C / C++ / MFC

Re: A very basic question

5-Sep-07 0:58

Generally a struct is for data only, and yes they can be inherited. You will sometimes see structs derived from the built in windows types. It's not often you will see member functions within a struct, though sometimes the need does arrise, especialy when overiding the comparison operators. Other than that, a structs members are public by default, whereas a class's members are protected.

Hamid_RT5-Sep-07 1:02

5-Sep-07 1:02

Yes its possible on the C++ and C++.Net different is about access level also I think you need to see again about classes and structs so you will be see differences classes and structs.;)

IE question

Mohit19825-Sep-07 0:18

Mohit1982

5-Sep-07 0:18

Is there a way to add a new search engine(top right corner) in IE programmatically?

Re: IE question

Hamid_RT5-Sep-07 1:05

How to retrive the handle of other window.

5-Sep-07 1:05

Can you more explain about search engine in IE,please?

GauranG Shah4-Sep-07 23:31

GauranG Shah

4-Sep-07 23:31

Hello Friends,

Can anybody tell me how to retrive the handle of other window/s which is not the part of our application.
I am using global Mouse hook. and done the following things to get the handle of the window when user clicks on it, but it dont work.
I dont know what is the problem.

please Note I am using Win32 Application

Below is the code I use in Mouse Hook

<br />
...<br />
...<br />
if(wParam== WM_LBUTTONDOWN)<br />
{<br />
	hWndActWnd = GetActiveWindow();<br />
	if(hWndActWnd == NULL)<br />
		OutputDebugString(L"Error, GetActiveWindow()");<br />
        PostMessage(hWndApp,MOUSE_DOWN,(WPARAM)hWndActWnd,0);<br />
}<br />
...<br />
...<br />

And Below is the Code I use in My Application

<br />
...<br />
...<br />
HWND hWnd;<br />
case MOUSE_DOWN:<br />
	     hWnd=(HWND)wParam;<br />
             break;<br />
...

Re: How to retrive the handle of other window.

Waldermort4-Sep-07 23:56

4-Sep-07 23:56

Use WindowFromPoint(), then you can iterate through the parent windows to find the top level window.

MFC Multiple Inheritance

Krishnatv4-Sep-07 22:50

Krishnatv

4-Sep-07 22:50

Why MFC not supporting Multiple Inheritence ?could tell me the reasons , behind the architecture plz.

toxcct4-Sep-07 22:53

toxcct

4-Sep-07 22:53

Krishnatv wrote:
Why MFC not supporting Multiple Inheritence ?

it's C++, so it does.

what makes you say so ?

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Krishnatv4-Sep-07 23:07

Krishnatv

4-Sep-07 23:07

C++ Supports Multiple inheritence...that is OK .

Iam asking why MFC not supports Multiple inheritence.

toxcct4-Sep-07 23:20

toxcct

4-Sep-07 23:20

Krishnatv wrote:
Iam asking why MFC not supports Multiple inheritence

so i reapeat : WTF makes you say so ? D'Oh! | :doh:

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BadKarma5-Sep-07 4:35

BadKarma

5-Sep-07 4:35

MFC does support multiple inheritance.
But its not designed in such a way.
Every(should be most) objects are derived from CObject, but none of them are virtual.
This makes that deriving from two MFC parent classes will result in two different root objects.
This is surely bad for the whole MFC design.

So one might say MFC doesn't support Multiple Inheritance in a Usable way.

Adding your own class(non MFC derived) should work.

codito ergo sum

Matthew Faithfull5-Sep-07 0:01

Matthew Faithfull

5-Sep-07 0:01

One problem with MFC and multiple inheritance is that nearly all MFC classes are ultimately derived from CObject. If you then inherit from 2 MFC classes for a new class it gets 2 copies of CObject internally and which one existing code refers to is then ambiguous. This screws up things like MFC Serialization which rely on funtions inherited from CObject. The reasons why virtual inheritance was not used within the MFC Framework to prevent this being a problem are obscure. Someone with C++ guru status would probably be able to explain it.
I have a feeling that there are ways to make it work with a lot of effort becuase I remember seeing an article on CodeProject that claimed to have a solution. I didn't read it or save a link so you'll need to hunt for it yourself if you're interested.
In most cases multiple inheritance can be avoided anyway by making one of the bases a class member instead and exposing the parts of the interface you want by writing your own wrappers. Have a look at some of the tricks ATL uses aswell with template paremters used for base classes; an alternative powerful technique that can sometimes meet your requirements instead of using multiple inheritance.

Nothing is exactly what it seems but everything with seems can be unpicked.

Krishnatv5-Sep-07 0:46

Krishnatv

5-Sep-07 0:46

Thank you for Nice reply.

Vaclav_5-Sep-07 3:06

Vaclav_

5-Sep-07 3:06

Am I correct to say that if you build you own class - not MFC based - than you can do multiple inheritance in MFC "enviromwent"?

led mike5-Sep-07 4:34

led mike

5-Sep-07 4:34

Matthew Faithfull wrote:
Have a look at some of the tricks ATL uses aswell with template paremters used for base classes; an alternative powerful technique that can sometimes meet your requirements instead of using multiple inheritance.

That seems to say "use the ATL technique "instead of" multiple inheritance" Confused | :confused:

get it to clipboard

josip cagalj4-Sep-07 22:33

josip cagalj

4-Sep-07 22:33

Is it possible to 'tell'(force) a program to perform copy to clipboard(ctrl+C)?

Re: get it to clipboard

Russell^'4-Sep-07 23:36

Russell^'

4-Sep-07 23:36

can it help? Smile | :)

if ( !OpenClipboard() )
  {
     AfxMessageBox( "Cannot open the Clipboard" );
     return;
  }
  // Remove the current Clipboard contents
  if( !EmptyClipboard() )
  {
     AfxMessageBox( "Cannot empty the Clipboard" );
     return;
  }
  // ...
  // Get the currently selected data, hData handle to
  // global memory of data
  // ...
  // For the appropriate data formats...
  if ( ::SetClipboardData( CF_??, hData ) == NULL )
  {
     AfxMessageBox( "Unable to set Clipboard data" );
     CloseClipboard();
     return;
  }
  // ...
  CloseClipboard();

Russell

Re: get it to clipboard

Hamid_RT5-Sep-07 0:42

Re: Illegal System DLL Relocation

5-Sep-07 0:42

See All you ever wanted to know about the Clipboard[^]

[Message Deleted]

shell34-Sep-07 22:32

shell3

4-Sep-07 22:32

[Message Deleted]

Hamid_RT5-Sep-07 0:43

Re: Illegal System DLL Relocation

5-Sep-07 0:43

Did you get this message when you want to load any dll?

Waldermort5-Sep-07 1:18

Re: Illegal System DLL Relocation

5-Sep-07 1:18

The problem is not related to your code but to some of the third party applications you may have installed. Try uninstalling KB925902 hotfix, and/or any software upgrades you have recently installed.

Waldermort5-Sep-07 1:37