Re: Doc/View question

From:

Goran <goran.pusic@gmail.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

Tue, 4 May 2010 23:38:39 -0700 (PDT)

Message-ID:

<345ee306-9d9e-48d9-83ee-d006226a3594@e35g2000yqm.googlegroups.com>

On May 5, 4:12 am, "RB" <NoMail@NoSpam> wrote:

   I have reached a point where I need input on the following:
For some time I have used MFC created apps with Doc/View
and made my base view class as CFormView. It was
convenient and quick, but I was putting all of my data variables in
the ViewClass since that was where the class wizard put all my
control variables and it seemed convenient in my ignorance. If I
had to access files I used ofstream from within my view class.
  So now it has become apparent that I have things backwards
(so it appears from what I read ) in that I should have been creating
data variables in the CDocument class.
    My problem in understanding some of the logistics is that I see
plenty of example code "getting" data into the view from the document,
but I don't see much on getting the user input from the view to the
document. At first I thought I could just make the view class a friend
of the document, but I think maybe that is not the way it is done. So
I am assuming you get a CDocument ptr as I have at the bottom of
shown code below, (appreciate all comments on my understanding
of theory (or not understanding ) and code criticism of how I am
attempting to feed input data to variables in Document class.

CMyView::CMyView() // start of pr=

edicated view code

: CFormView(CMyView::IDD)
{ // Edit Control Variables
  //{{AFX_DATA_INIT(CMyView)
  m_Invert_In_1 = 0.0;
  m_Invert_Out_1 = 0.0;
  m_InletNum = 0;
  //}}AFX_DATA_INIT

}

CMyView::~CMyView()
{

}

void CMyView::DoDataExchange(CDataExchange* pDX)
{
  CFormView::DoDataExchange(pDX);
  //{{AFX_DATA_MAP(CMyView)
  DDX_Text(pDX, IDC_Invert_In_1, m_Invert_In_1);
  DDX_Text(pDX, IDC_Invert_Out_1, m_Invert_Out_1);
  DDX_Text(pDX, IDC_ItemLabel, m_InletNum);
  //}}AFX_DATA_MAP

} =

// end of predicated view code

void CMyView::OnEnter() // Begin question code area
{
  UpdateData(TRUE);
  // Code here is asking for comment and design theory input //
  // I am moving edit control variables input to my data variables
  CMyDoc* DocPtr = GetDocument();
  DocPtr->InletA->dInvert_In_1 = m_Invert_In_1;
  DocPtr->InletA->dInvert_Out_1 = m_Invert_Out_1;
  DocPtr->InletA->uiInletNum = m_InletNum;}

--------------- predicated variables in document class
class CMyDoc : public CDocument
{
  protected: // create from serialization only
  CMyDoc();
  DECLARE_DYNCREATE(CMyDoc)

// Attributes
  public:

  struct Inlet
   { double dInvert_In_1;
     double dInvert_Out_1;
     unsigned int uiInletNum;
   };

  Inlet InletA;
................rest of document class......

That should cover it. Don't forget "if (UpdateData(TRUE)) { transfer
from view to doc } ("if" is important, that's how UpdateData is
supposed to work). Also, don't forget to call UpdateAllViews upon the
change to the document (that's how doc/view is supposed to work).

Goran.