C / C++ / MFC Discussion Boards

VanHlebar3-Nov-03 7:18

3-Nov-03 7:18

I am not sure this is the best place to put this thread so I apologize ahead of time if it should have been posted in the embedded section.

I have an application that I would like to port over to VC++. What is the easiest way to port the project and does anyone have any tips that I can use?

I have not used any specific methods or API that are found only in wince, but I would like to be able to have only one code base for ease of future development. Also it would be nice to be able to take advantage of the increase in screen real estate on the desktop that I didn't have on the ppc. Everything in the ppc applciation was coded using unicode also.

Thanks for the help,
-Eric

GetFolderFromID() from Namespace

johnxx3-Nov-03 6:47

johnxx

3-Nov-03 6:47

Hello,
the thing is still Outlook Automation.
After I could create an new Item just as an subfolder in the Inbox I
need to store some messages in this "NewFolder".
Therfore I need a reference to this folder - but how can I get it ?

In the VB Documentation I can see a function calls
GetItemFromID(LPCTSTR EntryIDItem, const VARIANT& EntryIDStore)

The Problem by using this is the second value.
I don´t know what to do !

Is there anyone in this Forum who can give me a subtle hint in what I have to do.
I little bit code and some encouraging words would be wonderful !

The MSDN is full of VB and VBA Code; but there are only few examples for C++.

Thanks a lot,
John

Default name file in serialization

doctorpi3-Nov-03 5:37

doctorpi

3-Nov-03 5:37

Hi guys
What I have to do to change the default file name in Save Dialog in an SDI app?
Best Regards
Doc

Re: Default name file in serialization

Markyg3-Nov-03 10:34

Markyg

3-Nov-03 10:34

First override the OnFileSave (and OnFileSaveAs if you want to) menu handlers, then just set the name of the default file that you want into the following variable;-

m_strPathName = _T("Whatever");

m_StrPathName is used by the CDocument save functions to work out what file name is presented to the user. If the m_strPathName is empty then the name of the document is used as a basis for the file name. So alternatively you can just call

SetTitle(_T("Whatever"));

instead, although this will not necessarily put the extension you would like onto the document by default, if you have more than one anyway.

Hope this helps,

Mark

vector and delete

ns3-Nov-03 5:32

3-Nov-03 5:32

I have a cDialog class that I spawn with new MyClass in another class (MainClass), and I push_back this m_pMyClass pointer on a vector. Now from another location I wanted to delete and zero out the pointer and I tried:

delete myGlobalVector[i];

 myGlobalVector[i]= 0;

This didnt seem to do it.

So then I did,

delete MainClass.m_pMyClass;

  MainClass.m_pMyClass = 0;

and this worked.

I am puzzled. I thought the first approach would work too..............?? Confused | :confused:

Thanks,
ns

Re: vector and delete

valikac3-Nov-03 5:44

valikac

3-Nov-03 5:44

How does the first solution not work?

Kuphryn

Re: vector and delete

ns3-Nov-03 5:54

3-Nov-03 5:54

After I do the delete and NULLing I have a test:

if (!m_pMyCLass)m_button.EnableWindow(TRUE);

but my button doesnt get enabled if I delete it the first (vector) way. The debuuger tells me that indeed the pointer is not zero at this point!

Thanks for helping.

Re: vector and delete

jhwurmbach3-Nov-03 6:32

jhwurmbach

3-Nov-03 6:32

ns wrote:
if (!m_pMyCLass)m_button.EnableWindow(TRUE);

Please show your actual code.
What you did write here does not use your vector at all!

Who is 'General Failure'? And why is he reading my harddisk?!?

Re: vector and delete

ns3-Nov-03 7:52

3-Nov-03 7:52

I push_back m_pDLGSettings onto the vector. Then I get rid of it as below . Then I test it:

void CImageDisplay::OnBsettings()
{
m_pDlgSettings = new CDlgSettings ;

if (m_pDlgSettings == NULL) return;

BOOL ret = m_pDlgSettings->Create(IDD_DLGSETTINGS, this);

m_pDlgSettings->ShowWindow(SW_SHOW);

pDlgSettingsVector.push_back(m_pDlgSettings);

m_bSettings.EnableWindow(FALSE);

}
In another place where I want all windows to destroy and zero out:

    if( pDlgSettingsVector.size())
    {
        for (int i =0; i < pDlgSettingsVector.size(); i++)
        {
            pDlgSettingsVector[i]->DestroyWindow();
            delete pDlgSettingsVector[i];
            pDlgSettingsVector[i]=0;
}

        pDlgSettingsVector.clear();
    }

and in a function of the class that the index [i] refers to:

if (!m_pDlgSettings)
{
    m_bSettings.EnableWindow(TRUE);
}

I didnt use the vector here because I dont have the location of the pointer in that vector at this point in code. Instead I access it directly, feeling assured that Ithough deleted it using an index, I can always use it by its name instead of its position in the vector. (m_pDLgSettings is a member). In the place I want to check it (last snippet) I am not using its vector position but its actual variable that I pushed onto the vector..........

