Re: Converting and Concatenating Strings - C / C++ / MFC Discussion Boards

How Do I Test If A File Is Open By Another Process?

John Clump13-Dec-02 23:08

13-Dec-02 23:08

Here is a simple question I have had a hard time finding an answer for. I have a program which reads and writes MS Jet DB (.mdb) files. I want to make sure that the files are not in use by another process, and the the program has exclusive access to the file. Is there a function that I can use to determine if the file is open or not? Or should I use the CDaoDatabase functions to see if it is use? I assume I should test the file to see if it is open. I know CFile will return an error, but is there a way to test if the file is open before it is opened? Thanks for any help!

Re: How Do I Test If A File Is Open By Another Process?

Nick Parker14-Dec-02 1:50

Nick Parker

14-Dec-02 1:50

John Clump wrote:
Is there a function that I can use to determine if the file is open or not?

I'm sure there is a better way to do this, however you could check for a file with the same name as the database, but with a file extension of ".ldb". This is file that contains record locking information. It appears when your Access application is open and is deleted when Access is closed. Again I think there is probably a better way to do this, but it is another option. Smile | :)

Nick Parker

You see the Standards change. - Fellow co-worker

dialogs not rendering (painting) immeditatly

cleathley13-Dec-02 22:22

cleathley

13-Dec-02 22:22

Hi..

I have notices in my application that dialogs are not rendering (being painted immediatly) after creation..

I am creating my dialog, then i manually show the window (via showwindow) but all I get is a taskbar window icon but nothing on the desktop..

can anybody tell me how to forcibly show the dialog or is there something I can wait for (a signal of sometype). ??

Cheers

Chris

Re: dialogs not rendering (painting) immeditatly

Ravi Bhavnani14-Dec-02 10:55

Ravi Bhavnani

14-Dec-02 10:55

You can force a repaint by doing:

myDialog.Invalidate();
myDialog.UpdateWindow();

/ravi

Let's put "civil" back in "civilization"
http://www.ravib.com
ravib@ravib.com

COM + object pooling in VC7

Christian Graus13-Dec-02 21:44

Christian Graus

13-Dec-02 21:44

I have an ATL dll in VC7 which I want to pool. Options for this are no longer in the list of options for a new project, and although I've gone multi-threaded, the option is still greyed out. Can anyone provide any suggestions ?

Christian

No offense, but I don't really want to encourage the creation of another VB developer. - Larry Antram 22 Oct 2002

C# will attract all comers, where VB is for IT Journalists and managers - Michael P Butler 05-12-2002

Again, you can screw up a C/C++ program just as easily as a VB program. OK, maybe not as easily, but it's certainly doable. - Jamie Nordmeyer - 15-Nov-2002

Simulate Find Target Programatically

Paul Farry13-Dec-02 20:58

Paul Farry

13-Dec-02 20:58

I want to perform the Find Target(shortcut operation) on a File/Link, but I can't seem to find any API informaiton regading it use.

Could someone please shed some light on it.

I can find the parent folder etc, BUT I want explorer to naviagte to the File and Select it, just like the Properties->Find Target does.

Thanks

Converting and Concatenating Strings

KBL13-Dec-02 20:56

KBL

13-Dec-02 20:56

This is for Visual C++.NET..

Suppose I have two Strings.

String1 = C://files
String2 = data.txt

I want to concatenate the two strings while inserting a character between them, to get a new string:

C://file/data.txt

Here the character is an extra "/".

Once this is done, I would like to convert the new string to a char[20].

Does anyone know how to perform this task?

I would be very grateful..

Thanks

KBL

Re: Converting and Concatenating Strings

Christian Graus13-Dec-02 21:42

Christian Graus

13-Dec-02 21:42

If you're using MC++, that's probably a better place to ask, but String s3 = s1 + @"\" + s2; should do the trick. Convert to char[20], I dunno. I refuse to use MC++.

Christian

No offense, but I don't really want to encourage the creation of another VB developer. - Larry Antram 22 Oct 2002

C# will attract all comers, where VB is for IT Journalists and managers - Michael P Butler 05-12-2002

Again, you can screw up a C/C++ program just as easily as a VB program. OK, maybe not as easily, but it's certainly doable. - Jamie Nordmeyer - 15-Nov-2002

Re: Converting and Concatenating Strings

KBL13-Dec-02 21:59

KBL

13-Dec-02 21:59

how would you do it in unmanaged c++. i find that sometimes you can use the same functions..

Re: Converting and Concatenating Strings

Christian Graus13-Dec-02 22:13

Christian Graus

13-Dec-02 22:13

In standard C++ you would use the std::string or CString class.

string s3 = s1 + "\\" + s2;
char c[20];
::strcpy(&c[0], s3.c_str());

Something like that. c_str() returns a const char *, if you want a char array declared on the stack, you'd need to use strcpy or memcpy.

Christian

No offense, but I don't really want to encourage the creation of another VB developer. - Larry Antram 22 Oct 2002

C# will attract all comers, where VB is for IT Journalists and managers - Michael P Butler 05-12-2002

Again, you can screw up a C/C++ program just as easily as a VB program. OK, maybe not as easily, but it's certainly doable. - Jamie Nordmeyer - 15-Nov-2002

Re: Converting and Concatenating Strings

Gary R. Wheeler14-Dec-02 4:54

Gary R. Wheeler

14-Dec-02 4:54

CString String1 = "C://files";
CString String2 = "data.txt";

CString Result = String1 + "/" + String2;

char final_result[20];

if (Result.GetLength() < (sizeof(final_result) - 1)) {
    strcpy(final_result,Result);
}
else {
    // signal error
}

Software Zen: delete this;

where find articel on edit and list control searching?

