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Creating an SDI/MDI application that is initially maximized​

To Creating an SDI/MDI application that is initially maximized Pass SW_SHOWMAXIMIZED as paramater to m_pMainWnd->ShowWindow() in the in the CWinApp::InitInstance()

// SDI/MDI application that is initially maximized
BOOL CWindowTitleApp::InitInstance()
{
 :
 :
 ////////////////////////////////////////////////////////////////////////////
 // To Create an SDI/MDI application that is initially maximized           //
 ////////////////////////////////////////////////////////////////////////////
 m_pMainWnd->ShowWindow(SW_SHOWMAXIMIZED);
 ////////////////////////////////////////////////////////////////////////////
 m_pMainWnd->UpdateWindow();
 m_pMainWnd->DragAcceptFiles();
 return TRUE;
}

Creating a CDC from a HDC​

If we get handle to a DC and sometimes we might want to create a CDC from that. One example is owner-drawn lists, combos, and buttons. we will receive a draw item message with a hDC. The below code can be used to convert hdc into CDC.

// NOTE: This technique for any of the other MFC class/ Windows handle pairs too.
// Creating a CDC from a HDC
void MyList::DrawItem(LPDRAWITEMSTRUCT lpDrawItem)
{
 CDC* pDC;
 pDC = CDC:FromHandle(lpDrawItem->hDC);
}

To fill the Background of the client area with a bitmap​

 BOOL CMySDIView::OnEraseBkgnd(CDC* pDC)
{
 CDC mymem;
 //Create a dc to represent display surface
 mymem.CreateCompatibleDC(pDC);
 
 CBitmap bmp;
 bmp.LoadBitmap(IDB_MYBITMAP);
 mymem.SelectObject(&bmp);
 
    //BitBlt Copyes bitbamp from source (mymem) to destination (pDC)
 pDC->BitBlt(0,0,740, 520, &mymem,0,0, SRCCOPY);
 return 1; // CView::OnEraseBkgnd(pDC);
}

To fill the Background of the client area with a desired color keeping the text in the client area unchanged​

BOOL CMySDIView::OnEraseBkgnd(CDC* pDC)
{
    CRect r;
    //GetClientRect gets the width & height of the client area of             
    //the window
 GetClientRect(&r);
 CBrush br(RGB(255,250,100));
 pDC->SelectObject(br);
 pDC->FillRect(r,&br);
  
 return TRUE;
}

MFC Dialog creation​

Use the CWnd::CenterWindow method to center the dialog. Write CenterWindow() method in the OnInitDialog() method.

BOOL CMyDialog::OnInitDialog()
{     
    CenterWindow();
    return TRUE;
}

Programmatically terminate MFC application​

MFC does not provide a public function to exit an application. The following method shutdowns the Application. The method simply sends a WM_CLOSE message to application’s mainframe window.

void CmfcApp::ExitApplication()
{
     if(AfxGetApp()->m_pMainWnd != NULL))
     {
          AfxGetApp()->m_pMainWnd->SendMessage(WM_CLOSE);
     }
}

Limiting the maximum and minimum sizing of a Frame Window​

  1. Define Min and Mix size in pixels
  2. Handle the WM_GETMINMAXINFO message in a CFrameWnd derived class. The MINMAXINFO struct sets limits on the entire window, we need to take into account scroll bars, toolbars, etc
// Min and Mix size in pixels
#define MINX  500
#define MINY  300
#define MAXX  600
#define MAXY  400
void CMainFrame::OnGetMinMaxInfo(MINMAXINFO* lpMMI)
{
  CRect rectWnd;
  CRect rectClient;
  GetWindowRect(&rectWnd);
  GetClientRect(&rectClient);
  // get offset of toolbars, scrollbars, etc.
  int nWidthOffset = rectWnd.Width() - rectClient.Width();
  int nHeightOffset = rectWnd.Height() - rectClient.Height();
  lpMMI->ptMinTrackSize.x = MINX + nWidthOffset;
  lpMMI->ptMinTrackSize.y = MINY + nHeightOffset;
  lpMMI->ptMaxTrackSize.x = MAXX + nWidthOffset;
  lpMMI->ptMaxTrackSize.y = MAXY + nHeightOffset;
  CFrameWnd::OnGetMinMaxInfo(lpMMI);
}

