C / C++ / MFC Discussion Boards

Re: How to determine the control under cursor

Arrin7-Apr-11 4:18

Arrin

7-Apr-11 4:18

Hello,

thanks for suggestions, it works with WM_MOUSEWHEEL message!

Best regards
Arrin

Re: How to determine the control under cursor

Arrin7-Apr-11 4:19

Arrin

7-Apr-11 4:19

Hi,

thanks, it works with wm_mousewheel

regards
arrin

Extract text(English & Chinese) from pdf [modified]

wonderway31-Mar-11 16:47

wonderway

31-Mar-11 16:47

I need to extract text from a pdf using C, on platform Linux.
I find "stream" and "endstream",send the string between "stream" and "endstream" to zlib,and uncompress some contents.Then I can analyse the pattern and extract english character correctly,but the problem is I don't know how to handle the Chinese character,I have tryed many charset,but I don't know which charset it uses.
So I need your help about this,such as the detail format of pdf, or the character set and so on.
Thank you!!
Please forgive my terrible English. Smile | :)

wonderway

modified on Friday, April 1, 2011 3:43 AM

Re: Extract text(English & Chinese) from pdf

Peter_in_278031-Mar-11 17:28

Peter_in_2780

31-Mar-11 17:28

I suggest you google 'pdf specification'. The specification will tell you what character set / encoding is used and how it is specified.

Software rusts. Simon Stephenson, ca 1994.

Issue while Use DLL in MFC Exe Application

Andraw Tang31-Mar-11 9:01

Andraw Tang

31-Mar-11 9:01

Hi, dear all,

I create a DLL (we called Server.DLL)with several exported functions, I also create testing application (Client.EXE) to call the exported functions in DLL, both are in debug mode. Everything works fine.

Now I need to create a DLL in release mode, so I use the Server.DLL and Client.EXE for release mode, and change the compiled files for debug mode as Sever_Debug.DLL, Client_Debug.EXE, also in the project setting part of the client application, I change the following settings:
Link ->General->Object/Library modules as Server_Debug.LIB,
Link ->General->Input->Additional Library Path to the server project Debug folder.

After I compile the client application and run the program, I got an error:

The application has failed to start because Server.DLL was not found. Re-installing the application may fix this problem.

My question is that why it still look for Server.DLL, suppose it should look for Server_Debug.DLL, right? Is there any place to let use set the path and name for the DLL file or we just put the DLL file at the same folder as client application exe file, and by default DLL file name should be same as LIB file name, am I right?

Thanks a lots!

Re: Issue while Use DLL in MFC Exe Application

Albert Holguin31-Mar-11 9:28

Albert Holguin

31-Mar-11 9:28

actually your stuff looks ok although its more common to have a debug target folder instead of different name for debug version (MS does have different names though since they distribute both)... do a search for "Server.DLL" in your project, maybe you're referencing the name and don't forget to recompile the server.dll to produce server_debug.dll

Re: Issue while Use DLL in MFC Exe Application

Andraw Tang31-Mar-11 9:33

Andraw Tang

31-Mar-11 9:33

Thanks for reply.

I recompile the DLL in debug mode and also search for Server.DLL in client application, cannot find it. usually when use DLL file, we just set the library file name and path, don't need to directly DLL file name and path, just put the DLL in the same folder as EXE file, right? I don't know from where the client application remember the Server.DLL.

Re: Issue while Use DLL in MFC Exe Application

Albert Holguin31-Mar-11 9:38

Albert Holguin

31-Mar-11 9:38

If you didn't specify the path of the DLL anywhere, it should just look in the same directory as the exe. I'll think about this a little bit to see if I can remember anything that may cause this... did you do a clean recompile?

Re: Issue while Use DLL in MFC Exe Application

Andraw Tang31-Mar-11 10:53

Andraw Tang

31-Mar-11 10:53

Hi, Albert,

Thank you very much, I solve this problem.

The problem is in the .def file, it has LIBRARY : SERVER

so if I want to change the library file to SERVER_Debug, I also need to change the library name in .def file. So I thought your idea is good, no matter in debug or release mode, use the same name, just output the files in debug and release to different folder, so we don't need to modify .def file.

Thanks again.

Re: Issue while Use DLL in MFC Exe Application

Albert Holguin31-Mar-11 11:00

Albert Holguin

31-Mar-11 11:00

ah yes! i should've remembered the module definition file.. glad you fixed your bug and shared the solution! Smile | :)

Anything wrong

Smith#31-Mar-11 4:46

Smith#

31-Mar-11 4:46

<br />
	BYTE message[5];<br />
	message[0] = 15;<br />
	message[1] = 33;<br />
	message[2] = 2;<br />
	message[3] = 23;<br />
	message[4] = 33;<br />
        .<br />
        . <br />
        .<br />
        .<br />
        .<br />
  <br />
	int	messageLengh = 60;<br />
<br />
	char szLogBuff [512]={0};<br />
	for(int i=0;i<messageLengh;i++)<br />
	{<br />
		char chz[4]={0};<br />
		sprintf(chz,"%d ",i);<br />
		strcat(szLogBuff,chz);<br />
	}<br />
        printf(szLogBuff);<br />

Do you find anything wrong with this code?
Do I need to pad the buffer with a '\0'? or just assigning 0 to the buffer initially is fine?

