SendMessage from modaless dialog to the view in SDI without document/view structure support--another method

I create one SDI without document/view structure support, i name the project as ImagePro, then I can get the following files:

ChildView.cpp; (class CChildView : public CWnd， OnPaint() is here)
MainFrm.cpp; (class CMainFrame : public CFrameWnd)
ImagePro.cpp;(class CImageProApp : public CWinApp)

I also create CModalLessDlg using the dialog template, which is defined in ModalLessDlg.cpp and ModalLessDlg.h

In the  ModalLessDlg.cpp, I want to press the "Begin" button to send the "view" a message

you can realize it like this:

1. in ChildView.cpp

#include "ModalLessDlg.h"

void CChildView::OnModalLess() // show the modalless dialog
{

    CModalLessDlg* instance = new CModalLessDlg(this);
    instance->Create(CModalLessDlg::IDD,this);
    instance->PARENT = this;  
    instance->ShowWindow(1);

}

2. in ModalLessDlg.h

#include "ChildView.h"



public:

CChildView *PARENT;

3. in ChildView.h

public:

void     setDisplayText(CString src);

private:

CString   displayText;

4. in ChildView.cpp

CChildView::CChildView(): displayText(_T("zhiguang"))
{
}



void CChildView::setDisplayText(CString src)
{
    displayText=src;
    Invalidate(TRUE);
}



void CChildView::OnPaint() // show different results of image 
{


  CPaintDC dc(this); // device context for painting   
  CRect rect;
  GetClientRect (&rect);
  dc.DrawText (displayText, -1, &rect,DT_SINGLELINE | DT_CENTER | DT_VCENTER);

}

5. in ModalLessDlg.cpp

void CModalLessDlg::OnBegin() // 
{

  CString str_sent="OnBegin is running!";
  PARENT->setDisplayText(str_sent);
}

that is all.

it is using ChildView as one parameter to construct the modaless dialog, then you can easily use the ChildView and its members to change the client area.