CString problem - C / C++ / MFC Discussion Boards

David Crow7-Jul-03 2:50

7-Jul-03 2:50

HFILE hFile = OpenFile(..., OF_SHARE_EXCLUSIVE);
if (HFILE_ERROR != hFile)
{
    DeleteFile(...);
}

Calling a VB dll from C++

rajdawg6-Jul-03 12:48

rajdawg

6-Jul-03 12:48

I have followed the instructions for C. Lung's VERY helpful article from 1999 on calling a VB ActiveX Dll from c++. I have built my VB dll that I have (which has 24 classes and 1 .bas file), and I used the midl compiler to compile the .idl file that I made by copying the code crom OLE View, as the article instructs. Now that I have the .idl files and the .c files which correspond to my VB DLL loaded into my C++ project, I get the following error when I try to build (F7) my c++ project.
"fatal error C1010: unexpected end of file while looking for precompiled header directive". I cannot figure out the cause of this error.
The only thing I have done that was not mentioned in Lung's article is change some data type specifications in the idl file which were causing error messages from the midl compiler. I changed "Single" to "float" and, I replaced the name of a VB enum I had created with a "Long" data type.
Please advise, or ask more questions, if I have not provided enough info.
Thank you VERY much, in advance, for any help you can provide!
rajdawg - a.k.a. Roger

Re: Calling a VB dll from C++

Anders Molin6-Jul-03 13:50

Anders Molin

6-Jul-03 13:50

You can find the answar for that error in the FAQ
http://www.codeproject.com/cpp/cppforumfaq.asp[^]

- Anders

Money talks, but all mine ever says is "Goodbye!"

Running in debugger runtime detect?

Brian Tietz6-Jul-03 11:55

Brian Tietz

6-Jul-03 11:55

The product I'm working on is still in the stage where I'm releasing debug builds. I have asserts in place for things that I want to see, but aren't actual application failures. What I'd like to do is augment assert so that places where I want to see an assert, I'll get an assert, but not when a debug build leaves my desk. I could just add a define and have not only a debug build configuration, but also a private debug build configuration. But ideally, I'd like to detect at runtime whether the app is running in the debugger or not, and key this behavior (and a few others I won't go into) off of that information. Does anyone know a way to do this?

Re: Running in debugger runtime detect?

Dave Bryant6-Jul-03 12:09

Dave Bryant

6-Jul-03 12:09

Use IsDebuggerPresent()

Dave
http://www.cloudsofheaven.org

Re: Running in debugger runtime detect?

peterchen6-Jul-03 22:35

peterchen

6-Jul-03 22:35

Brian Tietz wrote:
The product I'm working on is still in the stage where I'm releasing debug builds.

You should never do that Wink | ;)

(and btw. I think it's not allowed to redistribute the debug runtime dll's...)

Here on CP you'll find some tools how to convert your _ASSERT's into release-build log file entries. It's better, really.

"Der Geist des Kriegers ist erwacht / Ich hab die Macht" StS

sighist | Agile Programming | doxygen

Outlook Express Plug-ins

Emilio Guijarro6-Jul-03 3:44

Emilio Guijarro

6-Jul-03 3:44

Hi guys and girls,

Where can I find resources about OE plug-in (or add-in) development? I this feature only avaitable in Outlook 2000 or better?.

Thanks in advance.

"When I look into your eyes, there´s nothing there to see, nothing but my own mistakes staring back at me"

CString problem

andyg.1016-Jul-03 3:01

andyg.101

6-Jul-03 3:01

Hi there, now I have a problem with my buffer.

I have a buffer reading in data from the serial port data is passed into the buffer like this

m_serialbuffer += ch; //where m_etc is a CString and ch is a string read from the serial buffer

Now this works perfectly for the first string that is sent to the port and stores it. For subsequent strings though, no characters are added. Any ideas??
andy

Re: CString problem

John M. Drescher6-Jul-03 3:05

John M. Drescher

6-Jul-03 3:05

Is there a chance for the NULL character '\0'? CStrings are NULL terminated.

John

Re: CString problem

andyg.1016-Jul-03 4:01

andyg.101

6-Jul-03 4:01

what do you mean?

Re: CString problem

John M. Drescher6-Jul-03 4:15

John M. Drescher

6-Jul-03 4:15

If there is a zero (ASCII 0 not the number 0) in the input the CString will not add any more characters.