Hope I am not hopelessly unclear....
Smile | :)

Thanks,
ns

Re: vector and delete

TFrancis3-Nov-03 8:42

TFrancis

3-Nov-03 8:42

The item in the vector is actually a copy of the pointer. In other words, you have two pointers to the CDlgSettings object, m_pDlgSettings and pDlgSettingsVector[0].

While push_back() does pass the object by reference, it makes a copy of the object (in this case a CDlgSettings*) to place in the vector. Thus you are setting one pointer to the CDlgSettigns object to NULL, but the other one still points to the now deleted object.

Possible work around - make the vector contain pointers to pointers, thus the vector will contain a pointer to m_pDlgSettings.

Hope this helps,

Tim

thanks! Trying it out now......

ns3-Nov-03 8:53

3-Nov-03 8:53

Thanks!!!
Thats a subtle point I was unaware of. Appreciate the workaround suggestion. I am trying it out. Not quite sure what I'll be deleting if I delete the vector element. Its a pointer to a pointer so do I delete *(pDlgSettingsVector[i]) ? i.e. the contents of the pointer contained in the vector.

Thanks,
ns

Re: thanks! Trying it out now......

souldog3-Nov-03 9:42

souldog

3-Nov-03 9:42

No, No, No..

Don't do this. Do not store the pointer returned by new anywhere else except the vector.
All access to that object should be through the pointer stored in the vector. Your problem
here is that you have many copies of the pointers floating around. You need to redesign your
application so that this is not the case.

if the code is inside the class pointed to then it should not be possible to call it in any other
way except through the pointer stored in the vector, so you don't need to check it for NULL
This is how it should be done.

ANy other way and you have
Code that is very hard to maintain and very error prone.

Can you explain why and how you are possibly calling a function in a class the instantiation of
has just been deleted from memory.

Re: thanks! Trying it out now......

ns4-Nov-03 2:04

4-Nov-03 2:04

Thanks.

To clarify, if I understand your ending question , I needed to see in some other function whether any windows of the sort I pushed onto the vector exist.

REgarding the prog structure, I later realized that I didnt need a global vector (dangerous anyways) since I was always able to get the object that had the window as a member, so I could iterate trough the parent windows and get t o the member windows (which I had been poushing back) through the pointers to the parents.
MAny thanks for the help!
ns

Struggling with Regex

DimkaSPB3-Nov-03 5:27

DimkaSPB

3-Nov-03 5:27

Hi,

I am using regex to lookup some data in a string. I do not have any prior experience using regular expression and would appreciate some help on the subject.

Here is my expression:
[^\.]\[(\s*\w+\s*)+\]

I am using it to match a string with square brackets where the first character is not a dot. So in the following string "[TableName].[FieldName]" I will only want to find "[TableName]". In "[Table1] INNER JOIN [Table2] ON [Table1].[Field1] = [Table2].[Field2]" I expect to find "[Table1]" and "[Table2]".

This seems to work in some cases, but miserably fails in others. For example, in the following string "[Table1], [Table2]", it only finds "[Table2]" since it expects to see some characted before the bracket.

Basically I want it to look at the first character before "[TableName]" only if there is one. I guess I need to make [^\.] optional but I was not able to find this option with regex syntax. Please help.

Thank you.

Re: Struggling with Regex

Michael Dunn3-Nov-03 5:33

Michael Dunn

3-Nov-03 5:33

The part in square brackets can be matched with

\[\s*\w+\s*\]

To say "not following a dot" you need to use a look-behind assertion. With your expression, the non-dot character gets matched as part of the regex, which isn't what you're trying to get.

(?<!\.)\[\s*\w+\s*\]

This is perl 5 syntax, not sure what environment you're using.

