how should i give the file path( what should be the path of the file : suppose the file to be copied is test.txt what should be the exact path). also can anyone provide any example for the same. is there any other way to use a progress bar in this application

thanks

aditya

question about DEBUG setting

valerie994-Aug-05 4:07

valerie99

4-Aug-05 4:07

morning,

my debug will let error like "access violation" by pass when I keep going by breakpoints, it says "first exception handles....", but I think the access violation is the window error, it will crash in release version, not sure why my debug is not picking it up as "unhandled exception"

thank you!

toxcct4-Aug-05 5:11

toxcct

4-Aug-05 5:11

and what is the exception thrown ???

and what is the code that make the crash ?

TOXCCT >>> GEII power
[toxcct][VisualCalc]

valerie994-Aug-05 5:26

valerie99

4-Aug-05 5:26

the exception will be like :

"First-chance exception in Epred.exe: 0xC0000005: Access Violation."

crash because the code couldn't recorgnize and return data type

thanks

toxcct4-Aug-05 5:28

toxcct

4-Aug-05 5:28

can we have a piece of the crashing code to understand what you're doing wrong ?

TOXCCT >>> GEII power
[toxcct][VisualCalc]

how to control windows shutdown?

ThatsAlok5-Aug-05 1:42

ThatsAlok

5-Aug-05 1:42

valerie99 wrote:
"First-chance exception in Epred.exe: 0xC0000005: Access Violation."

This mean you application try to access the memory which is actually not available.

try to debug and check is every Varible getting required memory ?

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

Proxy Server UDP, TCP

Robert M Greene4-Aug-05 3:59

Robert M Greene

4-Aug-05 3:59

I am looking for a free proxy server to redirect UDP and TCP Traffic for a brief test.

A free UDP/TCP proxy server or source code for same would be cool as well. C++, VB (Gah!), C#, VB.Net, anything like that would work.

Doesn't have to be the greatest thing in the world, just something that can handle a few tests. The OS platforms would be a windows server, NT, 2000, 2003 server, any of those.

The reason I need it on windows is because the VP client to perform the tests is windows only.

Thanks!

.............................
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.

Fiat justitia, et ruat cælum

ThinkingPrometheus4-Aug-05 1:54

ThinkingPrometheus

4-Aug-05 1:54

hiho@ll

i just wanted to know if it's possible to "hook" the windows shutdown and if yes how?

i thought about a simple alarm prog, which does something if you want to shutdown windows

for example it checks if you did some task before shutdown
or it simply reminds you to do something before shuting down

anybody has an idea?

thx@ll

Re: how to control windows shutdown?

ThatsAlok4-Aug-05 2:42

ThatsAlok

4-Aug-05 2:42

ThinkingPrometheus wrote:
i thought about a simple alarm prog, which does something if you want to shutdown windows

HANDLE WM_QUERYENDSESSION message !

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

Re: how to control windows shutdown?

ThinkingPrometheus4-Aug-05 3:28

ThinkingPrometheus

4-Aug-05 3:28

maybe i'm wrong but if i handle such an event, windows will try to kill the application if it doesn't exit!?

so is it possible to abort the shutdown if i use WM_QUERYENDSESSION?

Re: how to control windows shutdown?

ThatsAlok4-Aug-05 6:26

ThatsAlok

4-Aug-05 6:26

ThinkingPrometheus wrote:
so is it possible to abort the shutdown if i use WM_QUERYENDSESSION?

Yeap it possible, you just return the FALSE o this event and then you have to shutdown by your self!

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

double clicking an icon on taskbar

Ankit Aneja4-Aug-05 1:44

Ankit Aneja

4-Aug-05 1:44

hello to all members i have been given task to add functionality in project

on right clicking icon on taskbar it shows menu like windows messenger shows
Exit,open,signout,sign in,sign in as,my status,send an email message and my e-mail Inbox
my project icon is also showing its menu like that
but on double clicking windows messenger icon in taskbar messenger gets opened
how will i add this double clicking functionality to my project

Ankit Aneja

Eytukan4-Aug-05 2:33

Eytukan

4-Aug-05 2:33

Ankit Aneja wrote:
windows icon in taskbar it gets opened

?

V

Ankit Aneja4-Aug-05 3:02

Ankit Aneja

4-Aug-05 3:02

i mean when i double click windows messenger icon on task bar it gets opened
same functionality i want here

Ankit Aneja
"Nothing is impossible. The word itself says - I M possible"

ThatsAlok4-Aug-05 2:41

ThatsAlok

4-Aug-05 2:41

Ankit Aneja wrote:
on right clicking icon on taskbar

I Believe you are talking about System Tray!

Ankit Aneja wrote:
but on double clicking windows icon in taskbar it gets opened

Handle the Function associated With the System Tray Message! , you Will get what you want!

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

Ankit Aneja4-Aug-05 3:39

Ankit Aneja

4-Aug-05 3:39

thanks

Ankit Aneja
"Nothing is impossible. The word itself says - I M possible"