Re: Question when writing an Assert function - C / C++ / MFC Discussion Boards

How to send a shortcut from a program to the desktop

Larry Mills Sr13-Jan-06 14:26

13-Jan-06 14:26

I would like to know how to send a shortcut to the desktop from within a program?

Can anybody give me a working example?

C++ is my favorite programming language

Re: How to send a shortcut from a program to the desktop

KellyR13-Jan-06 14:51

KellyR

13-Jan-06 14:51

There's an article about it here:

http://www.codeproject.com/shell/desktopshortcut.asp[^]

Kelly Ryan

Accessing MFC classes in VB

mohanrajh13-Jan-06 14:14

mohanrajh

13-Jan-06 14:14

Hi,
I have a VC++(mfc) classes written especially as base class for enhancing menu's in MFC modules.

Now i want to make use of this classes(vc++)for enhancing menu's in a vb6.0 module aswell. So these classes will be accessed by mfc & vb at same time.

1. How do i do this, do i create a dll?, if so what dll?, there are diff options in MFC wizard, which one do i choose to create?

2. Do i need to make any modifications in existing classes to export to VB

Please anyone give me an Idea.

Thanking you

Mo

Re: Accessing MFC classes in VB

includeh1013-Jan-06 18:02

includeh10

13-Jan-06 18:02

what does your MFC class do?
just some menu functions (i.e. delete menu item) or a visible menu interface?

A nice tool for optimizing your Microsoft html-help contents.

Includeh10

Re: Accessing MFC classes in VB

mohanrajh14-Jan-06 0:13

mohanrajh

14-Jan-06 0:13

It loads different menu's from resource(.rc) according to the doctemplate & adds icon to it,plus adds some other enhancments.

Mo

-- modified at 6:55 Saturday 14th January, 2006

VS2005 Dialog Editor -> Add Variable - Control Id field is blank

Yak7713-Jan-06 12:47

Yak77

13-Jan-06 12:47

I am extremely fed up with the resource editor in VS2005. Not only does it regularly crash VS2005 (usually when adding a new dialog), I am now having problems adding a variable from the dialog editor to an associated class.

My Setup in my solution:

- I have a resource only dll that contains only the resources and not the code behind it. In other words it basically only has Resource.rc file and Resource.h file.

- Another project (a library) contains the source code associated with the dialogs and property pages in the Resource.rc file.

- The way I associated the Resources with the code was by adding the Resource.rc file into the other project (the library) and then excluding it from the build.

This seemed to work at first. When I go to add an event handler for say a button, the handler gets added just fine into the correct .cpp and .h file that corresponds to the dialog that contains the button.

The issue I am having is, when I right click on the same button and select "Add Variable", the "Control Id" field is blank and disabled. The Control Id of the button is supposed to be filled in. Why is this happening? If it can add a handler properly, why can't it add a variable?

Also, is there a better way of associating the resources with the code when the resources are contained in a resource only dll and the code in a separate project?

Please Help. This has been frustrating me ever since we upgraded VS 6.0 to VS 2005.

Thanks in advance.

Question when writing an Assert function

Nacho Chip13-Jan-06 12:30

Nacho Chip

13-Jan-06 12:30

Hello all,

I am writing an assert function and don't know how to do certain things,

1. How can I know the file name of the code that cause the assert?
2. How can I know the line number of the code that cause the assert?
3. How can I know the function name of the code that cause the assert?
4. How can I print out the call stack when I get the assert?
5. Can I get the PC and SP register information when I get the asset?

Thanks!

Nacho

Re: Question when writing an Assert function

Stephen Hewitt13-Jan-06 18:58

Stephen Hewitt

13-Jan-06 18:58

1. How can I know the file name of the code that cause the assert?
  A: The "__FILE__" macro.
2. How can I know the line number of the code that cause the assert?
  A: The "__LINE__" macro.
3. How can I know the function name of the code that cause the assert?
  A: Possible but hard - See 4.
4. How can I print out the call stack when I get the assert?
  A: There are article on the codeproject and else where on this - It is a bit involved.
5. Can I get the PC and SP register information when I get the asset?
  A: Inline assembler:

#pragma optimize("y", on) // Force use of frame pointers
DWORD GetMyReturnAddress()
{
    DWORD ReturnAddress;
    __asm
    {
        mov eax, [ebp+4]
        mov dword ptr[ReturnAddress], eax
    }
    return ReturnAddress;
}
#pragma optimize("", on) // Resets the optimizations

// To get EIP and ESP.
DWORD _ESP;
__asm
{
    mov dword ptr[_ESP], ESP
}
DWORD _EIP = GetMyReturnAddress(); // Return address of statement after "GetMyReturnAddress()"

Steve

Re: Question when writing an Assert function

Gary R. Wheeler15-Jan-06 5:24

Gary R. Wheeler

15-Jan-06 5:24

1: The __FILE__ macro.