--Mike--
Ericahist [updated Oct 26] | CP SearchBar v2.0.2 | Homepage | RightClick-Encrypt | 1ClickPicGrabber

Re: Struggling with Regex

DimkaSPB3-Nov-03 7:32

DimkaSPB

3-Nov-03 7:32

Michael,

Thank you for you reply. I am using Perl5 syntax and I was using this tool to test the expression: http://jakarta.apache.org/oro/demo.html. I guess, they just did not implement it there, because I kept getting an error (Malformed Regular Expression: Sequence (?<...) not recognized. )

Do you know any other tool I can use to test the expression.

Thanks.

Re: Struggling with Regex

Michael Dunn3-Nov-03 7:41

Michael Dunn

3-Nov-03 7:41

I don't know about anything other than Perl, sorry. The assertions like (?Ericahist [updated Oct 26] | CP SearchBar v2.0.2 | Homepage | RightClick-Encrypt | 1ClickPicGrabber
Pinky, are you pondering what I'm pondering?
I think so Brain, but if we shaved our heads, we'd look like weasels!

dumb question

K. Shaffer3-Nov-03 5:19

K. Shaffer

3-Nov-03 5:19

Im trying to allocate a string in C(non-MFC) of a specified length.
I get an error message:

illegal constant expression

when trying to create buffer.

void parse(const int size)
{
char buffer[size];

...

}

This seems very simple, but I have tried everything. How do I go about doing this?

Kevin Shaffer
kshaff03@msn.com

Re: dumb question

David Crow3-Nov-03 5:23

David Crow

3-Nov-03 5:23

char *buffer = (char *) malloc(size);

Five birds are sitting on a fence.
Three of them decide to fly off.
How many are left?

Re: dumb question

Michael Dunn3-Nov-03 5:27

Michael Dunn

3-Nov-03 5:27

The size of the array has to be known at compile time, so it can't be a variable. You need to use malloc or calloc instead.

--Mike--
Ericahist [updated Oct 26] | CP SearchBar v2.0.2 | Homepage | RightClick-Encrypt | 1ClickPicGrabber
There is a saying in statistics that a million monkeys pounding on typewriters would eventually create a work of Shakespeare. Thanks to the Internet, we now know that this is not true.

Re: dumb question

K. Shaffer3-Nov-03 5:37

K. Shaffer

3-Nov-03 5:37

Thanks!

Kevin Shaffer
kshaff03@msn.com

Re: dumb question

Maxwell Chen3-Nov-03 16:47

Maxwell Chen

3-Nov-03 16:47

<small>kshaff03 wrote:</small>
void parse(const int size)
{
char buffer[size];

...

}

I think it valid in C99, not in C++.

Maxwell Chen

Re: dumb question

Alton Williams5-Nov-03 0:26

Alton Williams

5-Nov-03 0:26

The problem is in your code

kshaff03 wrote:
void parse(const int size)
{
char buffer[size];
...
}

The problem lies in the way you've declared the array.

since char buffer[] is a static array meaning the compiler needs to know at compile time so it knows how much memory to allocate.
You're using a variable to size it. Where you should a constant or literal.
e.g.

#define MAX 100<br />
const unsigned int size = 50;<br />
<br />
inr main(void)<br />
{<br />
char foo[MAX];<br />
char bar[size];<br />
int fred[20];<br />
}

these 3 are all legal
your example should be coded as follows
void parse(const unsigned int &size)
{
char *buffer = new char[size];

...
delete[] buffer;
}

I'll send you an e-mail shortly

MDI application & DLLs

mfcbeginer3-Nov-03 5:06

mfcbeginer

3-Nov-03 5:06

Hi,

I am trying to built an MFC application with an MDI Frame (CWinApp). Beside this, I have implemented a DLL in which I need to open an MFC based Dialog. Within the EXE, I just need to call DoModal and it works fine but here, the function that creates the dialog is in the DLL that is called by the main application.

It crashes in the function int CWnd::RunModalLoop(DWORD dwFlags) with an unhandled exception.

// pump message, but quit on WM_QUIT
if (!AfxGetThread()->PumpMessage())
{
AfxPostQuitMessage(0);
return -1;
}

By the way, I put Debugmultithreaded Dll in the settings of the application and the DLL.

What did I made wrong, please ????

MFC Beginer

Serialization questions

Alton Williams3-Nov-03 4:35

Alton Williams

3-Nov-03 4:35

I have two questions pertaining to serialization.

I have nested classes but want save each class into seperate files how do go about doing this

If want to able to open files in range of different extensions e.g *.csv, *.prn and *.txt. How is this achieved?

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