EndDialog in OnInitDialog reopen Dialog by CProbst1

If you can modify your dialog code, and/or your dialogs share a common base class that you can modify, this workaround might be acceptable for you, and resembles the fix to be implemented in the next MFC version. In your dialog class, add a Boolean variable to track whether the dialog was closed by EndDialog:

bool m_bClosedbyEndDialog;

In your constructor or initializer, initialize this variable to false:

m_bClosedbyEndDialog = false;

Add a new function that you will use instead of EndDialog. Have this function set the variable to true, and then call CDialog::EndDialog from within:

void CMyDialog::EndThisDialog(int nResult)
{
     m_bClosedByEndDialog = true;
     CDialog::EndDialog(nResult);
}

Override CDialog::DoModal in your own class, and copy all the code from CDialog::DoModal. Modify the following lines to check the variable, and then reset it:

if (!CreateRunDlgIndirect(lpDialogTemplate, CWnd::FromHandle(hWndParent), hInst) && !m_bClosedByEndDialog)             {
    // If the resource handle is a resource-only DLL, the dialog may fail to launch. Use the
    // module instance handle as the fallback dialog creator instance handle if necessary.
    CreateRunDlgIndirect(lpDialogTemplate, CWnd::FromHandle(hWndParent), AfxGetInstanceHandle());
}

m_bClosedByEndDialog = false;