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The derived one will be called.
This will be decided at run-time, as the pointer is pointing to a derived class, the derived class version should be called.
--
"Programming is an art that fights back!"
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You are correct. Let me give the snapshot.
class BaseClass
{
public:
virtual void Display();
};
void BaseClass:isplay()
{
printf("Hello BaseClass\n");
}
class DerivedClass : public BaseClass
{
private:
void Display();
};
void DerivedClass:isplay()
{
printf("Hello DerivedClass\n");
}
int main(int argc, char* argv[])
{
printf("Hello World!\n");
BaseClass* pBaseClass = NULL;
DerivedClass* pDerivedClass = new DerivedClass();
pBaseClass = pDerivedClass;
pBaseClass->Display();
delete pDerivedClass;
return 0;
}
In this case the method is private in the derived class, so if we can call this private method from another class then what is the meaning of encapsulation in C++?
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Yajnesh Narayan Behera wrote: In this case the method is private in the derived class, so if we can call this private method from another class then what is the meaning of encapsulation in C++?
buddy that calling the method which is declared public in base class, though it pointing to the address of private method of derived class.
static Binding and encapsulation are eligible till compile time, where compiler check daat integrity and language rule.. runtime check is not applicable in c++. thats why you could even call private member at runtime with twist!
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
Never mind - my own stupidity is the source of every "problem" - Mixture
cheers,
Alok Gupta
VC Forum Q&A :- I/ IV
Support CRY- Child Relief and You/xml>
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I have a exe file (Pinnacle Media Centre TV Tuner card Application)that displays Video from Camera ,I Want that Video to be displayed inside a Dialog Based Application as a small window area..
I tried EnumWindows and ita callback function i am not able to get the Application Handle
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Check if they provide an ActiveX that does more or less the same as the application. If that's the case, then insert this ActiveX into your dialog application.
If they don't, then I don't think this is possible to embed one application into another (at least, not that I'm aware of).
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check, is it provide you any activeX component for adding into the dialog box
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
Never mind - my own stupidity is the source of every "problem" - Mixture
cheers,
Alok Gupta
VC Forum Q&A :- I/ IV
Support CRY- Child Relief and You/xml>
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No I dont have any ActiveX control for that application 
S.K
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No I dont have any ActiveX control for that application [Frown]
S.K
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Hi all,
Please tell me how can color a button without using of bitmap.
Please tell me how can i color a button.
Thanks in advance.
IN A DAY, WHEN YOU DON'T COME ACROSS ANY PROBLEMS - YOU CAN BE SURE THAT YOU ARE TRAVELLING IN A WRONG PATH
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Search in the code project for "Owner draw button".
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can someone show me how I can read and display checkbox value(True/False)and display it into listbox.
VEdb.Open("ICTNAS.mdb"); // Open Clients.MDB
rveSet.Open(AFX_DAO_USE_DEFAULT_TYPE,"SELECT * FROM ExcludedUsers ",NULL);
while(!rveSet.IsEOF()) // Do until EOF
{
int i = 0;
bdate = rveSet.GetFieldValue("Ban Date");
csbDate = bdate.Format();
m_ViewExclusions.InsertItem(i,csbDate,0);
rveSet.GetFieldValue("Student Name",var);
SName =(LPCSTR)var.pbstrVal;
i=i++;
rveSet.MoveNext();
}
rveSet.Close();
VEdb.Close();
}
Thank s
Gpat
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GPat24 wrote: ...display checkbox value(True/False)and display it into listbox.
See here and here.
"Love people and use things, not love things and use people." - Unknown
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
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I am not after a ckeckbox list, all i want to do is to read a checkbox value from database and display it accordingly (true/false) in a list box. I am able to read rest of the fields but not the check box...
any help would be nice
thanks
Gpat
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GPat24 wrote: ...all i want to do is to read a checkbox value from database...
It is a BOOL, which is actually an int.
"Love people and use things, not love things and use people." - Unknown
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
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Hello,
I have a Win32 dialog that is created using CreateDialog and dlgProc is the call back method for that dialog. I have n number of controls on the dialog. When i click on any control the dlgProc receives WM_COMMAND only after mouse click is released. I have scenario where something has to be done on mouse press and some other thing on mouse relese. i am unable to implement this. Any help would be appreciated.
Thanks,
Hari krishna.
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WM_COMMAND comes about because of the detection of a WM_LBUUTONDOWN followed by a WM_LBUTTONUP occuring on the same control. Handle those messages yourself instead of the WM_COMMAND.
Judy
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Thanks Judy. I tried handling WM_LBUTTONDOWN for mouse press but this is called if user clicks on the window not on the controls on the window. If clicked on the controls (for ex: Button) dlgProc doesn't receive this message.
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2 things
1) override OnParentNotify in the dialog class
2) remove the style WS_EX_NOPARENTNOTIFY from each of the dialog controls you want to receive messages for
Judy
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You'll need to subclass the control(s) to intercept the appropriate mouse messages
before the control's window proc handles them.
Subclassing Controls[^]
Mark
Mark Salsbery
Microsoft MVP - Visual C++
![Java | [Coffee]](https://codeproject.global.ssl.fastly.net/script/Forums/Images/coffee.gif)
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Hello All,
Thanks for your reply.
I learnt that subclassing is nothing but having a call back method which handles events for the control.
I have one more question. I have 30 controls on the dialog, do i need to have a call back method for every control or can i handle events related to all the controls in one call back method.
Thanks,
Hari krishna.
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Adarapu Harikrishna wrote: do i need to have a call back method for every control or can i handle events related to all the controls in one call back method.
With the old SetWindowLongPtr() subclassing method:
Different type controls may have different window procedure entry points so
if you use only one subclass WNDPROC, you'll need a way to call the correct
window proc for each control.
With the newer (XP+) SetWindowSubclass() subclassing method you can use one
SUBCLASSPROC since the system handles routing messages up the subclass chain when
you call DefSubclassProc().
Mark
Mark Salsbery
Microsoft MVP - Visual C++
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Hello Mark,
I have a strange problem after subclassing the controls on the dialog. As you know we can view the caption of the control in Spy++ that comes with Visual Studio.
One of the control is a button and its caption is "&A", & is for shortcut. Before subclassing i could see the whole caption when i select this control in Spy++ and after subclassing i am able to see only "&". I am able to see the correct caption in the Properties of the button. So i am not sure where its going wrong?
Any ideas?
Thanks in Advance,
Hari krishna
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I'm having trouble figuring out how to change the color of text in an edit control when it is disabled; such that the light grey (disabled) is black instead.
Let's just say I have an edit control ('IDC_EDIT1').
CFont font; //in header
font.CreatePointFont(280, "Arial Bold");
CWnd *pWnd = ((CWnd*)GetDlgItem(IDC_EDIT1);
pWnd->EnableWindow(FALSE); //disables window
//now I'd like to change the color of the text so it stays black.
Any help would be greatly appreciated.
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What about making the edit control read-only instead of disabling it?
Mark
Mark Salsbery
Microsoft MVP - Visual C++
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Hrm, actually that a good idea; but, I don't know how to do that, either.
I searched the web a little and found ES_READONLY.
Further reading landed me EM_SETREADONLY.
As I understand it, I need to call SendMessage to the window (editcontrol)
I tried:
pWnd->SendMessage(EM_SETREADONLY);
and
pWnd->SendMessage(ES_READONLY);
But neither work - I am still able to edit the contents.
What am I missing?
thanks.
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