Accessing members of a dlg class from outside of it

[WiKiDJeFF]

Lets say I have a Dialog called Cdlg. And one of its member is a CButton called bButton. How would I access a function thats a member of bButton such as GetWindowText from outside of the Cdlg class, like a thread.

[CornedBee]

It's a bad idea manipulating MFC objects from a different thread than they were created with. Sooner or later there'll be an assertion fault.

But anything else, simply make the sub-object public. If you have a reference or pointer to the dialog you can then access the sub-object through it.

[WiKiDJeFF]

But looking through the code (The core for the App was made by the wizard I don't know much about MFC) I dont see any instance of the actual dialog being declared, at least not a global one that I can access outside of the Applications class.

[CornedBee]

Then you'll have to declare one.

If this is a dialog-based app the dialog class instance is a local variable of CYourApp::InitInstance(). You need to add a CYourDlg& variable in a place you can access it globally and set it to this dialog instance:

CYourDlg dlg;
g_dlgref = dlg;
dlg.DoModal();
//...

[WiKiDJeFF]

What is g_dlgref? And wont dlg.DoModal() make another dialog appear on the screen?

[WiKiDJeFF]

Ye you were right I got a assertion fault when I moved the mouse over the form. So this doesn't help me since I need a way to get the caption of a button and add items to a list in report view from the thread. How could I do this?

[CornedBee]

Pass the HWND of the dialog to the new thread and create a local CWnd object there (CWnd::FromHandle or better CWnd::Attach).

Then use the standard API wrappers for GetDlgItem etc. to get the button and use SetWindowText to change its text. Same goes for the list view. Create a local CListCtrl object and use CWnd::Attach to attach the HWND of the list view control to it. Then you can use the member functions to manipulate it.

[WiKiDJeFF]

Could I create a local CmyDlg object and then use CWnd::Attach to attack it to the dialog and then use it to manipulate the controls on the dialog?

[CornedBee]

I'm not sure. I've never tried.

[WiKiDJeFF]

How could I get the handle for the window in an MFC app?

[CornedBee]

CWnd::GetSafeHwnd()

[WiKiDJeFF]

I tried this and suprise suprise got another one of our lovely assertion faults:

AfxBeginThread(ScanThread, GetSafeHwnd());

In the thread:

CmyDlg dlg;
dlg.Attach((HWND)pParam);

[CornedBee]

It asserts in the Attach function?

[WiKiDJeFF]

Yup.

[WiKiDJeFF]

Ok, I kinda got it to work, at least when I use _beginthread to start the thread.

[CornedBee]

Should still be AfxCreateThread in an MFC app...

[WiKiDJeFF]

How bad is it that I'm using _beginthread instead? Any ideas why AfxBeginThread wouldn't work? It seemed to be passing the hwnd parameter wrong.

[CornedBee]

AfxBeginThread creates a CWinThread object, which does some initializing in its constructor.
MFC 7.0 doesn't seem to rely on its usage, but you never no.