Centering an Application Frame Window to desktop​

To center Application’s Frame Window call CenterWindow() in MainFrame’s OnCreate() fucntion. See the code snippet below

int CMainFrame::OnCreate(LPCREATESTRUCT lpCreateStruct)
{
  if (CFrameWnd::OnCreate(lpCreateStruct) == -1)
   return -1;
  //////////////////////////////////////////////////////////
  //  Center Application Frame Window                     //
  /////////////////////////////////////////////////////////
  CWnd* pWnd = GetDesktopWindow();
  CenterWindow(pWnd);
  //////////////////////////////////////////////////////////
  return 0;
}

Minimal MFC Window​

We need at least two clases derived to construct an window

  1. Window class / Frame class CMainFrame which is derived from CFrameWnd
  2. Application class CMyApp which is derived from CWinApp
#include <afxwin.h>
class CMainFrame : public CFrameWnd
{
public:
      CMainFrame()
      {
            Create(NULL, "HELLO MFC");
      }
protected:
      afx_msg void OnPaint()
      {
       CPaintDC dc( this);
       dc.TextOut(100, 100, "This is the my MFC window" );
      }
      afx_msg void OnLButtonDown(UINT nFlags, CPoint point)
      {
            AfxMessageBox( "Mouse OnLButtonDown !!");
            CFrameWnd::OnLButtonDown(nFlags, point);
      }
       // Declare the Message Map
      DECLARE_MESSAGE_MAP()
};
// Define the Message Map out side the class Definition
BEGIN_MESSAGE_MAP(CMainFrame, CFrameWnd)
      ON_WM_PAINT()       // Paint Message
      ON_WM_LBUTTONDOWN() // Mouse LButton down message
END_MESSAGE_MAP()


class CMyApp : public CWinApp
{
public:
       virtual BOOL InitInstance()
      {
            m_pMainWnd = new CMainFrame();
            m_pMainWnd->ShowWindow(SW_SHOWNORMAL);
            m_pMainWnd->UpdateWindow();
             return TRUE;
      }
};
// The one and only Application Object
CMyApp theApp;

Making first MDI child window start out maximized​

To make first MDI child window start out maximized

  1. Add a ActivateFrame() which is a CChildFrame virtual function
  2. Modify the function with the below code snnipet
void CChildFrame::ActivateFrame(int nCmdShow)
{
       ////////////////////////////////////////////////////////////////////////////
       // To make first MDI child window start out maximized                     //
       ////////////////////////////////////////////////////////////////////////////
      m_pMainWnd->ShowWindow(SW_SHOWMAXIMIZED);
      
    // if another window is open, use default
    if(GetMDIFrame()->MDIGetActive())
      {
        CMDIChildWnd::ActivateFrame(nCmdShow);
      }
    else // else open the child window maximized.
      {
        CMDIChildWnd::ActivateFrame(SW_SHOWMAXIMIZED);
      }
       ////////////////////////////////////////////////////////////////////////////
}

Remove ‘Untitled’ window caption​

  1. Override the PreCreateWindow() function in CMainFrame class
  2. Modify the CREATESTRUCT style by adding the below code
BOOL CMainFrame::PreCreateWindow(CREATESTRUCT&amp; cs)
{
  if( !CFrameWnd::PreCreateWindow(cs) ){
   return FALSE;
  }

  ////////////////////////////////////////////////////////////////////////////
  // To remove 'Untitled' in main window caption //
  ////////////////////////////////////////////////////////////////////////////
  cs.style &= ~FWS_ADDTOTITLE ;

  return TRUE;
}