Subclass CDialog

[ahoodin]

I would like to subclass CDialog, to add functionality.
I can pretty easily subclass stuff in non-MFC applications.
How do I code that. I would like to substitute my new class for existing dialogs that use CDialog class.

Help me please!
Asher

 

[Zyrenthian]

The easiest way would be to go through the wizard. Design your dialog, right click it, class wizard, and create the class. It will automatically be added to the project.

Matt

 

[ahoodin7]

What about the existing dialogs that already have been subclassed from CDialog. I want to use multiple inheritance, and how would I go about that?

1 I use CDialog as my base class.

2 in the header: class Csubtest : public CMyDialogClass
where it used to be: class Csubtest : public CDialog

Shouldnt that be enough? What other things am I overlooking?

ahoodin

 

[Zyrenthian]

Nope... looks right to me.

If you created a dialog or any control that had a specific ability (lets say drag and drop enabled).

So the big picture.

class MyDragDropDlg: public CDialog

and then if you wanted another dialog to have the properties of the DragAndDropDlg you could just create that dialog as I mentioned above and change the inheritance from public CDialog to public MyDragDropDlg

Matt

 

[ahoodin7]

I get an error on CDialog:oModal() on
the first line

ASSERT(m_lpszTemplateName != NULL || m_hDialogTemplate != NULL ||
m_lpDialogTemplate != NULL);

all these member vars are 0
ahoodin

 

[Zyrenthian]

are you calling DoModal with a pointer or an object? You may need to call "CreateWindow"

Matt

 

[ahoodin7]

Here I am calling it like this:

Csubtest mytest;
mytest.DoModal();

CExistingDlg::CExistingDlg(CWnd* pParent /*=NULL*/)
: CMyDialog(CTestresizeDlg::IDD, pParent)
//was CDialog
{
m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}



when I left it as CDialog, it errored out saying somthing about not taking 2 parameters.

ahoodin

PS: I have to be able to replace all the dialogs whether I call them with DoModal or not!

 

[Zyrenthian]

I believe what you need to do is this

CExistingDlg::CExistingDlg(CWnd* pParent /*=NULL*/)

: CMyDialog(pParent)

//was CDialog
{
    m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}

if CMyDialog had a constructor that took 2 parameters then I am not sure why you are seeing the error that you are.

Matt