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Tox, how is it much better? Do I write in thin air? If i edit OnCancel(), then will it not change the whole good functionality of the button? I accept, I edit the OnCancel() and the dialog won't close on pressing the Escape then what about clicking the cancel button dude? Don't tell me you did not know this. Please explain tox. I knew mike's solution already and still I think PreTranslateMessage is best.
Regards,
Rajesh R. Subramanian
You have an apple and me too. We exchange those and We have an apple each.
You have an idea and me too. We exchange those and We have two ideas each.
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That approach seemed to stop the dialog box from begin closed by any means so I ruled it out. I don't actually remember him saying he uses MFC, but that seems to be assumed in this forum. I try to steer clear of MFC in my own projects although I use it extensively at work. The MFC source code is a valuable resource however.
Steve
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Stephen Hewitt wrote: That approach seemed to stop the dialog box from begin closed by any means so I ruled it out.
you dont put for both onok and oncancel, just the oncancel will do in this case.
-Prakash
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When I test just OnCancel and stopped it calling CDialog::OnCancel the dialog can't be closed by any means other the pressing "OK". This includes the "x", the system menu and escape.
Steve
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I knew this other solution well before I had posted the PreTranslateMessage handling solution. But it will just change the functionality of OnCancel() too. If i write my code in OnCancel(), not to close, then on clicking the cancel button too, the dialog won't close. Don't tell me you did not know this please. I might want to do something else on OnOk() too. Handling the pretranslatemessage is not a big job. And its powerful than any other way when you work with MFC. I cannot think of any other easier and powerful way to do this. If you know something else which is REALLY APPROPRIATE and RELEVANT, please let us know too. Thanks in advance.
Regards,
Rajesh R. Subramanian
You have an apple and me too. We exchange those and We have an apple each.
You have an idea and me too. We exchange those and We have two ideas each.
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it all depended on the design on the dialog box. Instead of traditional IDCANCEL a different id say ID_CANCEL button can be added to the dialog which could call the baseclass OnCancel to cancel the dialog.
from your reply you look like pissed off, just chill baby.
-Prakash
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Huh? I am not pissed or anything. I think its absolutely waste to rename ID_CANCEL and then write code inside that oncancel function and all. If it is Just for the sake to argue, you can continue to rename everything and modify functions. Its that you know what it is and still you want to rename something and then edit existing functionality or add a button separately to close,,,..... Phew! I am tired. I will continue to use Pretranslatemsg.
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 Prakash is talking to me. What is ur problem
You have an apple and me too. We exchange those and We have an apple each.
You have an idea and me too. We exchange those and We have two ideas each.
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i had been reading this thread. i thought PreTranslateMessage() is better. i always use that only. he told anybody using PreTranslateMessage() is pissed. so i replied.
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Aljechin he told anybody using PreTranslateMessage() is pissed.
talk about misinterpretation. 
-Prakash
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wow, cool down, i didnt say using pretranslate message is a bad way of using it, Like I said it would all depend on the design of the dialog.
-Prakash
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Yeah, but the "x" button and the system menu close functions don't work then.
Steve
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Exactly! That is what I am talking about and trying to explain, but he is talking something else. Either he is not understanding what we tell or he does not know it or he understands it, but just wants to argue. Leave him there.
Regards,
Rajesh R. Subramanian
You have an apple and me too. We exchange those and We have an apple each.
You have an idea and me too. We exchange those and We have two ideas each.
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Have you ever made a pie before?
-Prakash
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Hi Mike,
Is handling the PreTranslateMessage() better or the one which you have given is better? How? My opinion is that when you write code inside the OnCancel() it will modify the functionality of the cancel button (and the close button of the window) too! Which in turn will stop the dialog from closing somehow.. Should another button be added to close then? Is this approach right? I am asking because I am a big fan of you and I need the reason behind your approach in this matter.
Regards,
Rajesh R. Subramanian
You have an apple and me too. We exchange those and We have an apple each.
You have an idea and me too. We exchange those and We have two ideas each.
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In general, the higher-up the call stack that you can make a change, the better. Doing it on OnCancel() is as high up as you can go. The reasoning being, the higher-up layers are less likely to change between versions of MFC (thus breaking your code), and higher-up changes are easier for others to maintain.
PreTranslateMessage() deals with the raw messages, you may perhaps run into weird cases regarding key states, shift states, and so on.
--Mike--
Visual C++ MVP 
LINKS~! Ericahist | NEW!! PimpFish | CP SearchBar v3.0 | C++ Forum FAQ
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Hey Michael,
Is there a way to identify how OnCancel message was called? i.e. by clicking on the button or pressing the ESC key.
thanks
-Prakash
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I've never had to do this myself, but if there is a difference, it would be in the WM_COMMAND parameters - you could compare what wParam and lParam are in those two cases, and then you'd know what you check for.
--Mike--
Visual C++ MVP 
LINKS~! Ericahist | NEW!! PimpFish | CP SearchBar v3.0 | C++ Forum FAQ
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Michael Dunn wrote: In general, the higher-up the call stack that you can make a change, the better.
Very good. But if it does not just solve the purpose, then I do not think it it is a sin to move a little lower into the stack! I read this same solution in your FAQ also. But it just is not the way to do it.
Doing this will stop the dialog from closing by clicking the cancel button or the X button even. However it may prevent the dialog from closing on 'Escape' button press. But to solve a problem, I do not want to run into other problems.
<bold>How will i ever close the dialog then?</bold> Add another button for it? Huh?
Michael Dunn wrote: you may perhaps run into weird cases regarding key states, shift states, and so on.
Nothing weird. Shift state is readily available at GetKeyState(). I strongly believe that you would edit your FAQ also. Think on it!
Regards,
Rajesh R. Subramanian.
You have an apple and me too. We exchange those and We have an apple each.
You have an idea and me too. We exchange those and We have two ideas each.
-- modified at 2:03 Wednesday 25th January, 2006
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I have read in a couple of places that unions should not be used unless its very essential!
I do not understand why? sometimes I create unions with many struct in it.
Does any one has any idea on why unions should not be prefered ?
-Prakash
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Unions are not "type" safe since the same data element can be represented by two different types.
a programmer traped in a thugs body
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ky_rerun wrote: Unions are not "type" safe since the same data element can be represented by two different types.
Well that is whole purpose of unions, plus there are many other data types which are not type safe.
-Prakash
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ky_rerun wrote: Unions are not "type" safe since the same data element can be represented by two different types.
i guess you have a good point
check here http://www.weirdrealm.com/prog/cppstds.html[^]
it says,
Unions
Avoid unions, as they defeat strong type-checking and are very difficult to verify in a debugger.
-Prakash
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Members of unions cannot have an incomplete type, type void, or function type. Therefore members cannot be an instance of the union but can be pointers to the union type being declared.
A union type declaration is a template only. Memory is not reserved until the variable is declared.
If a union of two types is declared and one value is stored, but the union is accessed with the other type, the results are unreliable. For example, a union of float and int is declared. A float value is stored, but the program later accesses the value as an int. In such a situation, the value would depend on the internal storage of float values. The integer value would not be reliable.
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