Re: Book Recommendation - C / C++ / MFC Discussion Boards

uday kiran janaswamy7-Dec-06 2:47

7-Dec-06 2:47

Hi all,

I am operating a Tab to Move the Controls in the Dialog, how can i detected that the Control is got Focused when i am using a Tab Control.

Example:

i am having three controls in a Dialog, i am pressing a Tab in the Key Board then the Cursor moves to all the Controls, here how can i detect that the Control have moved to the Third Control.

Any Ideas with GetFocus(...) Api,

Please help me out.

Uday kiran

Re: Problem with GetFocus

Rajesh R Subramanian7-Dec-06 3:16

Rajesh R Subramanian

7-Dec-06 3:16

Handle the WM_KEYDOWN event and check if its the tab key.

Nobody can give you wiser advice than yourself. - Cicero

Re: Problem with GetFocus

David Crow7-Dec-06 5:14

David Crow

7-Dec-06 5:14

uday kiran janaswamy wrote:
...how can i detect that the Control have moved to the Third Control.

Any Ideas with GetFocus(...) Api,

if (GetFocus() == GetDlgItem(hDlg, IDD_THIRD_CONTROL))
    ...

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"Judge not by the eye but by the heart." - Native American Proverb

Re: Problem with GetFocus

uday kiran janaswamy7-Dec-06 18:13

uday kiran janaswamy

7-Dec-06 18:13

Hi David,

I am very Much Thankfull to give a great idea, Thanks a Lot.

Uday kiran

Book Recommendation

Revant Jain7-Dec-06 2:35

Revant Jain

7-Dec-06 2:35

Hello,

I wanted to start learning WIN32API. Now before that could anyone pls recommend me a good C book. I am familiar with basics of C. If I read a C++ book, would that make a difference?

Thank you

Re: Book Recommendation

Sam Hobbs7-Dec-06 3:20

Sam Hobbs

7-Dec-06 3:20

All new programs should be written using C++, so you should learn it first. You should learn C just to be able to read other people's code.

It is better to learn C++ first without learning Windows programming. Then when you are familiar with C++ learn Windows programming.

Re: Book Recommendation

toxcct7-Dec-06 5:01

toxcct

7-Dec-06 5:01

Don't know where to start ?
Refer the Forums Guidelines and ask a friend

[VisualCalc 3.0][Flags Beginner's Guide]

Re: Book Recommendation

Sam Hobbs7-Dec-06 11:20

Sam Hobbs

7-Dec-06 11:20

I don't need to start.

Perhaps you meant to reply to Revant Jain, the person asking the question.

Re: Book Recommendation

ThatsAlok7-Dec-06 18:04

ThatsAlok

7-Dec-06 18:04

Sam Hobbs wrote:
t is better to learn C++ first without learning Windows programming. Then when you are familiar with C++ learn Windows programming.

good!

<div class='ForumSig'>"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 Support CRY- Child Relief and you </div>

Re: Book Recommendation

Hamid_RT7-Dec-06 18:18

Hamid_RT

7-Dec-06 18:18

I want to know its my problem or no,did you change your sig ? Smile | :)

WhiteSky

Re: Book Recommendation

ThatsAlok7-Dec-06 18:29

ThatsAlok

7-Dec-06 18:29

Forget to turn HTML oN Smile | :)

... how are you HAMID.. sorry belated hAPPY EID

"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
Support CRY- Child Relief and you

Re: Book Recommendation

Hamid_RT7-Dec-06 18:51

Hamid_RT

7-Dec-06 18:51

Thanks after two hard weeks today is holiday with a cloudy weather,by the way How are you? tommarow is holiday for you Big Grin | :-D

WhiteSky

Re: Book Recommendation

Hamid_RT7-Dec-06 17:55

Hamid_RT

7-Dec-06 17:55

In additional see www.cplusplus.com Smile | :)

WhiteSky

loading an image

Sunil P V7-Dec-06 2:29

Sunil P V

7-Dec-06 2:29

Hi all,

I am using pure c++ functions in visual studio 2005 to create a window which behaves similar to a dialog.
I have the handle to this window. Does anyone know how to load an image to this window? the image can be either a gif/bmp format???

