C / C++ / MFC

Re: How to pass variables among dialogs in a dialogs based program?

14-Jul-02 22:53

You need to define a variable in the first dialig that will hold the value that you want to pass to the second dialog. In the second dialog, define a variable that will receive the value from the first. For example:

class CMyDlg1
{
public:
int m_x; // this is going to be passed to other dialogs
};

class CMyDlg2
{
public:
int m_x; // this is going to be received from CMyDlg1
}

Somewhere in CMyDlg1, you have a button or menu item that when pressed CMyDlg2 is displayed:

CMyDlg1::OnButton1()
{
CMyDlg2 dlg;
dlg.m_x = m_x; // passing a value from CMyDlg1 to CMyDlg2
dlg.DoModal();
}

Old Gun15-Jul-02 3:32

Old Gun

15-Jul-02 3:32

Mel:
Thank you very much,Your help is very valuble for me,Ilike to program in VC at my amature time,I like to do something I interesting.
thanks.

Re: How to pass variables among dialogs in a dialogs based program?

Anonymous21-Sep-02 12:10

Anonymous

21-Sep-02 12:10

How about doing it the other way around? Ex. using a settings dialog that will change a variable in the main window?

RegisterWindowMessage

Hans Ruck14-Jul-02 21:04

Hans Ruck

14-Jul-02 21:04

I'm analyzing the possibility of using RegisterWindowMessage in order to establish communication between two applications.
Is this the best way to accomplish such task? It looks like the easiest one.

rechi

Re: RegisterWindowMessage

567890123414-Jul-02 21:18

5678901234

14-Jul-02 21:18

Registered message or PostMessage(HWND_BROADCAST, ...) are the most simple ways to communicate between GUI applications, if information you need to send can be placed to wParam, lParam.

a Dialog dll OnTimer Problem

Wade H.14-Jul-02 20:36

Wade H.

14-Jul-02 20:36

I have just created a DLL that has a CreateDisplay funtion that I wanted to be able to pass a time-out value to. When the CreateDisplay function is called, everything is ok BUT the timer functionality. The CreateDisplay function calls a modal dialog that contains 2 text fileds and a hidden button. The dialog created in an MFC App with the same code works fine. (meaning, I know that the settimer and ontimer code is ok). I have thrown in MsgBoxes during the dll's settimer and ontimer code. If the timer message is thrown BEFORE the dialog is drawn, then I get OnTimer hits, however, once it is displayed, I get nothing (spy++ shows nothing as well). And, from the message trick, I know the settime is getting set when I want it to.

So what is my problem???

If it is a message pump thing due to the dll, can someone point me as to what I need to do. (relizing I have never done it)

Thanks.

Application library.

WREY14-Jul-02 20:07

14-Jul-02 20:07

After adding the application library to the same folder under which the application itself is located, from Project->Settings->Link under 'Object/library modules', I entered the directory and subdirectory path information. However, when I tried building the program, it produced an error stating it couldn't open one of the files.

The file to which the error is referring, is right there in the library, and is under the same directory as the program itself.

Because this is a local library used only for this application (and one other), I don't want to use Tools->Options->Directories to enter path information for an application I won't be using too often.

Might someone know why the program isn't seeing the file? (No ".dll's" are involved here.)

Running VC++ 6.0

Thanks.

William

Ancient Dragon14-Jul-02 23:11

14-Jul-02 23:11

We have all probably had that identical problem. It usually caused either mispelling the name of the *.lib or entering the wrong path to it.

1. If the *.lib is located in the project's root directory you do not need to provide the path.
2. Make sure you spelled it correctly.
3. If you want to include the path, make sure the path is correct.

WREY15-Jul-02 9:12

15-Jul-02 9:12

Your reply reflects the experience of someone who has walked that path before. However, take my word for it, they are not applicable in this case since they were the very first set of things I checked.

The file the application says it cannot open, is actually in the 'Include' folder which is a subdirectory of the same directory under which the application subdirectory is located. IOW, library folder, 'Include' folder, and application folder, are all subdirectories of the same directory (which is a subdirectory of the root directory).