2: The __LINE__ macro.

3: The __FUNCTION__ macro.

4: This requires that you be able to manipulate the symbolic debugging information for the program in question. Essentially, you have to be able to do the same things as a debugger. This is not trivial, and requires detailed specifications of the debugging symbols, which isn't always available.

5. Yes. Generally, in C, on entry to any given function the top-most item on the stack is the return address. Just above the return address are any function arguments. Since you are now inside your assert function, and you (I would assume) know the arguments, you can 'back up' the stack pointer to reach the stack contents at which your assert function was called.

The question remains, why are you implementing your own assert function?

assert is provided for you.

Software Zen: delete this;

Fold With Us![^]

Re: Question when writing an Assert function

Harold Bamford16-Jan-06 11:52

Harold Bamford

16-Jan-06 11:52

Gary R. Wheeler wrote:
The question remains, why are you implementing your own assert function?

assert is provided for you.

I don't know Nacho's reason, but I have the need to be able to comprehensively report an error (file, line, function, and stack trace) and then continue the program with error recovery.

The idea is that a customer could snap the info and report it back and then I would have a fighting chance of figuring out the problem. And if automatic error recovery worked, then the customer is not facing a complete crash like assert() gives.

Further, not all code runs under Windows. An heretical thought, but there it is! Laugh | :laugh:

Re: Question when writing an Assert function

Gary R. Wheeler17-Jan-06 16:13

Gary R. Wheeler

17-Jan-06 16:13

Harold Bamford wrote:
not all code runs under Windows

assert is a Standard C/C++ library feature, and it not Windows-specific.

Software Zen: delete this;

Fold With Us![^]

Re: Question when writing an Assert function

Harold Bamford19-Jan-06 4:40

Harold Bamford

19-Jan-06 4:40

But it does cause an abort. Not always a nice thing for an embedded system. Thus the need to write an alternative.

LAN API

Allad13-Jan-06 11:52

Allad

13-Jan-06 11:52

Hi,
I'm writing a network application and I need to retrieve informations about network computers : MAC address, Host Name, IP, shared resources...
I suppose something suitable exists in Microsoft API but I don't know where.
I've tried Windows Networking but it seems a bit limitated.
Can someone help?
Thanks

Re: LAN API

zubair_ahmed13-Jan-06 19:46

zubair_ahmed

13-Jan-06 19:46

Winsock API in MSDN will be a good place to look for the information you require.

Z.A

Re: LAN API

ThatsAlok15-Jan-06 19:12

ThatsAlok

15-Jan-06 19:12

zubair_ahmed wrote:
'06

Winsock API in MSDN will be a good place to look for the information you require.

AFAIK and IMHO, Using Winsock api you can only transfer data, you cannot recv any network or lan related data.

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

Re: LAN API

ThatsAlok15-Jan-06 19:10

ThatsAlok

15-Jan-06 19:10

Allad wrote:
I'm writing a network application and I need to retrieve informations about network computers : MAC address, Host Name, IP, shared resources...

look for IPhelper apis

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

How to call CView::OnUpdate

elephantstar13-Jan-06 8:10

elephantstar

13-Jan-06 8:10

I have a window or dialog box (class derives from CFormView) that needs to be updated when the mouse is clicking on any of the items in the menu bar or when the focus leaves the dialog box. There are two cases:

(1) When there are other child windows open in the app, is there an OnKillFocus that I can call to do the update?
(2) Also, when the window is the only open window in the application, and the user selects a menu item, KillFocus will not work since it's still the active window. How do I know the focus is now on the menu bar?

Thanks!

Re: How to call CView::OnUpdate

John M. Drescher13-Jan-06 11:30

John M. Drescher

13-Jan-06 11:30

Call CWnd::UpdateDialogControls and it will process all OnUpdate messages for your window.

John

Re: How to call CView::OnUpdate

FarPointer13-Jan-06 23:51

FarPointer

13-Jan-06 23:51

Hi.
<small>How do I know the focus is now on the menu bar?</small>
you can do a WM_NCHITTEST Notification it returns a ,HTMENU if its on a menu ,( the DefWindowProc function returns that ) if its an HTMENU you can do your concerned work ,i guess this might help you.