Sunil

Sunil

Re: loading an image

C^hris L^osinger7-Dec-06 8:32

C^hris L^osinger

7-Dec-06 8:32

if you're just reading BMP, you can use LoadImage.

for GIF, you'll have to use one of the many imaging toolkits that are available. (or GDI+, if you can use that in your app)

image processing | batch image processing | blogging

Re: loading an image

Hamid_RT7-Dec-06 17:59

Hamid_RT

7-Dec-06 17:59

You can use of CImage class

WhiteSky

CFile does not open

BadJerry7-Dec-06 2:27

BadJerry

7-Dec-06 2:27

Here is the following code part of a COM object (in Visual C++ 6.0)

<br />
   CFile filXML;<br />
   CFileException e;<br />
   if ( !filXML.Open(strFile,CFile::modeCreate | CFile::modeWrite | CFile::typeBinary,&e ) )<br />
   {<br />
      TCHAR lpError[256];<br />
      e.GetErrorMessage(lpError,255);<br />
      // Cannot open file<br />
      CString strError;<br />
      strError.Format(_T("Cannot create file '%s' Cause:%d OS error:%ld Error:'%s'"),strFile,e.m_cause,e.m_lOsError,lpError);<br />
<br />
      if ( pstrError != NULL )<br />
      {<br />
         if ( (*pstrError) != NULL )<br />
            SysFreeString(*pstrError);<br />
         *pstrError = strError.AllocSysString();<br />
      }<br />
<br />
      *pnResult = ERR_CANNOT_CREATE_FILE;<br />
      return S_OK;<br />
   }<br />
<br />

This has always worked. On one installation (called by an ASP.net application) CFile::Open returns false except I get 0 for the cause and -1 for the OS error. The file name seems fine (asp.net can create a file of that name)
Any idea why?

Re: CFile does not open

prasad_som7-Dec-06 2:39

prasad_som

7-Dec-06 2:39

This is just guess.
If its asp.net web service , it runs under user account(I cant remember its name right now), which has minimum access. May be, that user account has not access permission to file in question.

Prasad
Notifier using ATL | Operator new[],delete[][^]

Re: CFile does not open

BadJerry7-Dec-06 2:45

BadJerry

7-Dec-06 2:45

This is not a web service. And we have granted full write authorisation to every one on the directory which is being written onto. And we can write to it from asp.net. And if CFile:Open fails we should have something in m_Cause. And I am going mad Smile | :)

Re: CFile does not open

prasad_som7-Dec-06 3:12

prasad_som

7-Dec-06 3:12

CFile::Open uses CreateFile internally, to create file on disk. This function fails in two scenario, first one is obviously failure of CreateFile API, second one is if there is problem with file path( too long ,etc.).
It uses _AfxFullPath2 for converting relative path to absolute path. Failure of this function may also be reason.

If you debug CFile::Open, these are three places from where, function is retuning FALSE.

I'm assuming, in your case, execution doesn't reach till CreateFile, as you are not getting useful information from exception object.

Prasad
Notifier using ATL | Operator new[],delete[][^]

Re: CFile does not open

BadJerry7-Dec-06 4:54

BadJerry

7-Dec-06 4:54

I have indeed looked at the source for CFile :: Open in the MFC (for VC98) but I do not get these 3 places where FALSE can be returned. Only 1 and after the CreateFile...
Thanks for your help but I still do not know where to look next.

Re: CFile does not open

prasad_som7-Dec-06 18:22

prasad_som

7-Dec-06 18:22

Ooops ! I looked at VS2005. Seeing your post, I looked in to VC 6.
Did you mentioned earlier that, exception object doesn't tell you anything ?

Prasad
Notifier using ATL | Operator new[],delete[][^]

Re: CFile does not open

Mark Salsbery7-Dec-06 5:44

Mark Salsbery

7-Dec-06 5:44

It may be you are missing a share flag. An open mode and share flag (at least 1 of each) are
required.

try

if ( !filXML.Open(strFile, CFile::modeCreate | CFile::modeWrite | CFile::typeBinary | CFile::shareDenyWrite, &e ) )
{
...

Typecasting incompatible types

WillemM7-Dec-06 2:22

WillemM

7-Dec-06 2:22

I have a question about typecasting incompatible types. I have two handles to objects, the handle class is a template class that functions as a smartpointer implementation.

Handle<A> ahandle(new B);
Handle<B> bhandle;

What I want is to cast from Handle<A> to Handle<B>. B derives from A and as such I can cast between them. The only problem is, I can't cast the handles directly.

I have come up with a solution involving some dirty hacking, but I am unsure if this is going to work and what it will do at runtime.

void* blankhandle = (void*)&ahandle;
Handle<B> bhandle = *(reinterpret_cast<Handle<B> >(blankhandle));

Hope anyone can shed some light on this.

WM.

What about weapons of mass-construction?
"You can always try to smash it with a wrench to fix that. It might actually work" - WillemM

Re: Typecasting incompatible types

Mark Salsbery7-Dec-06 5:57

Mark Salsbery

7-Dec-06 5:57

WillemM wrote:
B derives from A and as such I can cast between them

If this is truly the case then you should have no problem casting between them.
Therefore, you can use the safer dynamic_cast operator to perform the cast.

void* blankhandle = (void*)&ahandle;
Handle<B> *pBHandle = dynamic_cast<Handle<B>*>(blankhandle);
if (pBHandle)
{
	Handle<B> bhandle = *pBHandle;
...
}

Note I checked the return from dynamic_cast. If the object wasn't created as a B type handle
then it would fail as it should.
>

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