C / C++ / MFC

Naveen23-Jul-06 17:19

23-Jul-06 17:19

Why don't u use fwrite(. It can satisfy all the above requirments.

nave

kitty523-Jul-06 17:33

kitty5

23-Jul-06 17:33

would i do:

<br />
FILE *filename;<br />
ULONG *buffer = NULL;<br />
buffer = new ULONG [10000];<br />
...<br />
fwrite(buffer, sizeof(ULONG), 10000, fileName);<br />
...<br />
delete [] buffer;<br />

Thanks.

Kitty5

Naveen23-Jul-06 17:41

23-Jul-06 17:41

yes..

nave

Re: using fprintf() to store data into a file [modified]

bob1697223-Jul-06 17:40

bob16972

23-Jul-06 17:40

This sounds like a homework assignment.

We don't do homework

kitty524-Jul-06 2:54

kitty5

24-Jul-06 2:54

Actually no... Thanks though.
I've been out of school for quite sometime.
I'm just clearing things up since some of these functions I've never used.

Just because other ppl are more adept at programming doesn't mean the the ones that are teaching themselves to be better at it should be penalized or scoffed at.

thanks for your help though.

Kitty5

-- modified at 8:55 Monday 24th July, 2006

David Crow24-Jul-06 3:46

David Crow

24-Jul-06 3:46

bob16972 wrote:
This sounds like a homework assignment.

Not even remotely.

"Money talks. When my money starts to talk, I get a bill to shut it up." - Frank

"Judge not by the eye but by the heart." - Native American Proverb

unresolved external symbol

David Crow24-Jul-06 3:43

David Crow

24-Jul-06 3:43

kitty5 wrote:
fprintf( fpwrite, buffer );

Should be:

fprintf( fpwrite, "%lu", buffer[0]);
fprintf( fpwrite, "%lu", buffer[1]);
...

"Money talks. When my money starts to talk, I get a bill to shut it up." - Frank

"Judge not by the eye but by the heart." - Native American Proverb

thathvamsi23-Jul-06 16:43

23-Jul-06 16:43

Hi all,
Iam trying to read and write to USB device.
I get an error message
error LNK2001: unresolved external symbol "public: enum FT_STATUS __thiscall CUSBtestDlg::GetStatus(unsigned long *,unsigned long *,unsigned long *)" (?GetStatus@CUSBtestDlg@@QAE?AW4FT_STATUS@@PAK00@Z)
Release/USBtest.exe : fatal error LNK1120: 1 unresolved externals

I tried debugging but in vain.
Can anyone help/ any ideas?

Re: unresolved external symbol [modified]

John M. Drescher23-Jul-06 17:12

John M. Drescher

23-Jul-06 17:12

You need to see why the implementation of CUSBtestDlg::GetStatus(unsigned long *,unsigned long *,unsigned long *) is not in any of your cpp or header files that are included in your project. Have you added all the cpp files in your source folder to the project??

John

thathvamsi23-Jul-06 17:40

23-Jul-06 17:40

Hi John n Naveen,
Thanks for the response.
In the header file I do,

protected:<br />
typedef FT_STATUS (WINAPI *PtrToGetStatus)(FT_HANDLE, LPDWORD, LPDWORD, LPDWORD);<br />
	PtrToGetStatus m_pGetStatus;<br />
	FT_STATUS GetStatus(LPDWORD, LPDWORD, LPDWORD);<br />

in the cpp file, I do

int CUSBtestDlg::Buf_Read(void)<br />
{<br />
DWORD dRxBytes;<br />
	DWORD dTxBytes;<br />
	<br />
	DWORD dEventStatus;<br />
<br />
GetStatus(&dRxBytes,&dTxBytes,&dEventStatus);<br />
}

I get the error message that i mentioned before for this.

But I do the FT_STATUS FT_Read() also in the similar way and that works.

Any sugestion.?

-- modified at 23:41 Sunday 23rd July, 2006

Naveen23-Jul-06 18:02

23-Jul-06 18:02

but where is the definition of the funtion GetStatus(..)?

nave

thathvamsi23-Jul-06 18:14

23-Jul-06 18:14

FT_GetStatus is the FTD2XX_API library funciton.

This is given in the header file ftd2xx.h which is included in the USBtestdlg.h file.

Naveen23-Jul-06 18:18

23-Jul-06 18:18

hoo...So have include the lib file for that api in the project?

nave

thathvamsi23-Jul-06 18:33

23-Jul-06 18:33

have included the ftd2xx.h file as external dependency in the project. so the drivers installed should take care of linking the functions and reading and writing from the device(USB).
I can use their FT_Read and FT_Write functions without any errors.
Infact I have done the same way for GetStatus too.

Naveen23-Jul-06 18:56

23-Jul-06 18:56

u have to include the lib file for the same.

take menu project->Settings

in the link tab, there will be an edit box called object/library modules. Give the name of the lib file there and rebuild the project.

nave

thathvamsi23-Jul-06 20:11

23-Jul-06 20:11

FT_Read and FT_Write and FT_GetStatus are all in the same.
I dont know what I should include now.

Naveen23-Jul-06 20:15

23-Jul-06 20:15

thathvamsi wrote:
are all in the same.

same what?dll?

Actually whats "FTD2XX_API library funciton".Can u give me any link so that i can tell u, to what lib u must link.

nave

thathvamsi23-Jul-06 20:44

23-Jul-06 20:44

I meant the dll.
Its the FTD2xx.dll that links the application software with the USB device.

Naveen23-Jul-06 20:55

23-Jul-06 20:55

have u put the ftd2xx.lib in the place i said in the previous post..

http://www.codeproject.com/script/comments/forums.asp?msg=1591621&forumid=1647#xx1591621xx[^]

nave

thathvamsi23-Jul-06 21:22

23-Jul-06 21:22

Hey,
thanks, I did.
works now.
Thanks for ur help.

Naveen23-Jul-06 17:13

23-Jul-06 17:13

U might have declared a Funtion like "CUSBtestDlg::GetStatus(.)" in the header file ( say USBtestDlg.h ) but the body or funtion definiton is not written. More over u have called that funtion from some else.

Solutions.

Either remove the funtion declaration from the header file or Add the function definition in the CPP file

nave

thathvamsi23-Jul-06 17:54