I even did a Build->Clean to ensure no leftover baggage is what might be responsible for what's happening. It didn't solve the problem.

Something else I noticed. No matter how many times I changed Project->Settings under "Settings For:" from Win32 Release to Win32 Debug (and press OK), after I run the application, Win32 Debug gets changed right back to Win32 Release.

Because I didn't write all of the code, I'm wondering whether in some obscure place, somebody left something in it that's causing this.

I sometimes use terminology which I do purely for the convenience of communication. For example, I named the folder "DaoLib" where I have the 'Include' folder defined under, then another folder (likewise defined under) containing the "*.lib" file, and thirdly, the application folder (likewise defined under) that contains the dozen or so '.h' files, '.cpp' files, and resource files (etc.). My use of the word "library" was meant to indicate the "DaoLib" folder.

Thanks.

William

Ancient Dragon15-Jul-02 12:09

15-Jul-02 12:09

Since I don't know your directory structure, lets assume it is like this:

c:\DaoLib
c:\DaoLib\include
c:\DaoLib\lib
c:\DaoLib\ProjectFiles (*.cpp, *.h *.rec, *.dsw, etc)
When you compile, the current directory is actually c:\DaoLib\ProjectFiles, So in Project | Settings | C++ Tab | Cateroy "Preprocessor", "Additional Include Directories" you should have "..\include". And in Project | Settings | Link Tab, Category "Input", "Additional Library Path", you shoud have "..\lib"

Whenever you open Project | Settings, the dropdown for Settings For always reflects the Current Active Configuration, either Release or Debug (or some other configuration you may have added to the project).

WREY15-Jul-02 12:31

15-Jul-02 12:31

Thanks Mel, I've gotten passed all that already. I had to do the physical hardcoding of the path (e.g. "..\DaoLib\Include" etc.) for each of the '#include' statements the compiler was saying it couldn't find the file.

I've done all that already, and it works. (To be honest, I'm not a big fan of hardcoding directory information in the '#include' statements, and was looking for a simpler way through using Project->Settings->etc.) But those problems are now history.

The one that's happening now is coming from the linker which says it cannot find the *.obj file.

Thanks for any help.

William

WREY15-Jul-02 10:46

15-Jul-02 10:46

I gave up in the end and hard-coded the shortened form of the directories in each "#include" statement for which the compiler was saying it couldn't find the '.h' files. This got me through the compile part of the build, but now I have a new error which says the linker cannot find the *.obj file.

Confused | :confused:

William

WREY15-Jul-02 11:37

Re: How long is a string ???

15-Jul-02 11:37

I've set the Active Configuration to Win32 Debug, but still have the linkage problem.

William

How long is a string ???

Christian Graus14-Jul-02 19:53

Christian Graus

14-Jul-02 19:53

Does anyone know the maximum possible size of a std::string ?

Christian

come on all you MS suckups, defend your sugar-daddy now. - Chris Losinger - 11/07/2002

Joaquín M López Muñoz14-Jul-02 19:59

Joaquín M López Muñoz

14-Jul-02 19:59

Theoretically at least, std::string::max_size() is such value.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Re: How long is a string ???

Michael Dunn14-Jul-02 20:01

Michael Dunn

14-Jul-02 20:01

Given the layout of Win32 memory spaces, I'd say 2 GB Smile | :)

--Mike--
Just released - RightClick-Encrypt v1.3 - Adds fast & easy file encryption to Explorer
My really out-of-date homepage
Sonork-100.19012 Acid_Helm

Re: How long is a string ???

567890123414-Jul-02 20:03

5678901234

14-Jul-02 20:03

You can call max_size function to check this. On my computer this function returns maximum value for UINT type.

Book suggestion

RK_200014-Jul-02 18:08

RK_2000

14-Jul-02 18:08

What's a good book for building multithreaded applications in windows specifically and C++ generally?

i came across this book "Object-Oriented Multithreading Using C++
Author: Cameron Hughes, Tracey Hughes "..is this worth it? or is there any other ones out there that could be better?

thanks

Re: Book suggestion

Ancient Dragon14-Jul-02 23:14