Regards
FarPointer.

CComboBox GetItemDataPtr ( problem found )

Maximilien13-Jan-06 5:35

Maximilien

13-Jan-06 5:35

I have a small problem that I cannot find concerning GetItemDataPtr/SetItemDataPtr for the ComboBox.

I do something like this to insert an item :

/// p is a struct that also contains a name
void MyCombo::InsertString( MyPointer* pMyPointer  )
{
  int iIndex = AddString( pMyPointer ->name );
  SetItemDataPtr( iIndex, pMyPointer );

// if I do a GetItemDataPtr here, to test, the pointer is valid.
}

and this to get the data.
/// p is a struct that also contains a name

MyPointer* MyCombo::InsertString( int iIndex )
{
  // index is valid.
  MyPointer* p = ( MyPointer*) GetItemDataPtr( iIndex );
}

at this point, the pointer in the combobox is invalid ( 0x00000001 ) Confused | :confused:

I'm not certain where to start looking for clue to why this happens.

Thanks for info, tips, insights.

Max.

Edit :
Ok, Found the problem, someone else is doing a SetItemData somewhere else, and overwrites the pointer !!!! D'Oh! | :doh:

Maximilien Lincourt
Your Head A Splode - Strong Bad

-- modified at 13:33 Friday 13th January, 2006

COleVariant Empty bstrval

TWS_Dave13-Jan-06 5:34

TWS_Dave

13-Jan-06 5:34

I am getting data from a database via CDaoRecordset. The data is coming back in a COleVariant from which I am reading it. However some of the fields in the database are empty which means the COleVariant is also empty. When I try to read an empty COleVariant the program crashes. This occurs when I try to convert the data to a string or date etc.

CString vData;
COleVariant vVarData;

vData = V_BSTRT(&vVarData); //crashes here if the string is empty!!

This works perfectly if the database field and thus the COleVariant is not empty. Does anybody know how to detect an empty COleVariant before trying to actually read it?

Your help would be appreciated

Dave Collins

Re: COleVariant Empty bstrval

James R. Twine13-Jan-06 6:58

James R. Twine

13-Jan-06 6:58

   You should be checking the type of the underlying VARIANT object to see if its type is VT_EMPTY or not. You can use the V_VT macro for this.

   IMHO, you should be validating the type of the VARIANT before trying to obtain its value.

   Peace!

-=- James

If you think it costs a lot to do it right, just wait until you find out how much it costs to do it wrong!
Tip for new SUV drivers: Professional Driver on Closed Course does not mean your Dumb Ass on a Public Road!
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Re: COleVariant Empty bstrval

Stephen Hewitt14-Jan-06 2:22

Stephen Hewitt

14-Jan-06 2:22

If you're using the V_BSTRT macro to access the data you should check that the data in the variant is actually a BSTR using the V_VT macro, like this:

<code>if ( V_VT(&vVarData) == VT_BSTR )
{
    CString vData = V_BSTRT(&vVarData)
}
else
{
    // Not safe to use "V_BSTRT(&vVarData)" here - Data not a BSTR!
}

If you use it as a BSTR when it's not you're effectiely doing a cast. For example, if the variant contains data of type VT_I4 and you treat it as a BSTR something this like is happening:

<code>UINT i = 4; // Represents the data in the variant.
CString s = reinterpret_cast<BSTR>(i)

Which would be bad.

Steve

Re: COleVariant Empty bstrval

TWS_Dave14-Jan-06 4:57

TWS_Dave

14-Jan-06 4:57

Hi Guys

Thanks for the advice

I tried validating using VT_Empty but discovered that the COleVariant was coming through with the vt value set to VT_NULL. By checking for both VT_EMPTY and VT_NULL I can manage the reading fo the data in a sensible way.

Also thanks for the comment about checking that the varinat is BSTR - I have added this to my code. One day I will grow up to be a real programmer!!

Cheers Guys - Hope I can return the help one day...

Dave Collins Smile | :)

Shockwave Flash Control

zubair_ahmed13-Jan-06 3:31

zubair_ahmed

13-Jan-06 3:31

How can i detect that a flash movie has finished/completed in shockwave flash control,so that i can load a new movie?
thanx in Advance.. Smile | :)

for those who dont know that how it is related to VC,the answer is i am using shockwave object in vc,so i need to handle it in vc. Smile | :)

zubair ahmed

-- modified at 23:36 Friday 13th January, 2006

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