Re: Anything wrong [modified]

Luc Pattyn31-Mar-11 5:17

Luc Pattyn

31-Mar-11 5:17

Smith# wrote:
Do you find anything wrong with this code?
Do I need to pad the buffer with a '\0'? or just assigning 0 to the buffer initially is fine?

~~yes. no. yes.~~

[MODIFIED]
if it really is the indexes you want to print, then it is: no. no. yes. (but why show all the message stuff then?)
[/MODIFIED]

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles] Nil Volentibus Arduum

Please use <PRE> tags for code snippets, they preserve indentation, improve readability, and make me actually look at the code.

modified on Thursday, March 31, 2011 2:26 PM

Re: Anything wrong

Smith#31-Mar-11 5:33

Smith#

31-Mar-11 5:33

The first yes makes me not to click on the x of this window. Could you please tell me what is wrong with the code before I click on x?

Re: Anything wrong

Luc Pattyn31-Mar-11 7:18

Luc Pattyn

31-Mar-11 7:18

Smith# wrote:
char chz[4]={0};

this buffer is too small, your sprintf statement may generate a minus sign, three digits, a space, and a NULL, that is 6 characters.

60 of these could take up to 301 chars, so char szLogBuff [512]={0}; is sufficiently large, and as others already pointed out, your total initialization is a waste, as each strcat will move the initial terminating NULL backwards.

BTW: you could get the correct result with less code, and save some cycles, and never have the bug you had, by having sprintf() fill the final buffer right away; all it takes is a variable pointer as the destination, initialized to szLogBuff, and incremented by the return value of sprintf!

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles] Nil Volentibus Arduum

Please use <PRE> tags for code snippets, they preserve indentation, improve readability, and make me actually look at the code.

Re: Anything wrong

CPallini31-Mar-11 7:37

CPallini

31-Mar-11 7:37

Luc Pattyn wrote:
your sprintf statement may generate a minus sign

No, it cannot. Poke tongue | ;-P

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

Re: Anything wrong

Luc Pattyn31-Mar-11 7:41

Luc Pattyn

31-Mar-11 7:41

from the code snippet I can't tell what the definition of BYTE is, could be signed, could be unsigned; I prepare for the worst. Anyway, it isn't really relevant, the buffer isn't sufficiently large.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles] Nil Volentibus Arduum

Please use <PRE> tags for code snippets, they preserve indentation, improve readability, and make me actually look at the code.

Re: Anything wrong

CPallini31-Mar-11 8:02

CPallini

31-Mar-11 8:02

You didn't read the snippet, did you?
(hint: it sprints the index, the BYTE part is completely insignificant).
Smile | :)

Re: Anything wrong

Luc Pattyn31-Mar-11 8:09

Luc Pattyn

31-Mar-11 8:09

How silly.
So that must be wrong too. Laugh | :laugh:

Luc Pattyn [Forum Guidelines] [My Articles] Nil Volentibus Arduum

Please use <PRE> tags for code snippets, they preserve indentation, improve readability, and make me actually look at the code.

Re: Anything wrong

CPallini31-Mar-11 8:17

CPallini

31-Mar-11 8:17

Re: Anything wrong

CPallini31-Mar-11 5:44

CPallini

31-Mar-11 5:44

The code (albeit not beautiful) is correct.
With szLogBuf[512]={0}; you actually initialize the whole buffer with 0 (that is '\0').
Smile | :)

Re: Anything wrong

Smith#31-Mar-11 5:52

Smith#

31-Mar-11 5:52

Then what is the best way to clear the buffer initially?

Re: Anything wrong

Waldermort31-Mar-11 6:14

Waldermort

31-Mar-11 6:14

Since you are dealing with strings there isn't a need to clear the whole buffer.

char x[100] = { 0 };
internally calls memset. In your case it's a waste of (7 or so not including the loop inside memset) CPU cycles.
char x[100];
x[0] = 0;
initially creates an empty string. Just 1 CPU cycle.

But then, calling functions like strcpy and sprintf don't require the buffer to be empty whereas strcat NEEDS a string (empty or otherwise) to append to.

Waldermort

Re: Anything wrong

Smith#31-Mar-11 6:22

Smith#

31-Mar-11 6:22

whereas strcat NEEDS a string (empty or otherwise) to append to.

so I'll have to memset everything to 0 or initialize everything to 0 right?

Re: Anything wrong

Waldermort31-Mar-11 6:35

Waldermort

31-Mar-11 6:35

No. When dealing with string buffers you only need to set the first char/wchar/tchar to 0.

char myString[100]; // Is a buffer of 100 chars the a string may be copied into.<br />
strcat( myString, "Hello World!" ); // will fail because the buffer is full of junk.<br />
// but<br />
strcpy( myString, "World!" ); // will work because it doesn't care what is in the buffer<br />
myString[0] = 0; // copies an empty string to the buffer<br />
strcat( myString, "Hello World!" ); // appends the string to the empty string ( also sets the character after '!' to \0 or NULL.

The new string is actually 13 chars because there is a 0 at the end.

On another note. You shouldn't be using those string functions. There are safer versions available:
strcpy_s( myString, 100, "Hello World!" );
These check to make sure the buffer is large enough for the string

Also, you might want to read up on TCHAR and the unicode/ansi string functions

TCHAR myString[100];<br />
_tcscpy_s( myString, 100, _T("Hello World!");

Waldermort

Re: Anything wrong

Luc Pattyn31-Mar-11 7:18

Luc Pattyn

31-Mar-11 7:18

CPallini wrote:
The code ... is correct.

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