Creating a View on a Dialog

 Creating a View on a Dialog

(continued)

-->

Environment: NT4 SP3

Creating a view on a child frame is a basic action when programming in MFC, but what happens when you want your view to be attached to a popup dialog? This article shows a simple way to make this possible.

The idea is to create the view in the usual way (through the document template, for example), and then have the dialog set as the parent. The previous parent--probably the child frame--should be stored and set back when the dialog is destroyed. Two more steps are needed:

1. You should hide the previous parent window.
2. You should override the OnMouseActivate method in your view in order to prevent an assertion in the base implementation

// =============================================






// In the creator window --






// =============================================









// when you want to show the view






void



 CViewOnDlgView::OnShowdlgBtn()


{





  // Add the desired document template




  CDocTemplate* pDocTemplate = NULL

;


  pDocTemplate = new

 CMultiDocTemplate(


    IDR_INNERVIEW,


    RUNTIME_CLASS(CrInnerDoc),


    RUNTIME_CLASS(CChildFrame),


// custom MDI child frame




    RUNTIME_CLASS(CrInnerView));


  AfxGetApp()->AddDocTemplate(pDocTemplate);





  // Create an instance of the desired document template




  CString processName;


  bool

 bIsFound = false

;





  CWinApp* pApp = AfxGetApp();


  POSITION curTemplatePos =


              pApp->GetFirstDocTemplatePosition();


  while

(curTemplatePos)


  {


    pDocTemplate =


           pApp->GetNextDocTemplate(curTemplatePos);


    if

 (pDocTemplate)


    {


      pDocTemplate->GetDocString(processName ,


                                 CDocTemplate::docName);


      if

( processName == "InnerView")


      {


        bIsFound = true

;


        break

;


      }


      else




        processName = "";


    }


  }


  if

 (bIsFound)


    pDoc = pDocTemplate->OpenDocumentFile(NULL

);





  // send a message to the view to move itself to




  // the dialog




  POSITION pos = pDoc->GetFirstViewPosition();


  while

 (pos)


  {


    CView* pView = pDoc->GetNextView(pos);


    pView->SendMessage(WM_SHOW_ON_DLG, 0, 0);


  }


}





// =============================================




// In the view you want to put on the dialog




// =============================================







int

 CrInnerView::ShowOnDlg(WPARAM wParam, LPARAM lParam)


{


  // hiding the previous parent




  GetParent()->ShowWindow(SW_HIDE);





  // creating the bearer dialog




  CrPopupDlg dlg;


  dlg.SetView(this

);


  dlg.DoModal();





  return

 0;


}





// this method needs to be overridden to prevent




// an assertion




int

 CrInnerView::OnMouseActivate( CWnd* pDesktopWnd,


                                  UINT nHitTest,


                                  UINT message )


{


  return

 MA_ACTIVATE;


}





// =============================================




// In the bearer dialog




// =============================================







BOOL CrPopupDlg::OnInitDialog()


{


  if

 (m_pView && ::IsWindow(m_pView->m_hWnd))


  {


    // set this as the view's parent and save




    // the old parent




    m_pPrevParent = m_pView->SetParent(this

);


    // resize the view to the measures of the dlg




    CRect rect;


    GetClientRect(rect);


    m_pView->MoveWindow(rect);


  }





  return

 TRUE;


}





void

 CrPopupDlg::SetView(CView* pView)


{


  // saves a pointer to the view we want to attach




  // to this dlg




  m_pView = pView;


}





void

 CrPopupDlg::OnDestroy()


{


  CDialog::OnDestroy();





  // set the previous parent window back as active




  // parent and destroy both windows




  if

 (m_pPrevParent && ::IsWindow(m_pPrevParent->m_hWnd))


  {


    m_pView->SetParent(m_pPrevParent);


    m_pView->GetParent()->DestroyWindow();


  }


}

Downloads

Download demo project - 36 Kb
Download source - 24 Kb