John

Re: CString problem

andyg.1016-Jul-03 4:20

andyg.101

6-Jul-03 4:20

hmm yes I think there is a zero on the end of the first string. How can I get around this?

Re: CString problem

John M. Drescher6-Jul-03 4:24

John M. Drescher

6-Jul-03 4:24

Either strip the 0 with an if statement or use an array like CArray or vector.

John

Re: CString problem

andyg.1016-Jul-03 4:36

andyg.101

6-Jul-03 4:36

Nice one many thanks

Andy

Re: CString problem

David Crow7-Jul-03 3:01

David Crow

7-Jul-03 3:01

Appending 0-terminated strings to a CString object is expected.

char *name = "David"; // there is an implied \0 at the end of this string<br />
CString str = "My name is ";<br />
str += name;

Re: CString problem

David Crow7-Jul-03 3:04

David Crow

7-Jul-03 3:04

The comment in this code snippet appears to be outdated.

Have you stepped into the code to verify that 'ch' has valid data at the time of appending? When you state that "ch is a string", does that mean it is a string object, or are you using string in the generic sense (e.g., char ch[32])?

error Incorrect Function

andyg.1016-Jul-03 1:36

andyg.101

6-Jul-03 1:36

Hi there, I'm trying to do overlapped IO on the serial port, but since I changed from non-overlapped the readfile and writefile calls fail with error
incorrect function
I changed the following

m_ComPortHndl = CreateFile (sComPort,GENERIC_READ|GENERIC_WRITE,0,
								NULL,OPEN_EXISTING,
								FILE_FLAG_OVERLAPPED,NULL);

i.e. added the file flag overlapped
and also added overlapped structures to the read/write calls

ReadFile( m_ComPortHndl, &nData, 1, &dwBytesRead, &ovRead)

any ideas why I might be getting this??
Andy

Re: error Incorrect Function

andyg.1016-Jul-03 1:44

andyg.101

6-Jul-03 1:44

Scratch that it was because I wasn't initialising the overlapped structures to zero

OVERLAPPED ov = {0};

Andy

how to control networkcard in c/c++!

jobillcai6-Jul-03 0:21

jobillcai

6-Jul-03 0:21

example to forbiden and start it........

error

dudic5-Jul-03 23:39

dudic

5-Jul-03 23:39

what to do if I get an error like:

LINK : fatal error LNK1104: cannot open file "mfc42u.lib"
Error executing link.exe.

Re: error

Ryan Binns5-Jul-03 23:55

Ryan Binns

5-Jul-03 23:55

You probably didn't include the MFC Unicode libraries when you installed VC. Run the install again and install them. Smile | :)

Ryan

"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: error

Michael Dunn6-Jul-03 2:59

Michael Dunn

6-Jul-03 2:59

See the FAQ
2.8 Why do I get an unresolved external on nafxcw.lib or uafxcw.lib?[^]

(yes it applies to your error too; I should update the FAQ title now that I think of it)

--Mike--
"I'm working really, really fast at the moment, so a 3 minute outage becomes, due to time dilation, a 5 minute outage."
-- Chris Manuder, relativistic system administrator
Ericahist | Homepage | RightClick-Encrypt | 1ClickPicGrabber

Question about #pragma pack(1)

George25-Jul-03 21:46

George2

5-Jul-03 21:46

Hi, everyone!

What is the function of "#pragma pack(1)"? Anyone can give
me a simple explanation? Or introduce some materials on this
subject?

Thanks in advance,
George

Re: Question about #pragma pack(1)

Rick York5-Jul-03 22:03

Rick York

5-Jul-03 22:03

Typically the compiler will align members of data structures to their elemental word size. For an integer this means on a four-byte boundary. For shorts it is two, doubles are eight, and bytes are unaligned - they will immediately follow their predecessor.

Sometimes, alignment issues can not be tolerated. Examples are communication interfaces and binary data storage. You must often precisely define where every byte of data is located in these types of applications. #pragma pack(1) means align on a 1 byte boundary or in effect, allow the data to be unaligned.

The Ten Commandments For C Programmers

Re: Question about #pragma pack(1)

George25-Jul-03 22:12

George2

5-Jul-03 22:12

Thanks, Rick buddy!

For example, in the following data structure,

--------
#pragma pack(1)
typedef struct header
{
unsigned indicator:1;
unsigned id:8;
}_header;
#pragma pack()
--------

Suppose indicator will start at address D and I think id will locate
at D + 8 bits for alignment purpose. Am I correct?

regards,
George

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