MyMojo13-Dec-02 20:41

MyMojo

13-Dec-02 20:41

please inform me how if possible.

Hastaluego

Re: where find articel on edit and list control searching?

valikac14-Dec-02 6:50

valikac

14-Dec-02 6:50

One solution is LVFINDINFO structure and FindItem().

Kuphryn

buffer increase & increment in C++/MFC

MyMojo13-Dec-02 20:27

MyMojo

13-Dec-02 20:27

i am have a project to finish but facing difficulty like follows:

i am makes a sound recording program but buffer problems for making more that 30 seconds of recording.

help me please in how doing run time buffer increase and increment.

muchas gracias

Hastaluego

event handler question..

trustno113-Dec-02 18:09

trustno1

13-Dec-02 18:09

hi everybody,

i have a question regarding to event handler.. is it ok to bind multple menu command to a same function? i made a new menu for popup/context menu and some of the menu command is going to have the same functionaliy of the mainframe menu command. i was thinking of sharing the functions among the menu commands.

e.g.
on_command(id_a, onmyclick);
on_command(id_b, onmyclick);

thx in advance, have a nice weekend. Smile | :)

Re: event handler question..

Christian Graus13-Dec-02 19:12

Christian Graus

13-Dec-02 19:12

Yes, that will work fine.

Christian

No offense, but I don't really want to encourage the creation of another VB developer. - Larry Antram 22 Oct 2002

C# will attract all comers, where VB is for IT Journalists and managers - Michael P Butler 05-12-2002

Again, you can screw up a C/C++ program just as easily as a VB program. OK, maybe not as easily, but it's certainly doable. - Jamie Nordmeyer - 15-Nov-2002

Re: event handler question..

Jörgen Sigvardsson13-Dec-02 23:14

Jörgen Sigvardsson

13-Dec-02 23:14

Even better: Let the two menuitems share the same id. Then you don't have two WM_COMMAND mappings.

--
This space for rent.

DDE Execute

Mustafa Demirhan13-Dec-02 17:11

Mustafa Demirhan

13-Dec-02 17:11

Hi,

In one of my programs, I am using DDE in order to run my program as the default program for some type of files. In my CWinApp class I added BOOL OnDDECommand(LPTSTR lpszCommand).

When I double click on the file, everthing works fine if another instance of the program is not running. Double clicking runs the program and calls OnDDECommand. After that, if I do not close the program and double click on other files, everthing works fine again. The problem occurs when I run the program individually. After that, if I double click on a file, OnDDECommand method is never executed. Instead of that, my program gets the focus and the following error message comes out:

Windows cannot find 'my_file_name'. 
Make sure that you have typed the name correctly and then try again. 
To search for a file, click the start button, and then click Search.

This message is show by Windows Explorer. Not by my program. I dont know what the problem is. If no instance of the application is running, everthing works fine. Also, if i start the application by double clicking on an associated file evething works fine again. This happens only when I run the program without any files given as parameter and then double click on a file.

I am looking forward to hearing for your suggestions. Please advise...

Thanks for any helps in advance.
Kind regards

Mustafa Demirhan
http://www.macroangel.com
Sonork ID 100.9935:zoltrix

<nobr>They say I'm lazy but it takes all my time

working in hex

hassani13-Dec-02 17:04

hassani

13-Dec-02 17:04

i found a flag that lets me work with numbers in hex:

std::cout.unsetf(std::ios::dec);
std::cout.setf(std::ios::hex);
int x = 45;
cout<

Re: working in hex

Michael Dunn13-Dec-02 17:13

Michael Dunn

13-Dec-02 17:13

setf and unsetf are members of std::ios_base and work on all streams.

--Mike--
Friday's GoogleFight results: Britney Spears 2,190,000 - Erica Weichers 23 Frown | :(

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My really out-of-date homepage
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Code Navigation

Nikolay Avrionov13-Dec-02 16:52

Nikolay Avrionov

13-Dec-02 16:52

Is there any tool for displaying the #include file hierarch? Something like Understand C++, but more stable. I'm going to write such tool this weekend, if there isn't any.

Thanks.

Re: Code Navigation

Taka Muraoka13-Dec-02 18:28

Taka Muraoka

13-Dec-02 18:28

Doxygen will do something like that although it's probably not what you want.

I wrote a little app years ago to generate makefile depenedencies that you could probably hack to do what you want. Email if you want a copy.

he he he. I like it in the kitchen! - Marc Clifton (on taking the heat when being flamed)

Awasu v0.4a[^]: A free RSS reader with support for Code Project.

What does this mean?

SmilingHeart13-Dec-02 15:50

SmilingHeart

13-Dec-02 15:50

I encounter a warning, when i debug a programe.
The warning message is "User breakpoint called from code at 0x77f97704".I donot know the reason.
When this warning message appears, VC shows a screen of assembly code to me.Please tell me the reason to cause this warning .

I love sea

Re: What does this mean?

Taka Muraoka13-Dec-02 16:25

Taka Muraoka

13-Dec-02 16:25

Is VC stopped at a line that says "int 3"?

You've probably hit an assertion somewhere i.e. done something wrong. Bring up the call stack (ALT-7) and have a look at what was going on at the time. If you press F11 a few times, you might be able to switch back to your original source code as well.

he he he. I like it in the kitchen! - Marc Clifton (on taking the heat when being flamed)

Awasu v0.4a[^]: A free RSS reader with support for Code Project.

Re: What does this mean?

SmilingHeart13-Dec-02 21:56

SmilingHeart

13-Dec-02 21:56

Yes you are right. But i donot know what the assembly codes mean.Have you ever encourted this problem?How can i solve this problem.

I love sea

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